6L90 option for G8- fitting for...for next trans failure

[mi04se1]

According to my parts catalog, the tcm is the same between a 6L80 G8 and a 6L90 CTS-v.

[gr8lover]

According to my parts catalog, the tcm is the same between a 6L80 G8 and a 6L90 CTS-v.

Tehcm and connector is exactly the same... the only reason why you would want to maybe use the G8 Tehcm is for the program in the Tehcm... I am not sure how it would work and if it would identify everything correctly if not flashed properly... that is why by using the G8 Tehcm would be easier overall.... (ps.. I am not a programming guy so I dont know how it would effect the trans if you use the 6L90 tehcm but by using the g8 tehcm it should work well... unless I am missing something on the programming part of it....??) but as for mechanically it is a pure plugnplay...

[mi04se1]

The tcm is the same part number. It wouldnt matter if you use the one the the 6L80, they are the same.

[gr8lover]

Quick update: 6L90 was installed in my car with no issues (temporarily)........ shifter exact same location, everything connects as in 6L80 except for rear mount and driveshaft. Everything clears and there is plenty of room for this to be installed. Only thing I didnt verify was if the pan would work and how much it would hang lower..... looks like everything around it clears but not sure on pan depth yet... I will have to look at the prints to check that. THe rear mount can be easily modified by either making new mount or cutting off two sides, making two extensions, and welding them on....due to the holes being shifted by about 34mm..

In my opinion I would get a new aluminum driveshaft made with slip yoke ... versus modifying current..... (i think would be better option..... new aluminum driveshaft and eliminate the current "tiny" driveshaft where it expands/retracts...) I was going to discuss with Chris at Gforce on when he will make it... .. I am sure he would do this for us in a second when someone actually does it and needs it....

I will add pics tonight or tomorrow..... got to run to a Cinderella/Scorpions concert now...... Good news overall for future mods....

[gr8lover]

The tcm is the same part number. It wouldnt matter if you use the one the the 6L80, they are the same.

thanks for the info.... that makes it easier!!!!

[gr8lover]

I'd still be worried about the tuning end of things. If you frag the Circle D 6l80 you're going to frag the 6l90, too...

Andy

I agree---- the tune is so important that hopefully it will be right... I am happy with Livernois and will stay with them on the tune.... I dont expect the Circle D rebuild will have any issues but just seeing what is possible for those that may want it or need it later on..... including myself. However, with the tune correct and good... the 6L90 is the monster we have been looking for and very easy to get into our cars... in my opinoin...

[VegasNate]

This is great stuff Chuck!! I'm waiting to see if this is a realistic solution for me too.

[Dave Ga]

I wish someone had been this smart months ago! I already paid to have my 6l80 redone and have more trouble already! everybody told me that the 6l90 was not a viable option for us when i broke my tranny the first time. i still think my tune is my main issue but, a6l90 would sure be nice, i am glad guys like you can get this done for the rest of us! keep up the good work!

[Tempest2000]

I'd be curious to see if a 6l90 holds up better than the 6l80... Hurry up someone has to try it out for the rest of us LOL

[Boostpatrol]

I am leaning towards just saying f*ck overdrives for what they really save me in fuel, cause dead cost for me to do a rossler 4l80 is 5k landed here in canada, plus a 1500 dollar controller, plus a driveshaft plus the headache of getting a speed signal to the ecm. Then theres the headache of all the testing of it. The 6l80e/90e will be a constant 1900 dollar uprgrade 2 to 3 times a season and it will still slip. So im likely gonna do a terminator 3 turbo 400 with brake from rossler in the winter.