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6L80E slips in first and second?

19K views 41 replies 17 participants last post by  deb0650 
#1 ·
At WOT it feels like the transmission slips for about a second at the top of first, and then again at the top of second.

Fluid level is correct via the GM fill / check procedure.

Any tips or common areas I should look at when it goes in for repair?
 
#2 ·
How many miles on the trans?
Mine did that for a bit when I was around 95k miles. I had a deep camaro pan and widemouth filter put on at 100k service. This seemed to be a pretty common upgrade for other board members. Haven't had that feeling since. I can't be sure if it was just old fluid or the pan/filter that make the difference, probably both. Others may know more.
 
#6 ·
115K on the car, I bought it used, so I assume there is 115K on the trans. Maybe I'll try the deep pan and filter before taking it to the dealer.
 
#3 ·
The internal solenoids maybe shot. I had an estimate of $1,000 to get it fixed I just went out and bought a remanufacture transmission for $3000 with a 3 year warranty. I know it's a lot of money but I was thinking about the warranty.

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#4 ·
LOTS of variables here.

Fluid level incorrect
Bad seals
Burnt clutches
Bad trans tune
etc

Have it checked out by a professional
 
#7 ·
The fluid level is correct, and it does it on the stock tune or the modified tune; but all the other variables you mentioned are in play.

It's under warranty, I'll shoot it by the dealer and see what happens.
 
#9 ·
Few ideas.


I know you have the stock stall, but these transmissions are very sensitive to fluid levels. When doing a stall we always put in an extra quart and it seems to help. If not, some cars experience a weird slipping feeling on occasion.

Flares...... At the top of second(going into third) they are also very susceptible to flaring with some tunes(I've seen a few do it with stock tunes in certain settings). You did say it is now doing it with the stock tune, though, right?


I'd add fluid even if it shows that its coming out when hot idle in park and if not good bring it in for repair since you're under warranty!
 
#16 ·
In my car? Out of curiosity, how would you know that?
 
#18 ·
The 6l80e is such a pile. I am finally giving up on it and going with a TH400. Now that I have a nice DD, I am making the change.
 
#21 ·
I have the car back now. The dealer fixed several things under warranty; the oil pan gasket, the rear main seal, did the control arm TSB, etc...

However, they did not touch the transmission other than removing it to replace the rear engine cover / rear main seal.

The warranty administrator told the tech flat out that trying to get the transmission done under warranty would be denied, if we tried to do it right now. The warranty on the car is only a month or two old, and the warranty company would claim that the transmission problem was pre-existing, and therefore not covered under the aftermarket warranty.

The warranty admin recommended I just deal with it until the transmission fails entirely, or until there has been some time and mileage put on the car. Time and mileage would help the warranty admin get the powers that be to approve the transmission repair without falling back on the the "pre-existing condition" excuse.

So, while the car is running wonderfully, the trans is still acting wonky. I'll update this thread as things develop.
 
#24 ·
You are correct, after reading the service contract again, I believe the transmission issue would be covered had I not inadvertently fixed it.

Earlier today, out of frustration, I decided to overfill the transmission. I put on my lift, let it run until the trans was at about 40 deg c, left it running, raised it up, removed the fill plug and trans fluid dribbled out. I figured that meant my fluid level was pretty close to where GM wants it, give or take a little.

From there, I let it drain while the engine was running until it was just a drip (which should be GM's desired level if I understand everything correctly) - then I added a full quart and went for a drive. The problem was lessened noticeably. And I could make the problem go away entirely if I tested the trans while going downhill. Fluid being pulled towards the rear and uncovering the pick up during acceleration seems to be my problem.

Back home, back on the lift, I put in another 1/2 quart. Off the lift, out the driveway, to the undisclosed test track by my house... The transmission performed as it should, no slipping, burbling, flares, etc... Just what a stock transmission should do. Shift gears, no drama.

I am sorry for everyone that I've engaged on this issue, and the time ya'll have wasted trying to help. In the end, another 1.5 qts of fluid took care of it.
 
#26 ·
Thanks for posting your findings. I still haven't got my Camaro pan installed yet, but when I do I will be adding extra fluid. My tranny seems to be working much better since the weather has warmed up. It might have been a combination of lowish fluid and cold fluid when I experienced my flares.
 
#27 ·
The fluid expands some when it gets hot, which would raise the fluid level a bit. If it works better when warm, I would suspect the fluid level.

That being said, looking at this thread objectively, I'm the last person you should listen to, lol. I've been dinking with mine for months, had it to a GM dealer, swallowed the lie about the pre-existing condition invalidating the warranty, and only through dumb luck did I solve my issue.
 
#28 ·
I found that filling the trans COLD gives the right level of overfill, just enough to stop WOT slipping. With the Cortex setting at 50% it will chip third gear
 
#29 ·
How exactly did you fill it while cold? Already have car level and let it sit overnight, then turn it on and immediately go through gears quickly. Leave it in drove. Remove fill and drain plug, then add fluid until it starts to dribble. Put plugs back...?

So you didn't have to add any extra after at all?

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#30 ·
just a fyi,, I installed a jannetty 6l80e trans tube ,, he has them in stock ,, its really the way to go,,
 
#32 ·
Did you have any codes come up as a result of the trans slipping from 1 to 2. I have codes P0989 & P0872. Just wondering if the overfilling would be the fix.??
The reason I say that I did a filter change checked fluid per procedure was 'full' than checked a few weeks later was low added fluid to 'full' level and about a half quart extra still have issue.
 
#36 ·
I had no codes. Mine took about 1.5 quarts over full for the issue to go away.
 
#33 ·
Old thread, but I suppose a refresh doesn't hurt.

I'm not trying to step on anybody's toes, but I think there is a general misnomer on the internet in many of these forums that the problem goes away just because it needed more fluid. They talk about foaming to scare the average DIYer away from touching it. What they DON'T talk about is why the slipping sometimes goes away.

Fluid pressure increase will smooth out the shifts. It's just masking the actual problem.

Some people get lucky and sell the car before the transmission is wrecked. Others post threads asking why they fried their transmission. ;)

Which one will you be?

Be the one that goes to the shop, and even takes it for a second opinion just to be sure. Be the guy that has his money saved up for the job and fixes it right. ;)
 
#34 ·
"silly0582" >>>>> Those 2 codes are saying that the transmission is detecting that #3 an #5 TFP (transmission fluid pressure) switches are not functioning correctly. They say the switches *can* get contaminated with debris, causing them to malfunction. They say GM (using their scan computer) has a dedicated test procedure designed to cycle the solenoids an valves (in the control solenoid valve assembly), in an attempt to dislodge debris to free up the circuit. If no success or switch failure is found, they say you would have to replace the Solenoid Valve/TCM assembly.
 
#39 ·
I was part of this thread awhile back and had the shift flare at WOT. After putting it off several months I finally jacked the front of my car up and removed the fill plug on top of the transmission and pumped 3/4 of a quart in. I never started the car and cycled the tranny before adding more fluid. Took it out for a test drive, let it warm up for several miles then went WOT from a stop and had no more shift flare. Shifts were firm and had some chirps from 1st to 2nd and 2nd to 3rd. I can't say this isn't a bandaid, but it worked for me and has been working perfectly for 5,000 miles.
 
#42 ·
In a couple weeks I'll be pulling my 6L80 and swapping a TR6060. Trans is great and only has 52K. I'll give you a good price. :)
 
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