Case Study: Cadillac CTS-V, Performance 6L80, 6L90, 6L95 Transmission Problems


	Dave Riccio, Owner/Technician

By Dave Riccio, ASE Certified Technician, Owner of Tri-City Transmission & Auto Repair, Co-host of Bumper to Bumper Radio

CASE STUDY: 2009 Cadillac CTS-V

Custom 6L80E / 6L90E Transmission, Built for 900 Horsepower

6L80, 6L90, 6L95

This customer slowly upgraded his Cadillac CTS-V to be a "Sleeper". He entered the sliding scale of how big do you want to go? In this process, at the race track, he hydrolocked his motor as a result of a failed intercooler. As the snowball rolls, he decided he was going to go big, instead of go home, when it came to fixing the motor. His thoughts, "You only live once, so what the hell!!" Needless to say, he had the motor tweaked and peaked till he had 889 rear wheel horsepower and 904 pound feet of torque. This came courtesy of a Magnuson Heartbeat TVS2300, forged internals and flex fuel. Courtesy may not be the right word as it sounded expensive to us. Regardless of the price of the motor, the transmission became the weak link and within a few passes at the track, the transmission started to slip with the new motor. Such disappointment after dropping all the cash at the motor!!

So, our customer researched his options having heard the 6L wouldn't hold up to that kind of torque and horsepower. Some suggested that he convert the transmission to the older four speed 4L80E. He wasn't crazy about that idea and when we initially spoke, neither were we. He loved to take this car to the race track, but for all intents and purposes, the Caddy was not a trailer queen and still a daily driver. We let this customer know we could custom build his 6L transmission to withstand the abuse of his horsepower compulsion. Well, the jury is in and after dozens of 10 second passes, he is not disappointed. The beauty of this car is that he still loves taking it to the office Monday morning. As the snowball rolls, still more tweaking and peaking on the horizon. He intends to break into the 9's.

Transmission Background Information:

This GM transmission replaced its predecessors, 4L60E and 4L80E. We feel it is a good transmission. We have built them up not only for 1/4 mile applications but off road trucks and your everyday soccer mom Suburban. We have found that you can spend all kinds of dough on hype from some transmission builders. We call it sparkle dust. We don't see hard part failure with this transmission as much as we see clutch failures. There are plenty of billet hard parts available to drive the price up, unfortunately, you just start chasing the next weakest link. We utilize what we have found to work, the right mix of frictions and valve body upgrades. We generally run stock programming, however, if you're looking for the extra 10ths of seconds we recommend you work with somebody who knows the art of making your match up of components seamless.

The advantage of local transmission remanufacturing

The tendency for gear heads sometimes is to chase the sparkle dust online. I know this personally as a self proclaimed gear head. When whatever latest bolt on product I bought online finally showed up in the mail, sometimes it was as advertised and sometimes it wasn't. Purchasing transmissions online can be a problem. This is especially true when there is a problem. If you're running high horsepower applications, the unexpected can pop up and you will want local support. Fundamentally with purchasing transmissions online, there is too much break up of responsibility between the installer, the driver, programmer and the transmission remanufacturer. With our custom remanufacturing process, you are able to be hands on through the process and see your transmission disassembled with the transmission bench at your fingertips - something unavailable online. Customers are welcome to be a part of the process if they are interested.

We have commonly built this transmission for Cadillac CTS - V, Cadillac Escalade, Camaro ZL1, Hummer H2, Corvettes along with Silverado pickups. From stock performance to just north of 1,000 HP.