GM 6 speed autos - 6L80E/6L90E folks in here

[BonzoHansen]

You guys with trucks and cars with GM 6 speed autos, how do you like the transmissions? How do they shift? Do they hunt for gears? Do they shift too much? Are the gear spreads too wide? What are the reports on durability?

I'm especially looking to hear from you G8 and 2010 Camaro guys.

Please, no hearsay unless you at least have some links to what you've heard.

[BigAls87Z28]

DUPED ME!
I have a 6T45E...totaly different set up, but if the programing is the same, then its alright.
The manual shifting is pretty quick. Not DSG fast, but quick.
I have driven the G8 GT and CTS, both the transmissions seem to shift very smooth. Cant say I can recall much based on downshifting or skipping gears. The 6L80E is a sweet unit.
Are you thinking what Im thinking big fella?

[BonzoHansen]

I'm just gathering data.

[Featherburner]

Well Scott, I'm generally pleased with the 6L80E. With the factory tuning of the G8 the shifts are very smooth under normal around town driving. When pushed, WOT shifts are less than impressive due to the factory tune with 100% torque management. It feels like it falls flat on its face between shifts. It is my understanding this can be cured with a tune to deliver crisp "tire chirping" shifts. Maybe Brian can expand on this with his firsthand knowledge. I don't feel that it hunts or shifts too much. It seems to find the right gear when downshifting while accelerating. The gear spacing is spot on. First gear is 4.03 to 1 so even with a conservative rear gear it will get out of the hole nicely. The G8 has 2.92 from the factory and most guys that are changing rear gears are going with 3.27. As for the durability issue, they seem to be a durable piece. I have read about two that have given up the ghost. Both were running boost. One had a twin turbo set up with an excess of 700 RWHP and lasted 18000 miles with many drag strip passes, with the ET in the 10.70 range. The other one I've read about was supercharged with a magnuson supercharger making an excess of 650 RWHP. His problem was slipping between shifts. The only thing they had in common was they were tuned by the same company so that may have been a contributing factor.(or, just massive HP) If you are looking to put the L76/6L80E or L99/6L80E combo in your vent window car, I think you'll be more than please.

[Stevoone]

Haven't seen too much on the RWD yet. On the FWD trans I've heard of shifting complaints, they usually say the trans feels like it shifts too much or that it feels too busy. The trans will engage TCC in 3rd 4th 5th and 6th gear so that may add to the shifting complaints. Haven't had any problems with them yet, but we don't usually get too much trans work anyway.

I took 2 of them apart and their really easy. When I was at GM training the instructor was saying that it was a shared design between GM and Ford. The pictures of the GM trans and the Ford trans look identical.

[Featherburner]

Scott, I added my 2 cents.

[BonzoHansen]

Thanks.

[Blackbirdws6]

I have had positive experience with the 6spd auto in my G8. The only thing I didn't like about it was the factory programming. Shifts were sometimes slow and the tap up/tap down feature was too sluggish to give you a decent manual/auto trans feel.

I never had any issues with it hunting for gears but if you wanted something drastic to happen, it was very dependant on how deliberate you were with the throttle. This wasn't a glaring issue but you had to really provoke the car for a nice 6th gear to 2nd or 3rd downshift.

I've modified all of these parameters within HPTuners and have gotten quite good with the trans tuning which is very very complex. Durability wise, my first hand experience is that I haven't had any issues. I'm not a track rat but I have over 30 passes on the car banging gears and have noticed no degredation in how the trans runs or functions. A lot of the stock tuning lag, primarily when shifting at WOT, is due to torque management. People are able to now tailor how aggressive tq mgt is at different rpm and throttle levels. If you are just driving around like a normal person, the stock tuning is fine. I just wanted a crisper and more deliberate feel.

Guys are strapping boost to G8s and the trans seems to be able to hold it. Guys are still using the stock trans and already in the deep 11s if not high tens, granted the only mod I'm aware of is a higher stall converter. I'm not sure how long the trans will last in these configurations but they seem to be holding up.