Is the A6 auto tranny in our Vettes exclusive to them only? I searched, but could not find an answer.

 

In G8s/Camaros/Suvs/Trucks/ 6L90E in CTSV i think that may cover it.

 

OK thanks.

 

It's exclusive in that it's designed to bolt to the torque tube instead of to a bellhousing in the front and to bolt to a differential instead of a drive shaft in the rear.

the internals may be the same as other transmissions but the front and rear of the case has to be different due to the location of the transmission.

 

 

what shane said.... and only a handful of people know how to properly tune them

 

They are pretty tough, I have over 140,000 miles on mine in my 07. It out lived the diff.

 

The 6L80 transmission is a modular transmission in that the transmission case is the same for all models/applications. The torque converter housing (what you're calling the bellhousing) bolts to the front of the transmission case and is model dependent. The case extension bolts to the rear of the transmission case and is also model dependent. The only other things model dependent are the output shaft, transmission fluid pan, and the oil level check plug. The C6/XLR uses a very short case extension (maybe 1½"???) with a long output shaft and the differential bolts directly to the case extension. Other applications use a long case extension (maybe 7"-8"???) with a short output shaft and the driveshaft yoke slips in the case extension which also a yoke bushing and seal.

However, the front and rear of all 6L80 transmission cases are identical and of course the internals are the same except for the output shaft. I can post up some drawings/parts list if anybody is that curious.

 

The Camaro ZL1 gets the 6L90. The 6L90 is in certain trucks also, I have one in my '07 Silverado HD 3500 dually. GM doesn't use the "E" on the 6L80/6L90 because there are no mechanical versions. You'll find plenty of non-GM websites where the "E" is there but GM does not use it in any of their manuals, press releases, or sales literature.

 

The question of differences between the 6L80 and 6L90 has come up often. From what I've heard, the case length is the reason the 6L90 won't swap into the C6. Are the bolt patterns and related shaft centers the same, as I would suspect they are? Do the CTS/V and Camaro ZL1 compensate for the length with the driveshaft? If so, wouldn't shortening the C6 torque tube work equally as well?

 

Yes, the 6L90 is 35mm longer than the 6L80 but they share 75% of the internal parts. The 6L90 has increased capacity due to two more pinions in the input planetary carrier for a total of six, wider pinions in the output compound planetary carrier, and extra clutch plates/frictions in some of the clutch packs. The extra length of the 6L90 is due to the wider gears in the output compound planetary carrier due to the nature of the gearset...there simply wasn't enough room to add more pinions.




You can see the four pinions in the 6L80 input carrier (pc 52) and how there's plenty of room for two more. However, if you look at the output carrier (pc 68) with the compound planetary gearset, you can see the forward and aft pinion gears are on the same shaft (they are free to rotate independently from each other) but the aft gearset has an extra gear driven/driving the pinion. There are three pairs of those gears for a total of six gears in the aft planetary gearset...there simply wasn't any room to add two more pairs/four gears to the aft planetary gearset so they had to go with wider teeth. You can see the splines on pc 61 (1-2-3-4 Clutch Hub Assembly) and pc 64 (2-6, 3-5, and Reverse Clutch Hub Assembly) which engage the sun gears in the output carrier compound gearsets (pc 61 goes through the hollow center of pc 64). Pc 61 engages the sun gear for the aft planetary gearset and pc 64 engages the sungear for the forward planetary gearset. You can also see the two different output shaft assemblies (pc 70) for the different models...the long shaft is for the C6/XLR and the short shaft is for all others.



In this one, you can see the three different torque converter housings (pc 70) and the different case extensions (pc 15 for the C6/XLR and pc 34 for all others). But the transmission cases are all the same for the 6L80. So yes, bolt patterns are the same, the shaft center is the same (there is only one shaft center), and the CTSV/ZL1 compensate by a shorter driveshaft. You could shorten the C6 torque tube and that would certainly compensate for the extra length but there are three dimensions to the transmission case and you're moving the largest diameter (the torque converter housing) forward so the floorpan would need to have some extensive "massaging". The shortening of the torque tube would be the easy part...cut 35mm off and weld back together.