Cadillac CTS-V Transmission Major Issue

[Crowley]

Originally Posted by jthurik

the CTS-V does not have the same tranny as the Camaro or the Vette the tranny is the CTS-v is a 6L90 not a 80

The ZL1 will have the 6L90 though correct? I hope they have upgraded this tranny in some way. I know I have heard complaints (magazines and drivers) about the auto tranny and daily driving and issues that they have had with it.

Crowley

[v6sonoma]

Originally Posted by jthurik

the CTS-V does not have the same tranny as the Camaro or the Vette the tranny is the CTS-v is a 6L90 not a 80

Or a Tremec.

[jthurik]

Originally Posted by Crowley

The ZL1 will have the 6L90 though correct? I hope they have upgraded this tranny in some way. I know I have heard complaints (magazines and drivers) about the auto tranny and daily driving and issues that they have had with it.

Crowley

Nope ZL1 will have a upgraded 80

[woodstock]

Originally Posted by v6sonoma

Or a Tremec.

Tremec 6060 six speed in the Corvette ZR1

[djsnoflake]

I see the problem in the first few sentences.

"First one's about a friend of mine whos a street racer."

He's lucky he has enough brain cells to breathe without needing a ventillator.

[Andy@Livernois]

the V does not have a weak trans, manual, or auto...

we have made 660 at the tire with a stock blower on an auto, with numerous track passes and it is his daily driver.

if you don't know how to tune the 6-speed auto, you can break it stock.

[Judge]

Originally Posted by ckaram

It really depends on how much power they added, how they abused it, what kind of tires were they running, etc.

our friend had it tuned to over 600 horses

Originally Posted by TheCaptain

Also, what year of V? Gen 1 or Gen 2?
Besides, let's all just upgrade the engine, and never worry about drive train and brake upgrades...

its a 2010 model, so i think its the 2nd gen?

Originally Posted by DietCoke

Same trans as the camaro, with one extra gear in the planetaries (5 vs 4). It's unsurprising it doesn't hold up under the extra power a modded one makes, plus the cts-v's weight.

More details on this please..

Originally Posted by Nine Ball

The automatic trans also has its own computer. Savvy tuners know how to tweak this for quicker shifts, more firmness, etc... Some custom tuners don't know what they are doing and could actually cause the trans to fail just from a bad tune. My '09 CTS-V is at 550 rwhp and has had zero trans issues.

Mmm.. interesting, i dont know much about transmissions..
but i know for a fact that cadillac V class are supposed to be top notch cars that can handle under pressure, so it might as well be the tune?

Originally Posted by djsnoflake

I see the problem in the first few sentences.

"First one's about a friend of mine whos a street racer."

He's lucky he has enough brain cells to breathe without needing a ventillator.

Easy...Some Of Us Are Street Racers Here

Originally Posted by Andy@Livernois

the V does not have a weak trans, manual, or auto...

we have made 660 at the tire with a stock blower on an auto, with numerous track passes and it is his daily driver.

if you don't know how to tune the 6-speed auto, you can break it stock.

more info please

[TheCaptain]

Originally Posted by djsnoflake

I see the problem in the first few sentences.

"First one's about a friend of mine whos a street racer."

He's lucky he has enough brain cells to breathe without needing a ventillator.

LOL!

[djsnoflake]

Sorry to sound like a D bag, but if you are a street racer, you're retarded. Take it to the track where the grown ups play and leave the street racing to Vin Diesel

[SC2150]

9Ball & Andy@livernoise are right on. Any tuner worth his salt will tweak the trans as well. Failures are rare. DietCoke is right on as well. Knows what he is talking about.

[DietCoke]

Judge I don't know how to give you more info then I did. I will redact my previous post to edit this in though, the 6l90 has TWO more planetary gears then the 6l80 (6 vs 4), I was thinking of the 4l90 vs 80 (which is 5 vs 4)

From GM

The Hydra-Matic 6L90 is six-speed automatic transmission for rear- and four-wheel-drive trucks, designed with modular flexibility and compatibility with advanced electronic controls. It is a heavy-duty version of the 6L80 six-speed automatic, with a strengthened input gearset which has two additional pinion (planetary) gears for six total, and a strengthened output gearset, that uses wider gears than the 6L80. The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the 6L90 is 35mm longer than the 6L80 case. (assuming for the extra meat on the output gearset)



Unfortunately for us car guys, it's not the gearsets that are failing most often, but rather the torque and rpm we turn is killing the clutches. The 6Ls are clutch operated, and not band operated like the 4Ls, which is part of what is giving builders issues at the moment as while the clutch mechanism for gearshifting is more precise, it isn't nearly as strong.

[thePill]

The Hydra-matic 6L90 used in the CTS-V and the ZL1 is probably one of the best automatic transmissions for the price associated in those applications. This doesn't mean that there will be zero issues with them and the lack there of are probably due to the total amount that are actually produced and sold.

GM rated the CTS-V's 6L90 at exactly the torque and curb weight of that vehicle, any additional weight or torque is in fact "pushing the limits" of the transmissions rating of 551lb ft of torque at 4250lbs. This doesn't mean the transmission will instantly break after that, remember the GVWR of the CTS-V is about 5200lbs so the transmission should be capable of about 700lb ft at the actual curb weight... Which is why there were no adjustments made for the CTS-V wagon because the curb weight and GVWR was within 250lbs of the CTS-V coupe. The ZL1 on the other hand needed stronger output shafts and rear housing to accommodate the extra 5 torque even though the ZL1 is about 35lbs lighter than the CTS-V coupe (automatic weights pending of course). The 6L90 is a massive transmission, it weighs 209lbs in the CTS-V so it is about 25-30lbs heavier than the TR6060 MG9.

Think of a transmission as a referee in a match between "Force" (engine torque) and "Resistance" (weight with traction being a resistance modifier). No two matches are the same even though the conflicting participants remain constant. In most cases, the clutch, drive shaft, universals and countless other things in relationship to the transmission are made to give before the more costly internals of the transmission do. If there is in fact an internal issue then it could be a compound issue with that particular transmission that caused the failure.

[radz28]

Originally Posted by thePill

The Hydra-matic 6L90 used in the CTS-V and the ZL1 is probably one of the best automatic transmissions for the price associated in those applications. This doesn't mean that there will be zero issues with them and the lack there of are probably due to the total amount that are actually produced and sold.

GM rated the CTS-V's 6L90 at exactly the torque and curb weight of that vehicle, any additional weight or torque is in fact "pushing the limits" of the transmissions rating of 551lb ft of torque at 4250lbs. This doesn't mean the transmission will instantly break after that, remember the GVWR of the CTS-V is about 5200lbs so the transmission should be capable of about 700lb ft at the actual curb weight... Which is why there were no adjustments made for the CTS-V wagon because the curb weight and GVWR was within 250lbs of the CTS-V coupe. The ZL1 on the other hand needed stronger output shafts and rear housing to accommodate the extra 5 torque even though the ZL1 is about 35lbs lighter than the CTS-V coupe (automatic weights pending of course). The 6L90 is a massive transmission, it weighs 209lbs in the CTS-V so it is about 25-30lbs heavier than the TR6060 MG9.

Think of a transmission as a referee in a match between "Force" (engine torque) and "Resistance" (weight with traction being a resistance modifier). No two matches are the same even though the conflicting participants remain constant. In most cases, the clutch, drive shaft, universals and countless other things in relationship to the transmission are made to give before the more costly internals of the transmission do. If there is in fact an internal issue then it could be a compound issue with that particular transmission that caused the failure.

Excellent post

Thanks for the technical data, too, guys!!!

[TheCaptain]

Good physics lesson Pill! Teach it to the masses!