4L80e transmission shift issues

Slips out of overdrive once warm and converter will not lock up at anytime

[@bgp19611]

Aluminum valve body wears out the bore on the actuator feed limit bore. Then it falls out of fourth gear. You can repair the valve body with Sonnax part number 34200-16K.

[@harryjones2420]

If you read this, I just got a 2002 gmc savana 3500. The shifting is eratic, speedometer goes up and down, and the ABS works on and off

[@farmguy-hn8fb]

Transmission speed sensor

[@scarsprospecting]

Mine is doing the same thing . Driving back from Arizona to Colorado lost over drive in Albuquerque New Mexico thought my transmission went out, but we made it all the way back to Colorado, Nebraska border and now new Heads and other parts installed having transmission issues

[@javaman2883]

Mine does not have the lockup issue but does loose 4th gear when warmed up. Mine's a 1996 K2500 Suburban 119k miles. I bought it at 112k miles, worked fine then, according to PO records, trans filter and fluid were first changed at 72k miles (100k manufacturer recommended). The fluid looked dark, so I changed it when I got it. The problem started at 115k miles, on a trip near Palm Springs, CA. All gears and lockup work fine when cold, outside < 50. Once it's warmed up, no 4th gear, feel it shift into 4th but a few seconds later feels like neutral and can rev the engine up and down via throttle. Put the shifter in 3rd, I can still feel the converter locking and unlocking appropriately while driving. Been driving it about a year that way, just always select 3rd rather than D.

[@kylemilford5968]

I run 12v ignition to TCC lockup. The ECU itself unlocks the converter at a set speed. No need to worry about faulty brake switch.

[@BNforever2009]

I have a 94 Chevrolet Caprice 9C1 and it wont go into 4th gear. My car has the 4L60E transmission. I plan on getting the transmission rebuilt totally. I will upgrade to the shift kit and add a line lock. I sometimes take the car out for a nice 1 hour cruise in the Chicago southwest suburbs and a nice toll road cruise to DeKalb IL or all the way to Dixon IL and back. When I'm with the car club usually twice a year I run her on the dragstrip. The engine is all stock and I added a new bigger dual exhaust system and Hooker headers. The rear end is already rebuilt and the 3.23 posi is in it.

[@nathanialholdridge9507]

What turned out to be the problem?

[@fordmanx3]

Lockup is awesome i love my RPMS nice and low

[@scarsprospecting]

No follow up video ? How’d it go with the fixes.

[@gasmonkey9600]

From 88 to 97 is a common problem with not shifting into overdrive one of my cousins has a truck that will not go into overdrive when it gets hot so you might try putting a transmission fan in when is cold it will go into 4th gear just fine but once it gets up to temperature it will not

[@mem8304]

gas monkey replace your tps problem fix trust me I just fixed mine

[@emanmoe5711]

TPS? Where is it? Because my truck started doing this today and it’s driving me crazy 🤯🤯🤯🤯 please help

[@nitromyke]

My 1991 K3500 does lose 4th gear randomly... I shut the truck off, restart it, and it drives all its gears for a while after!! Sometimes I drive weeks with no issue, sometimes after 5 minutes of driving it happens!

[@hummerguy]

Got if fixed?

[@nitromyke]

@@hummerguy It did'nt have this issue for the last 3-4 years... I dont drive it as often as I used to, but my OD keeps shifting ok !!

[@hummerguy]

@@nitromyke That's pretty good, I'm changing the internal wiring harness on mines

[@gtemplesrt8]

I've got a question! I just bought a last year 1 ton Squarebody 1991 and after finally getting it to run by changing fuel pumps in both tanks now the transmission is giving out when I put it in park!! Just heard the part about the brake light issue and maybe that could be the issue?! My cable broke weeks ago and the pedal would drop and light would come on but go back off after I lifted the pedal. Now the light stays on!

[@davidrussell6826]

Hi Jay. I'm up the road from you a few miles in Ontario, OR. I appreciate your video. I'm hoping you can help my situation. I couldn't find your follow-up to this video so thought I'd write. I have a 99 Silverado 3/4 ton with the 4L80e trans that, after warm up, downshifts back to "3rd". I do have lock up into OD when in 4th while warming up, though. Other gears seem normal but once the problem shows, it will not shift out of 3rd into 4th. However, if I shut the engine off for a several seconds it will often begin shifting normally into 4th lock-up again. Sometimes it continues operating normally, sometimes it will resume the problem. I don't know as this is related buy one other strange thing I noted a couple of times is that when I restart the engine, sometimes the cruise control will not work. You mentioned something about a brake switch relationship. Otherwise I probably would mention the cruise. How did you make out with the above trans? Did the solenoid and AFL replacement fix your problem?

[@jaychristensen4600]

I did swap out a complete valve body from a different transmission and even tried a different TCM, no changes. I soon after sold my property there in Meridian and sold this vehicle as was. The person that bought it drove it to Garden valley that night (about 60 miles) and had no change. I assumed it was the torque converter but never changed it to confirm, sorry.

[@leoperalta1915]

2007 Chevy suburban Will not go in to over drive Going down the highway What would you recommend Thank you

[@gasmonkey9600]

the truck you have common problems or transmission not wanting to go into overdrive when it gets hot I don't know if you have that problem or not but try shifting up manually

[@homegrownluv8106]

I have a 05 Z71. In 3rd and fourth it feels as if I’m in over drive And when I turn it off I get no change in rpms it’s as if it’s stuck. The only change I see is if I’m in 2nd or 3rd and turn it on I’ll get a change but for the most part in high gear it feels like it’s in over drive constantly. Any help is appreciated. Thx.

[@bobbyatman273]

Try to fill it with thick oil (of course you'd need to fully flush it later) if it goes back to normal - it's AFL valve

[@KevinMartinez-kv5rh]

Can some rear gears help ?

[@farmguy-hn8fb]

My 98 k3550 4l80 transmission and 4:10 rear end. I just got a rebuilt transmission installed and now at 65mph I'm running 3000 rpm before it was 2200. Any suggestions

[@bloolouboyle]

Mine drops out of OD when coasting and it starts screaming--sounds like engine revving but tach shows 800-1000 rpm I tap the gas pedal and it catches again --any Ideas?--thx in advance--have 250k miles--looking for patch fix if possible.

[@MrKendick10]

My 93 Chevy dually is doing the exact same thing. Did you ever figure the problem out

[@MrKendick10]

bloolouboyle did you figure out the problem

[@gasmonkey9600]

or it could be you need a transmission fan general motors before 2000 were really common for overheating in the transmission and not going into 4th gear or lock up

[@KIDZKARTBLDER]

Trent Davis see that’s what mine is doing .. it goes into 4th without lockup and if you let off the gas it will go to an idle but still in gear .. I was told the trans was over heated backing up a Traylor ..

[@gasmonkey9600]

@@KIDZKARTBLDER week week transmission

[@207shenanigans]

What was the fix ?

[@irey1978]

I have a 95 C2500 that is doing the same thing. When it was new I would get lock up in 3rd and 4th, now 3rd never locks up rarely 4th after 48 mph. Did TQ fix the issue ? I have 171,000 miles on mine currently. I don't have drop out to third yet, but have had uncommand natural at speed through but stayed in 4th.

[@robertinman276]

Keith Irey

[@booser420]

Is it safe to tow with it like that mine does the same thing?

[@pmotorsports8276]

Yes the latter models with tow/haul button disables lockup

[@bobbyatman273]

My 4l80e on 2000 GMC C3500 has a leaking plug, when it fills with oil i lose the overdrive and have jerky shift from 1 to 2nd and 2nd to 3rd, when i blow out the plug with air compressor it drives great! Has anyone experienced it? is it the wicking of oil through the plug or is it the outer o-ring seal?

[@lsredneck221]

Drop the pan and change the wiring harness.

[@aaronbecerra4304]

I have the same truck c3500 2000, it shifts 1,2,3 but not 4, and I put another transmisión and same problem, i don't know what to do now, and sometimes it goes from 1 to no other gear or shift, i doesn't change the gears, i don't know what it could be, they told me it is something electric

[@brayli100]

Same problem no 4 I’m dropping the pan to check he harness

[@bobbyatman273]

@@brayli100 HI, I don't believe you need to drop the pan, you won't see anything exciting there, ALL of the plugs I've seen at junk yards LEAK, so I don't believe that causes that problem, I JB welded my plug from the inside, it's not leaking anymore but that didn't fix the problem. In my case it is the AFL VALVE. I'm replacing my valve body right now and making video in the process, there are few videos on KZbin, some with transmission out of trucks and only one I found that shows how to do it with tranny still in the truck but it's very long.

[@timmullins5335]

just seen ur video. mine is doing the same thing. did u fix it and if so what was culprit

[@jaychristensen4600]

+Tim Mullins Yes, Torque converter was the issue.

[@timmullins5335]

Thanks appreciate it. Keep making these videos. They really help. Am doing mine right now

[@ericbarnes20091]

Would it rev over three thousand when u got it to sixty five

[@jaychristensen4600]

Not in 4th, yes in third. I tried everything to include a different Valve Body with identical results, So I believe the torque Converter is the only thing left.

[@marcocasillas5023]

thanks for the video I have the same problem I think it's AFL valve need special tool 7 7 754 - TL but the tool costs $300 to the valve body did you find it was something else

[@jayebee5306]

I have a 1998 GMC k2500 with a 4l80E. When I accelerate, right in between gear change my truck jerks or pops forward hard? Any suggestions?

[@jayfam23]

Did you find a solution to this problem ? I have the same problem when shifting 1st-2nd .

[@martinmunoz8384]

did you ever found the problem

[@alexholt5415]

4l80e only has 4 gears that's it not 5

[@bryanst.martin7134]

There are 6 speed versions available.

[@form109]

@@bryanst.martin7134 if it has 6 Gears its not a 4L80E..... the 6 speeds are 6L80 i think.

[@MichaelFlatman]

He means lockup in 4th is like another gear..

[@willkeppel1168]

Its important to pay attention before you make stupid comments.

[@tommavrakos]

mine will get in 4th which is overdrive then shift to 3rd.why

[@jaychristensen4600]

Ive got a new TQ for it, but haven't put it in, it only happens rarely and haven't been driving the truck much. Ill report back when I get to it.

[@jaychristensen4600]

TC sorry, not TQ.

[@exhilarationaccelerationpo9082]

Yup, seems to be running just like My 2000 GMC Savana 4L80EWith one exception, mine isn't shifting back down into 3rd. Disconnecting the Battery for 20 minutes solved my over drive problemand shifting late ...temporarily. -----------------I haven't tried anything below this line YET ------------------- Caution! Caution! Caution! Caution!------------------- At some point there after 20 minutes, the PCM/ECM will need to be reprogramed. kzbin.info/www/bejne/omarZXx_gbmjgac Another Idea is; Removing the Transmission fuse for 20 or more minutes. The 4L80E fuse is located in the engine bay. You're going to look for a giant fuse box. It's covered in plastic and usually pretty close to the battery. On the Silverado, Tahoe, Sierra, Express etc, it's located on the driver's side above the fender.Feb 12, 20184L80E Fuse Location | Drivetrain Resource - 700R4 www.700r4transmissionhq.com/4l80e-fuse-location/ Best Idea is tossing $350.00 at it by; Replacing the Transmission controller with a new one See. www.summitracing.com/parts/tci-30282/applications

[@r.d.ontheroad-1094]

what do you call a lockup, thanks,

[@kylewitteberg2927]

Dumps the torque converter

[@scarface-39]

Kyle Witteberg It actually locks up the torque converter to a solid connection from the engine to the transmission and does away with the fluid connection

[@kevinearles1]

@@scarface-39 If you were driving then how could one tell if the lockup happens?

[@scarface-39]

Big Kev usually at speeds above 45 and transmission warm if you watch the rpms it will shift into overdrive, then you will see a small decrease in rpms maybe 100 or less when torque converter locks up, with your foot steady on the gas you can touch your brake pedal lightly and you will see it unlock with a small increase in rpms.