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4l80e shift problems Ken 5-21-05  
I own a 1995 motor home with a 4L80E tranny that at times will not shift out of first. This is an intermitant problem. Any ideas what the cause is?
Re: 4l80e shift problems Peter Kohl 2-15-08  
I have a 94 k 3500 6.5td and no reverse or overdrive.Tranny shop said probably a drum,1700.00 to fix.Ouch.can anyone explain,any chance to fix on my own or replace tranny with a used one? got to be a cheaper way
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Re: 4l80e shift problems justin 3-11-08  
'95 k2500 suburban 5.7/4l80. about two weeks ago the speedometer started acting funny (the gear selector indicator light would turn off and the spedo and tach would go up approx 20 deg, after a few seconds the indicator light would come back on then the spedo and tach would dip way down then come back up to correct), now the shift indicator light dosent come on at all and i only have 2nd gear wether in D 3 2 or 1. park neutral and reverse work fine. i thought it might be a connection at the side of the transmission because i have a pretty bad oil leak at the rear main seal and all the wiring is covered with oil and road gunk, so i cleaned all of the connections but saw no improvement. from what im reading here it sounds like i should be looking for an electrical problem further from the tranny its self. i will be sure to post the answer to my problem as soon as i figure it out.
4l80e shift problems joe 2-14-08  
I have a 1995 chevy pu that has a 4l80e tranny and the reverse gear goes no where and neutral is a forward gear and when put in park when engine is reved it dosent go over 1500 rpm
Re: 4l80e shift problems Greg 12-12-07  
I have a 93 gm 1 ton with 130,000 km with a 4L80e tran. that was re build 5 months ago, i am having the same problem as befor it was re built, I oly have 1st, 2nd and R. i'm no sure if i trust the shop that i took it to because no they want to charge me anothere $300.00 saying that it's the tran. computer. is there a separate computer for the engine and the tran.?
Re: 4l80e shift problems zachery wesly turner 11-21-07  
Trans worked perfect until changed injection pump, now its inlimp mode,
Re: 4l80e shift problems rod cosner 11-25-07  
I have a 92 2500 chevy silverado 4 wheel drive with the 4l80e tranny. trans has started shifting very hard, especially from low to second. also shifts hard from park into reverse. thanks for any help
4l80e shift problems Step 3-16-08  
I have a 93 1 ton 4x4 pick up. It has a 4L80e tranny. It shifts fine through all of the gears and will up shift and down shift until you exceed 45 mph. When it is in the low side of the transfer case there is no problems at all. I pulled the codes out of the transmission and it comes up with code 68. Any clue as to why it down shifts back into 3rd gear until you shut the truck off ?

Thanks... Step
Re: 4l80e shift problems Nol's 12-19-07  
I have a '92 chevy 2500 4wd and the trans can't ID what gear it's in, all the forward gears work fine but i have no reverse, my neutral is a drive gear and when in park it seems to to want to lunge forward but doesn't actually move the truck. Any ideas?
Re: 4l80e shift problems Jarod Davidson 8-31-08  
This is a 1993 GMC 1 Ton 6.2L Diesel with a 4L80E Stock. I purchased a remanufactured tranny, new torque converter and replaced the cooler. After the exchange, the tranny went into rev and backed out, I put it into OD (as always) and it started shifting erradically after about 10-15mph. The speedo was bouncing as well. Thinking that I had the spd sensors reversed, I switched them, and the truck would not go out of 1st. Any help would be greatly appreciated. Thank you in advance, Jarod
Re: 4l80e shift problems Mike 5-28-09  
I have a 2000 chevy,3/4 ton, crewcab, classic bodystyle, 4X4, with 138,000 miles. My problem: sometimes goes from o/d into 3rd and when i stop at a stopsign and take off it shifts like it has a monster shift kit. The only way i can stop this is to turn truck off for about 25 seconds, start it back up & then it runs normally until it does it again, may be within a mile or a cpl days. its done this since i bought the truck over 5 yrs ago. i had the shift solenoids and fluid and filter changed about 4 yrs ago and the problem still happens. Any one know how to deal with this? THANKS
Re: 4l80e shift problems eric 8-5-09  
I have a 1996 3500 crew cab with a big block, all stock with a 4l80e, yesterday I was driving down the highway at 70 and when i accelerated down a hill with cruise on the transmission started to "free wheel " below 1900 rpm on tach then it would crab again when engine revs go up, it got progressively worse but transmission still shits through its gears and no problems on in deceleration
Re: 4l80e shift problems dan terilli 8-10-09  
Hi, i have a deisel step van with a 4l80e transmission, it will shift half of the time but the other half it will not, also seems like it is having trouble grabbing the gears, it happens most of the time at 35mph around the 2nd to 3rd shift, sometimes downshifting back to second as soon as it had engaged 3rd gear
Re: 4l80e shift problems mike 5-5-09  
Iv just puta 4bt cummins in my 97 k3500,w/ the 4l80e i need a wiring scematic so i can make my trans shift.HELP PLEASE!,I did get a TCM & harness out of a 95 c 30 diesel truck
Re: 4l80e shift problems thomas 3-9-09  
I Have a 1993 chevy crewcab 1 ton dually with the 4l80e i am having similar problems with mine i have 1st 2nd and reverse when i reset the computer as soon as it shifts into 2nd it no longer has 1st the drive gear is stuck in 2nd still have reverse and park have replaced the input and output sensors on driverside talked to some transshops and they say since my speedometer isnt working that it wont shift so what i need to know is, is that true and if so how do i fix it
Re: 4l80e shift problems zachery wesly turner 11-21-07  
Re: 4l80e shift problems Dale 10-6-08  
I have a 1993 1 ton dually 6.5 turbo diesel with the 4180 tranny. At times it shifts hard but I have all 4 gears and it upshifts and downshifts normally until I turn the truck off. When I restart it I usually only have the first three gears and there is no downshift to second gear no matter how hard I press on the throttle. It is like the kick down is not working at all. After cooling down completely it might work properly the next time or not. I would really like to get this shifting properly all the time with out the very hard up shifts. I think is is an electrical problem and not mechanical.
Re: 4l80e shift problems matt 2-6-09  
I have a speedometer bounce and erratic shifting on the highway. i already replaced both the speed sensors and their connectors. same problem still there. please help
Re: 4l80e shift problems spencer 6-29-08  
I have a 1994 c2500 6.5L TD with the 4L80E transmission that is having shifting problem simular to others listed here. It is stuck in limp mode till the engine is warmed up. once the engine is warm, it is inlimp mode for the first 0.8 miles and then it will start shifting as it should. As long as the truck doesn't cool down all the way it shifts fine for the remander of the day. had it at the dealers they replaced the vssb and check all the wires. after $400.00 they gave it back without it being repaired. they couldn't find the problem. it was not giving any codes. any help would be appreciated.
Re: 4l80e shift problems JASON 11-10-07  
Re: 4l80e shift problems gary scribner 10-22-05  
I have the same problem as Chris did with a 4l80E, in my '99 K2500 suburban with a 454 (54K miles).

Intermittently, truck does not want to go out of first gear. If you punch it -then it will upshift after letting foot off the gas. Also has problem of not wanting to go into overdrive from 3rd (seems to really be upshift issue for all gears). This first occurred one night when I drove the truck about 7 miles, stopped at traffic light, then truck would not get out of first. When restarting vehicle to make return trip, it upshifted fine.

My mechanic, who I trust implicitly, changed out the speed sensors, but as far as I know, did not mess with the wiring or do any other work. he did of course change out the fluid. The tranny fluid and filter was changed at 42K miles.

After work was done, wife made short trip (1 mile), tranny would not come out of first. On return trip, she said it shifted ok. I also had similar problem on slightly longer trip. Is the solenoid next - mechanic did not see anything else obvious, but then again -I am not sure you will see something obvious with this kind of problem. I have read that the computer might need to be reset. Any truth to that. Thanks.
Re: 4l80e shift problems Raphael 11-1-05  
I have recently bought a used 03 Sierra 2500HD with a 4L80E tarns. After the stereo was replaced the transmission on occasion will go to 2nd gear and stay there. I took it to 3 transmission places to have it diagnosed and all 3 places thought it was a bad solenoid and the trany needs to be rebuild. Since the coincidence with the stereo replacement was too suspicious to me, I decided to check the wiring they did. Sure enough I found out that a fuse marked "IGN" was not making good contact. The trany worked fine since that was fixed. SO CHECK YOUR WIRINGS FIRST!
Re: 4l80e shift problems Bil G 4-18-06  
I have a 95 4l60e with 60 on trans I got on it and it was ok for about 20 min till it started acting like my brake were on when it shifted it to second.so i drove home in 1 st now I have no upshift.fluids clean and reverse and 1st are strong I replaced the whole throutel body and servos
Re: 4l80e shift problems BILL 10-16-05  
1996 C-1500 fresh rebuilt 4L60E, butwillnot go into overdrive. B&M shift improver kit installed also. Any answers would be helpful thanks. BILL
Re: 4l80e shift problems rusty 9-29-05  
Tranny ed makes the typical suggestion when you have too much money. start throwing money at it!! save your money and time,take it to a shop that has the proper diagnostic equipment
Re: 4l80e shift problems Tranny Ed 5-25-05  
Easiest and most likely place to start is to replace both speed sensors on the driver side of the trans. Also be sure the wire harnesses at the sensors are in great shape. Chevrolet makes new pigtail kits if yours are bad. athe sensors are about $20-$25 each and you can replace them yourself if you are mechanically inclined...Ed
Re: 4l80e shift problems Mike Spreng 7-9-05  
I have a 1993 chevy turbo diesel with a 4L80E tranny and i recently pulled the motor to replace a head gasket and ended up haveing to take the transmission out too, so here is the problem. I hooked everything back up and when i put it in drive and start to go the truck rocks back and forth before it shifts and it dont want to shift into overdrive. I took it to a tranny shop and he seems to think it is a shift solenoid, do you think it could be that or something else because i cant see how that could go bad just from taking it out and puting it back in, and if you think that is it where is it located inside or outside of the transmission if you could get back to me that would be awesome and i would really appriciate it.
Thanks Mike
Re: 4l80e shift problems Chris 8-29-05  
I have a 1998 Chevy Crew Cab Dually that won't shift out of first all of a sudden. Granted, last night, which was when this started, I did goose the heck out of it coming out of the driveway, but it drove fine the rest of the night. It was only when I returned home and left again about an hour or so later that I found the problem of high RPM's with no shifting out of first in D. It has reverse, so I wasn't thinking that I may have spun the part that I had done twice before in my 1995 w/a 4L60E called the sun shield?...Not too sure the name really. Does the guage fuse affect this at all as it does starting the truck because of oil pressure not being read?...I'm in a bind and need some help..FAST!

Chris...Somewhere down in Texas
Re: 4l80e shift problems Lee 5-19-06  
I've got a 1998 chev 3/4 6.5td with a 3 speed o/d so i guess thats called a four speed? auto. mine will get up to about 90km/h then the speedometer will bounce down and the engine will rev up, if you stay on the fuel the tach will go from 2500rpm to 3500rpm redlined without feeling any power increase to the wheels at all I fiddled with the electronic boxes on the driver side of the tranny and it seemed to get worse then i drove it and it was better now today back to the 90km/h thing again, PLEASE HELP!!
Re: 4l80e shift problems lostpioneer 6-22-06  
No shifting out of first? The trans is electrical and needs power to shift. Make sure the fuse is clean if so it's in the ign switch were the trans gets it's power. tends to be common problem.
Re: 4l80e shift problems james coleman 6-2-07  
I have a 91 gmc 2500 6.2 diesel 4l80e trans it will not lock up the converter or shift overdrive i have changed the pigtail to the 96 modle and also shifts at 17 and 27 no matter what the throtle pisision is will not down shift computor shows no codes
Re: 4l80e shift problems Brian 8-12-07  
I have a 73 k5 blazer 4X4 5.7L that won't shift out of 1st gear till you hit 40 MPH and when it is ideling in drive it makes this grinding/squeeling sound that seems like it is comming from the torque converter and i haven't checked any of the sensors so that is what i am going to do any sugestions
Re: 4l80e shift problems warren holland 10-19-07  
93 gmc 2500 4wd 4l80e 1st thing in morning hard to shift out of 1st. after cycling through all gears 1 time warming up (couple of miles) it works fine.
Re: 4l80e mehmet 5-9-07  
I neeed ınformatıon about tests and troubleshootıng methods.
Re: 4l80e shift problems dave 2-20-07  
I have 96 gmc crew cab 454 4x4 with 4l80 trans 173000,never had aproblem of any kind with trans pull horse trailer weighs 17000 loaded. but changed fliud & filter every 25000 miles. thought you might want to hear something good about one. never been rebuilt. knock on wood
Re: 4l80e shift problems Bob 10-29-06  
I have a 92 Chevy one ton 4x4, 454 with a 4L80E. The other day while pulling out of a parking lot at about 10 mph the tranny shifted out of overdrive and intoral or reverse (really not sure of N or R,just shocked it happened in the middle of a intersection), truck stopped and I pulled the shifter down into drive with pressure pushing up from the tranny. Drove the truck about 2 miles at 40 mph holding the shifter in drive and shifted to OD,rpm's went up 500 back down then up and lost that gear,put shifter in drive and that worked. Stopped at a Chevy dealer and they never heard of this problem and wanted to make a appointment with the tranny shop they work with. Got home and no reverse, let the truck sit about 3 hours started it up and everything works fine in the driveway. What do you think???
Re: 4l80e shift problems charles 11-14-06  
I have a 2000 chev. 3500 with a 5.7 motor. The 4l80e will shift back to third and go into defalt between 55 and 65 mph. If i cruse at 70 mph it will stay in over drive. What can I do to fix this? Thanks
4l80e shift problems no gears at all Tim 8-20-09  
I have a 97 Dually with 454 and 4l80 trans and it has been going out off and on, when i come to a stop it acts like it is in nuetrual and then it has no gears at all no reverse or any gear. But when you go from park to reverse you fell it like it would when you shift it there and same with drive but when you give it gas it goes no where does anyone have a clue what to look for or to fix this. i think this kind of trans is junk i may try to put one of my th400 in there and get rid of this electronic computer crap trans. But if anyone knows what this could be please let me know Thank you.
Re: 4l80e shift problems Kevin 2-22-08  
#1 check fluid level and colour. If its burnt brown change immediatly.
#2 Check default shifts by removing fuse for tranny. Shifts will be hard but it will shift all 4 gears if no mechanical problem.
#3 check wires to brake switch. Some trucks have up to 3 curcuits on this switch. TCC, Cruise control and brake lights.
#4 check tranny control module ussualy found near computer under dash.
#5 check both speed sensors. Output speed sensor is common problem if it is mounted in tranfer case (hummer h1)
take it out and clean off all the iron filings that have built up.
#6 Chech line pressures ???
#7 Drop the valve body and replace all solinoids and filter. 1-2 solinoids are prone to leaks and will cause many problems like loss of 4th.
If none of that works and assuming your Injection pump(DS4) and the PMD are operational(no codes 1216 1217)its probably inside the tranny. Stator bushings, wave washers and pumps are likly and expensive and last resort. All previous tests can be done with a ratchet set an voltohm meter for free
Hope this helps. 1997 Hummer H1 4door hard top nicely beaten to hell and back.
My GMC makes grinding noise when warmed up and wont drive. Dustin Mooney 8-24-11  
I have a 99 GMC sierra that was converted into a flatbed.. I can go right outside right now and fire it up and drive it a few miles and all is great.. Then I start hearing a spinning grinding noise like the sunshield and I start losing gears.. From reverse to them all.. Let it cool down and itll run a few miles just fine no noise or slipping. help please. I have to get this work truck back on the road.
Re: 4l80e shift problems Charlie Finkbiner 11-20-11  
I have a 93 2500 chevy diesel with 4l80e in it for the past few months the overdrive hasnt been working the scanner had said the tps low so i changed it and it worked for awhile. Now its doing it again plus no first gear the wiring appears to be good in tranny. I really could use some suggestions on what to replace for fix. thanks alot
Re: 4l80e shift problems Adam Knight 1-20-12  
Hello, I have a 94 4L80E 2wd auto trans and it has been shifting perfect till today. Its stuck in first. I drove it about two miles and put it in park,shut it off and started back up and it's driving fine for now. (note I do not have to engage the brake pedal to shift this automatic, the safety switch or something is broke.) the trams oil looks dirty too, but what would cause this intermittent Shift problem??? Thanks for any help
4-wheel drive problems joanna king 8-10-11  
The transfer case in '95 tahoe keeps switching to neutral while driving in 2H... I have no clue what causes this.
Re: 4l80e shift problems Marcio De Maria 8-6-11  
Hello, I have a 1993 454SS Truck, with 4L80e transmission, wich i've just rebuild. It was working fine, but all of a sudden it started to shift gears at 3000rpm, and NO 4th at all. If I push the gas to full throttle, it shifts at 3000rpm, if I drive very slowly, it will not shift until the rpm reaches 3000 rpm. Does anyone have any clue? I need help. Thank you all.
Re: 4l80e shift problems Gerry 12-17-10  
I have a 1991 Suburban 2500 4X4 4180e trans. It has always shifted early and kind of hard. Now after new 02 sensor, TBI spacer, exhaust, cat muffler...
Now it seems to not want to stay in one gear, like it is going between 2nd and 3rd with no OD... There are three speed sensors Input and out put as well as one call vehicle speed sensor on the transfer case which I am taking controls the speedometer, then I read here about ignition switch could cause it, or a plug with wiring inside the trans. Oh or the two shift solenoids inside the pan.
So can someone tell me what to replace first as the most likely cause??? Please. Oh and there are no codes I replaced almost every sensor on the engine to get rid of those as the scanner would not show it was connected to the truck...
Re: 4l80e shift problems dave osborne 5-8-11  
1993 chevy 3500 with 8.2 liter 502 cu in motor and 4l80e trans was rebuilt about 25000 miles ago was working fine then last week would not shift into overdrive checked fluid a little low added some was fine for one week then did it again would not shift into od stopped let it sit for about 2 hours drove it and it shifts fine now any input for me
Re: 4l80e shift problems Brett 5-23-11  
95 G30 van. 5.7 and 4l80e. Good 1-2 and 2-3 shifts, then freewheels at about 50mph. When you slow to 35mph it starts pulling again. Replaced fluid filter and internal wire harness. worked great for 2 weeks, then same problem. Replaced ECM. Worked great for a week. Same problem but, Now getting code 35, idle speed control circuit problem. High idle- 200rpm higher...THANKS...BRETT
Re: 4l80e shift problems patrick 1-26-12  
Have a 93 chev 2500hd trans rebuilt 30,000ago fluid nice.trans works fine when warm out but when 30deg or colder the check engine comes on and trans shifts late each gear and no overdrive.sometimes can shut off and start again and lite goes off and trans shifts but have to let off on gas a little or it wont shift till around 3,000 rpm,allso idles at1,200 when this happens.if start again after warming up seems ok.trany code was 85 gear ratio problem.speedo has been 10 mph fast for quit a wile. idle goes back to normal also after restart warm.trans allways shifts late when first start unless feathered. scratching my head on this one.
Re: 4l80e shift problems Tim 5-21-12  
I have 03 2500HD that free wheels or goes into nuetral while coasting down hill.It also makes a loud whrilling noiseI verrrrrrr)any ideas?
Re: 4l80e shift problems Torey 7-30-16  
I have a 92 gmc Sierra 3500 that is a wrecker that has a 4l80e that hard shifts 1-2 and no tc lockup unless the battery is lest off for a few minutes where Told it could be brake light switch, and noreplaced it and nothing changed, email securetowing757@yahoo.com
Re: 4l80e shift problems Luis 8-8-16  
95 chev P30 my transmission State un the first gear no shift others gears. I replace 3 transmission and still doing the same problem no shift from first gear. Please somebody help me please.
Re: 4l80e shift problems Phil 11-16-16  
Have 91 g30 class c motorhome. Its a chevy G30 one toncab and chassis with a5.7 k and a 4l80 e trany. Strains to shift into third with a slam. Then wont shift to od and feels like its loosing power till i back off throttle. Sure could use some ideas. Any help?
Re: 4l80e shift problems Russell R 6-13-16  
I have a 1996 allegro star motorhome that I had the transmission rebuilt on and this is the first trip on it but is still doing basically the same thing, it's a 4L80E powered by a 454 Chevy engine, the shifts are very light, you can hardly feel them, but I loose speed going up hill, the manual that came with the motorhome says to shift down going up hill, feels like the transmission is slipping and the engine races up but coach still slowing down. anyone have any insight on what I need to do. I was trying to see what type transmission I could change it out to if possible also would like to know if this has a transmission controller located anywhere under the dash that might be a problem. This motorhome is built on a P-30 Chevrolet van chassis.
Re: 4l80e shift problems jeff campbell 8-22-15  
1992 Fleetwood bounder wont shift outa second gear, even takes off in second, how do I fix it?
Re: 4l80e shift problems billy 8-13-12  
01 2500hd 4l80e have to rev it up for tranny to engage once it does shifts fine replaced speed sensors already a while back
Re: 4l80e shift problems BRYAN 9-6-09  
Re: 4l80e shift problems pete 11-15-13  
I have a 94 GMC K3500 4x4. shifts and drives fine but going down hill on decelaration it makes a wirr sound and free wheels. any ideas?
Re: 4l80e shift problems Gerry 12-17-10  
I have a 1991 Suburban 2500 4X4 4180e trans. It has always shifted early and kind of hard. Now after new 02 sensor, TBI spacer, exhaust, cat muffler...
Now it seems to not want to stay in one gear, like it is going between 2nd and 3rd with no OD... There are three speed sensors Input and out put as well as one call vehicle speed sensor on the transfer case which I am taking controls the speedometer, then I read here about ignition switch could cause it, or a plug with wiring inside the trans. Oh or the two shift solenoids inside the pan.
So can someone tell me what to replace first as the most likely cause??? Please. Oh and there are no codes I replaced almost every sensor on the engine to get rid of those as the scanner would not show it was connected to the truck...
Re: 4l80e shift problems Monroe 12-3-12  
I have a 2000 silverado 2500 new body style transmission shifts fine have all gears but when hooked to a load it feels like the brakes are on especially in reverse.
Re: 4l80e shift problems Tim 2-7-10  
4L80E has two solenoids, -- one for 1st and 2nd gear, the other one for 3rd and O/D. They are about $13 each and can be changed from the bottom pan.
No problem. tewilliams1957@bellsouth.net
Re: 4l80e shift problems Charles 2-22-10  
I have a 1996, C3500 1 ton dualy 6.5 turbo diesel 4180e trans. Had fluid changed and trans flushed. About a month later when I put truck in reverse it would take a few seconds for it to engage. Within about 4 days it progressively got worse as to the time it would take to engage. Once it engages it has plenty of power and no slippage. The only problem with the forward gears is that time to time
1st to 2nd and 2nd to 3rd would shift hard rarely. Today when i pulled to a job site and went to back up reverse is totally gone. When I left the site I had no overdrive. about 3 minutes I loose 3rd, and after another 5 minutes I loose 2nd, and 1st is all that is left. Now when I take off I have 1st, hard shift to 2nd, and hard shift to 3rd, but will loose all but first within 10 minutes. The fluid did not seem burnt at first until I had to drive the truck in 1st gear 12 miles to my house but still it does not seem to bad. Whenever any gear including reverse would engage there seems to be no slippage at all. It just either works or it doesn't. I am assuming I need a new transmision but just want to be sure.
Re: 4l80e shift problems David 9-7-09  
My 4l80e tranny in my 1995 gmc 3500 goes into neutral while driving down the highway at 3000 rpms the speedometer will bounce around and then i pull over shut the engine off wait 10 seconds and start it and its fine only does this at about 75 mph please help thanks dave
Re: 4l80e shift problems cyril gollop 10-15-09  
My 1998 1/2 ton C1500 with the 4.3 motor will not shift from 3 to OD. It will up shift from 2 to 3 but will not engage 3.
Re: 4l80e shift problems steve 10-12-09  
1998 2500 4x4 6.5 diesel having problem with converter lockup.
Truck shifts out fine on take off and pulls fine.
But when truck is unloaded and traveling on level or down hill the rpms are up.( no lock up)
When truck is going up hill or incline the rpms are low ( converter lock up)
When there is a no load on engine the throttle seems to jack off an on.
This started after changing injectors.
Any ideas!
Re: 4l80e shift problems Bailey 12-6-10  
My 95 GMC 3500hd 6.5 diesel will not upshift. fluids full clear clean and not burned. 1-2, 2-3, solennoids replaced. Truck had a run away condition and wouldn't shut down until the fuse was pulled. After that the shifting problem showed up. Is it posiable that the throttle position switch on the accelerator failed and caused this problem? Any ideas?
Re: 4l80e shift problems Gord 9-23-09  
I have a 2000 Chevy Silverado 2500 4x4 and it won't shift into third gear. I put my scanner on it and it said ignition switch wirring problem, so I changed the wiring harness fo the ignition switch but know change in the shifting. Can you help? PLEASE! Thanks Gord.
Re: 4l80e shift problems ernie 10-12-09  
Just changed motor from a standard donor truck into mine-with a 4l80e put tps on side of injector pump and changed oil pump drive to the ones that were off the old engine tranny shifts hard it seems from1st to 3rd with no o/d eventually it will shift to o/d after a bunch of shifting from 3rd to o/d tranny was rebuilt a year ago and worked fine till the engine swap any ideas were to check?did not remove tranny or any wireing from tranny just engine
Re: 4l80e shift problems scott 3-8-10  
I have a 2002 chevy 1500 one day leaving work i noticed that my abs light came on then my truck wouldn't shift out of 3rd and my e brake light flashes on. somedays its does it and others it works fine. i am really not sure what the problem could be any ideas.
Re: 4l80e shift problems keandre 3-3-10  
I have a 1994 chevy caprice when i take off it shift find but when i stop in take off it start off with slow speed and than pick up high speed
Re: 4l80e shift problems Bryce 3-22-10  
Hello I have a 1993 chevy dually with a 4l80e. It seems to just have all forward gears even in park it seems to want to go forward. Its also in 1st in the reverse position and all other spots in the on the indicator what in the world is going on as its a brand new rebuilt tranny. I reused the speed sensors and the a and b shift solinoids and ideas would be greatly appreciated.
Re: 4l80e shift problems heath 11-14-10  
I have a 95 suburban, from a stop i took off, heard a bang now have no foward gears, reverse works fine any ideas?
Re: 4l80e shift problems Angela 11-15-10  
I'm having the SAME issue many of you here are and haven't seen many answers... so I'll ask anyways!
1995 GMC Sierra 1500 4x4 first just the speedometer went wonky and ABS light on... then after about week it would shift up and down trying to figure out where it was supposed to be. Finally limp mode. Let sit and rest for 10 min then okay for a bit. Replace TPS and was good for a month. Then bad again. Replaced both wheel speed sensors and good for a road trip from Canada to Vegas... now bad again. Replaced transfer case. Still bad. Codes read that BOTH wheel speed sensors are bad... but they are not. They're new. Now what??? Please ANY thoughts...
Re: 4l80e shift problems harvey 8-24-10  
The trans in my 1994 bounder motorhome equipped with a454 stopped shifting it appears to be stuck in low and i am sitting on the side of the road any solutions to get me going i am a long way from agarage but i am a mechanic
Cruise control stuck Ray Anderson 9-7-10  
Instructions needed to disconnect thecruise control on a 1996 chevy silverado, automatic, 6.5 liter
Re: 4l80e cant get pan to stop leaking mike 6-14-10  
Okay i dropped tranny and rebuilt the pump and replaced front input seal on the tranny and the rear output seal on the transfer case...now i cannot get the stupid oil pan to stop leaking..ive tried the factory reusable seal lol and a replacement rubber type and i even made a gasket grrrrrrrrrrrrrrr to no avail keeps leaking from same two bolts on the passenger side i am about to try the factory with homemade gasket on both sides but would like to avoid this as is not recommended any thoughts???
Re: 4l80e shift problems robert 3-25-10  
I have a 93 3/4 ton 4x4 chevy p/u with 4l80e tranny. i pull a wire out of the plug that goes into the drivers side of trans. trans mission still shifted fine. unplugged from trans and put wire back into plug( it was a orange one) seemed to pop back into place. taped up wires( 11 wires go to this plug). started truck and it no longer upshifts out of 1st gear. checked trouble code and it showed a 1-2 shift soleniod open circut fault. any hint to what might have happened.looks like plug is not in great shape. is there a pigtail repair harness just in case this plug is the problem.
Re: 4l80e shift problems Ryan 5-27-10  
I have a 1991 gmc suburban with the 4L80E transmission. When the vehicle is cold it shifts fine, when it warms up after about five miles or so the tranny drops out gear and goes into first. It does not grind it just feels like it is in neutral. When the vehicle slows down enough for first gear to take over it won't shift back up. The fluid is fine and clean. Could it be the shift sensors or torque converter? Thanks
Re: 4l80e shift problems jeff 3-23-10  
Hello i have an 02 chev with 4l80e shifts hard after 5 miles of 70mph after turning ignnition off it works fine until another 70 mph trip whats wrong thanks jeff
Re: 4l80e shift problems MAX 12-31-10  
Re: 4l80e shift problems STAN STEIER 10-3-05  
Re: 4l80e shift problems Corey 8-2-07  
I have a 94 suburban 2500 with a brand new tranny that wont shift. I get codes 85 and 87 when I scan it. Would this be the input speed sensor causing my problem
Re: 4l80e shift problems Pete 11-5-16  
Have a 93 one ton cube van just out of the blue the speedometer doesn't work ABS light is on and it doesn't shift out of first gear The speed sensor has been changed still has same problem my mechanic says it is the transmission modulator circuitboard I'm not sure if he's right very hard to find and apparently they only put this transmission in this truck from net 93 to 95 so very hard trying to find parts any input or help is greatly appreciated as I have a great truck that I have spent lots of money on maintaining and only has 160,000 K as in kilometres on it hopefully you guys out there I'll have some ideas on what this could possibly be, stressed out and just about out of cash.

HELP,!!! Get my GMC Back working again

Thanks Guys"........Pete.
Re: 4l80e shift problems Jason Jarduck 5-13-09  
I have a 1994 6.5 turbo diesel with a 4L80E automatic transmission. I took it in and got it scanned. It gave a code 87 which is 2-3 shift solenoid failing. I replaced both shifting solenoids one at a time to make sure there was no mix up. I checked wires inside transmission and seen that they were in good shape. I replaced filter and put new oil in the transmission and disconnect batteries to reset computer. I still have the problem the transmission will not shift out of first. The transmission oil is red and is not burnt or even smell burnt. This problem just happen driving down the road where it did not want to shift up.

Please tell me what other areas or sensors could cause this problem to occur.

Thank you

Re: 4l80e hugo de leon 12-28-07  
93 chevy 6.5 t d 4l80e trans wont shift into overdrive what could be causing the problem.thanks
Re: 4l80e shift problems john 10-21-09  
My truck was working fine got in it today wont shift out of low gear check every thing i now would reseting the conputer help this problem is a l480e 1993 chevy diesel 6.5 thanks
Re: 4l80e shift problems N William Snyder 12-13-07  
We seem to be having asimilar problem with our service vehicle. The speedometer goes erratic the transmission starts shifting to the gear that identifies with that speed. Also the ABS light comes on. Terrible for ride and fuel mileage.
Re: 4l80e shift problems mike 3-1-11  
Need to know why trans is in limp mode.
Re: 4l80e shift problems sammy tanner 10-31-11  
I have 1st 2end no shift any futher
Re: 4l80e Christian 6-14-08  
I have a 4L80e in my Impala. With a TCI controler. The problem is that it starts in 2 (unless i manuely put it i 1) an than it shifts to 3 and go in to lock up. I have changede the A&B solonoides (and theck the old ones workede fine) and theckede the valves behind them work smoot. Triede another ECU same thing. changede the wiring in the trans. theckede the outside wiring and is ok. The trans is a pro rebuild (AMT) with a Yank converter. It has all the upgrades it can have. and workede fine when i put it on the car. And drove 40 miles. than it sat of a year. Any idears???
Re: 4l80e shift problems Ed 3-20-09  
Justin, I had the same problem on my 2000 K2500, it was the ignition switch. This is a very common problem. I thought it was the speed sensors, but I read somewhere if the "Gear Indicator" light dimmed or goes out, then its the ignition switch. It solved my problem. Not to bad of a job, but you need a special socket to disconnect switch at the key cylinder. Good Luck.
Re: 4l80e shift problems dale 8-21-11  
1993 chevy k2500 6.5 t.d. 4l80e trans. shift problems hard shift 1 to 2 no o/d what up
Re: 4l80e shift problems Ed O 5-6-09  
My 4l80e in my motorhome 1996 will not shift into 4th or overdrive..meter will not read any codes.,..my mechanic has replaced switch on break pedal
and dosent want to pull trans out because it dosent slip or such..thinks its not trans but electrical but is at a loss for info and which way to go can anyone help!!!
Re: 4l80e shift problems Pete 6-5-09  
Mike check the TCU plug on the driver side of the transmission. When you unplug it and it has fluid in it tour harness will need to be replaced in the trans. GM made an upgrade due to this on older 4l80e but later models due this and the fluid leak thru will deteriate the wires causing all kinds of shifting issues.
Re: 4l80e shift problems doug 7-5-09  
I have a 1995 chev 3/4 ton 4l80e trans it would some times shift 1 to 2 and not shift to 3rd or od,I then stop the truck and turn it off for 2 mins and restart and it works normal. but now it has 1st and 2nd and revs no 3rd or od. and some times has 2 and revs no 1st
Re: 4l80e shift problems travis 11-6-09  
I have replaced shifts solinoid A and B.still no third or over drive.do you now how to help me fix it.
4l80e shift problems xxmymasterxx 3-19-10  
I have 95 chevy tahoe 2wd w/ the 350 in it. the problem is most of the time it only shifts @ hi rpms and often gets stuck @ the rev limiter. i was told to adjust the vacuum modulator. is there a way to do this on the 4l80e. any help would be appreciated
Re: 4l80e shift problems brandon 5-26-11  
I have a 96 silverado that does fine in 1st through 2nd but free wheels in 3rd through 4th. after the rpms are high. when i slow down it grabs back in gear.
Re: 4l80e shift problems Rick 1-23-10  
I have a 1996 silverado and my trans quit goin in to 3rd and 4th it sirts good 1 and 2nd but whin it goes in to 3rd it just free wheels just had trans. rebuilt 6 mouth ago
Re: 4l80e shift problems Lou 2-27-10  
I Have GMC C-3500 HD - 1995 w/220K miles
Trans Rebuilt last year, just run 12.000
miles, Know i have NO REVERSE and FW
shift 1er. and 2nd. gear ONLY.-
Problems.?? speed sensor or reverse

Thank you for answer
Re: 4l80e shift problems ed 12-30-10  
Re: 4l80e shift problems Grant 6-9-13  
1995 gmc 4l80e gm factory reman forward speed senser was not hooked up shift erratic hooked speed senser seems tone missing 1 and 2 jumps into 4 kills engine down to 800 manually into 3 seems to stay in 3. 3000 rpm at 65 kph oil is clean disconnect batteries reconnect makes no difference please help
Re: 4l80e shift problems micah 12-7-12  
Have a 4l80e n 93 suburban tranny has been gone through all parts pron to fail have been replace had shift kit installed still only have first and reverse was told the quad drivers were bad in ecm replaced it checked power at fuse have 12+ volts any ideas where to go from here. thanks
Re: 4l80e shift problems A 3-1-11  
Transmission shifts from 1st to second just fine on my 1993 chevy silverado z71 but when it tries to shift to third all it does is slip causing the engine to increase revs. It will not go into third gear at all.
Re: 4l80e shift problems Aaron 3-25-15  
Ive got an 86 3x3 four wheel drive 6.2l with a 4l80e. It seems to want to pop out of higher gears when under a load and I have to run it up to a very high RPM to get it to stay in gear.... any ideas?
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