L99 slips one time per gear when cold

[mjb_baldy]

When I get off work at 6am (60ish degrees), I let car run for a few minutes before pulling out of the parking lot and drive sensible and I notice every time my 3rd to 4 shift slips a little (Rpms jump a little). Well the other morning it was 40 out and I slipped going into 3rd and going into 4th.. I have headers, CAI, and tune from RDP Motorsports and I have very aggressive shifting in S mode and stock shifting in D mode.. I slip in both modes.. Here's the kicker, after the first initial slip I can stop and do it again with no issues. It is only the first time it goes to that gear after sitting for 12 hours. Not sure if it does it other times (after startup) as I live in town and take me about 5min of driving to even get to 4th gear.. Any advice what it could be? After the initial shifts it goes back to shifting strong and stout

[qcman]

That is very strange for sure. I haved a L99 tuned by them as well and mine is pretty aggressive in both modes but S moreso... I would PM Dynosteve (RDP) here and ask him about it if it were my car. He is a great and helpful guy and might be able to offer some insight. Or perhaps give your tune another look see....

When was the last time the tranny fluid was changed as I see the car is a 2010?

[Red2014SS]

Might be low on fluid. I've read a lot of posts from guys claiming their auto was a quart low right from the factory. Might be time to change the fluid and filter. Sounds like once you get going and the fluid gets moving around, the problem goes way.

[flamandj]

Wow! Finally I find somebody with my same issue! This process of starting the car ( cold start up) , letting it warm up( 5 mins) , then put it in drive and when it changes from 3-4 it SLIPS every single time... Now, once it does that initial 3-4 gear change and I stop and got back to 1st gear it does not happen again!

Other issue... Every time I start her up, again cold start, the car makes some weird transmission noises that only happen during the 1-2-3 gear changes... Very mechanical noises... It's done it since new! Please help. I really happy another person has the same issue. The cR is 2014, I baby it, low milleage since it gets used every other week. No tune, just cat back, intake, range.

[Red2014SS]

Originally Posted by flamandj

Wow! Finally I find somebody with my same issue! This process of starting the car ( cold start up) , letting it warm up( 5 mins) , then put it in drive and when it changes from 3-4 it SLIPS every single time... Now, once it does that initial 3-4 gear change and I stop and got back to 1st gear it does not happen again!

Other issue... Every time I start her up, again cold start, the car makes some weird transmission noises that only happen during the 1-2-3 gear changes... Very mechanical noises... It's done it since new! Please help. I really happy another person has the same issue. The cR is 2014, I baby it, low milleage since it gets used every other week. No tune, just cat back, intake, range.

Mine was the same way - very sloppy shifts, occasional noises, etc... then I got it tuned. No problems since then. Get it tuned, you will be amazed at how much better your car runs. It shifts like it's supposed to shift... no more annoying AFM.. no more weird behaviour.. It's really like night and day.

[Moto-Mojo]

Never underestimate the power of a good fluid and filter change when it comes the automatics. Can cure a multitude of problems.

[mjb_baldy]

I am all for changing oil and filter I just didn't want to do that then have to crack it open again because there was a different fix for it.. I'm not concerned that it's a tune issue.. I was hoping maybe a filter issue just wanted confirmation from the pros .

[mjb_baldy]

Also as far as I know it's never been changed 33k miles atm

[Red Jewel RS]

When I had my SS I had the same problem. Mine was stock, no tune and only happened at 1st start up after sitting overnight. It could be low fluid I never looked into that.
My 10 LT didnt do that and my current Camaro doesn't either.

[mjb_baldy]

I will get it changed and let you guys know results

[Jasper]

I had a Grand Prix which did weird things after we got a tranny fluid change. Turns out it was over filled. So yeah, autos can be touchy.

J

[ravensjeff]

Normal driving habits have tranny fluid changed at 100,000 miles. Manual even says it is a difficult procedure just to check it and should be done by a dealer. Low/high fluid levels could cause what you are seeing. Doubt it is the tune. Could be, but doubt it. These cars don't "burn" tranny fluid, so it either came like that (low/high level) from the dealer/mfr or you have a leak.

[mjb_baldy]

No leaks as I park is same spot in garage and at work.. Hope it's the filter

[InFiD3ViL]

Originally Posted by Hawkman42757

I have a 2018 automatic 8 speed Camaro convertible doing the exact same thing. I had the transmision completely flushed with the new GM recommended fluid and filter. Still does it even after that. Not sure where to go next. As mentioned previously, it is only the first thing in the morning when you put it in gear. Never happens again for the rest of the day but guaranteed to happen every morning, first year will slip. It only has 44,000 miles on it. Any ideas?

I think you should make a post in the 6th gen forums on Camaro6.com and see what they have to say. There are enough differences between the 6L80e and the 8 speed that I wouldn't try to compare them.

Besides, I know there are some known TCC issues with the 8 speed that they will certainly know more about this over there.

Good luck