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Warning to all manual transmission owners that race their cars!

12K views 25 replies 16 participants last post by  pmsteinm 
#1 ·
Welcome to my manual transmission nightmare.

I bought my certified used 2009 CTS-V about a year ago with 22,000 miles. Car was perfect, no mechanical issues whatsoever. About 3 months later I added a ported snout, 2.55 pulley, intake, exhaust, and D3 suspension. Car dynoed @ 525 rwhp.

In August I took the car to Auto Club Speedway for a track day with Speedventures and D3. After boiling the brake fluid and overheating the differential my day was done after 3 25 minute sessions.

I replaced the brake fluid with high temp stuff, built a diff cooler, and added some r888 tires for my next go round @ Auto Club for the first round of the Cadillac racing series in February.

Through the first 2 sessions car performs great and a shave 3 seconds off my times from August. During the third session I begin to hear a faint whine during acceleration in 1st through 3rd gear, which progressively gets worse throughout the rest of the day. There are no symptoms associated with the noise, transmission shifts perfect, no clutch issues, just the loud whine.

So Monday after the track day I put the car on the lift, drain the trans fluid through a painter's filter looking for any signs of internal damage. Maybe I chunked a tooth on gear during a bad downshift. After filtering the fluid twice, I discover no metal in any of the fluid. So I decided to fill the trans with some Royal Purple Syncromesh to see if the noise gets better.... Noise was improved but I was still concerned. I called D&D transmission (they built the trans' for the CTS_VR's) and was told the noise was probably a damaged input shaft, FML!

I end up pulling the trans to have a look inside for myself, and here is what I found.
Input shaft and cluster gear overheated and scuffed the gears. Notice the discoloration and hash marks on the contact pattern.
View attachment 88309
From what I have learned this can only happen from a lack of lubrication or a break down of the fluid itself. I never received a transmission overheat message in the DIC. My only theory is that during the banked turns 1 & 2 of the NASCAR oval in 5th gear @ 130+ Mph, there is enough G-force to pull the fluid away from the junction of the input and cluster gears, causing the damage.

Cost to repair,
New Input shaft $340.00 (only made by GM)
New Cluster gear (actually 4 gears machined onto 1 shaft) $550.00 (only made by GM)
R&R transmission $500.00
A week and a half of my time.... priceless

I would have tried to warranty the car but I wasn't willing to take the chance and have them blame it on the supercharger pulley and triple the cost of the repair.

Unlike the previous 6 speeds, the tr6060 in the CTS-V is a very strong trans, and there are no upgrade parts other than bronze shift fork pads (Tick performance). The factory transmission cooler (located inside the radiator) is woefully inadequate for racing IMHO, so I have added a Setrab cooler to the front of the car and replaced the factory lines with -6 braided line. This adds about a quart of fluid capacity too.

It's also a good idea to fill the trans with the car running, that way the pump is filling the lines and trans cooler and you can get an accurate fill.

I will have the car put back together and @ Chuckwalla raceway on the 24th and I will report back after that.
 
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#4 ·
I'll have to look at the service manual but I don't remember seeing any mention of the transmission cooler when doing the fluid change procedure. It just says to fill until the fluid comes out of the fill hole. Of course the book also didn't have the drain plug quite right: it said to remove the temp sensor and drain from there instead of using the actual drain plug.
 
#8 ·
The trans has an internal pump run off the front of the cluster gear. The pump sucks fluid from an elongated pickup tube (changed from the earlier tr6060's, to prevent oil starvation) out of the passenger side of the transmission through a hard line up into the driver side of the radiator (like an old car with an automatic transmission) then back to the driver's side of the transmission up near the junction of the input shaft and cluster gear.

The factory service manual is also incorrect when decribing the removal of the shifter asembly. It shows something completely different than what is actually in the car.

I also disagree that the car is not designed to handle what I am throwing at. This is my third V-series car (2005 CTS-V, 2006 STS-V, 2009 CTS-V) and from the very beginning they has been marketed as dual purpose cars. Cadillac's Nurburgring record is a good example. I've also been under that car in person and is was stock other than the diff cooler and rotors. I'm not professionally racing my car, just running it as fast and hard as I see fit. I understand the car has limitations, and I have already had to pour my money and knowledge into the car to fix what GM promised from the beginning. Anyone remember the "track package" that was going to offered with the diff cooler, or the 2pc rotors... None of us needed yellow brakes, sapele trim or sparkly paint, and even though they are awesome they don't make the car perform any better

On a lighter note the car is put back together and the transmission is working great. The only issue I ran into was the brass fork pads are much larger than the factory plastic ones (about .005-.010 each) If you don't hand file each one to slide effortlessly into the blocker rings, it will change the spacing on the shift rail by .040-.050 and the shifter won't be able to spring load back into neutral. It will just stick in between 1-2 or 3-4, or 5-6 never returning to center. On the early 6 speeds (t56) they slid into the rings with no modification.

Here are some pointers on removing the transmission that the manual's don't mention. It's all made more difficult because the bellhousing no longer unbolts from the transmission externally. The bolts are inside the bellhousing and it serves as the front plate of the trans.

1: Back out all 6 of the front subframe bolts about 1-1.5", leaving 1/2 of the remaining thread engaged. Similar to procedure for installing the D3 front swaybar. This lowers the front of the bellhousing to clear the firewall better, and makes lining everything up easier come installation time. At the factory they install the motor and trans bolted to the subframe from underneath the body.

2: Remove the 2 8mm bolts that hold the transmission cooler lines to the oil pan. This will allow the lines to be pushed out of the way when lowering the transmission.

3. The trans has to be cocked to a 15-30 degree angle toward the passenger side to slide in between the factory catalytic converters.

4. You don't have to remove the driveshaft from the car, just disconnect it from the trans leave it attached to the rear end.

5. The top bellhousing bolt is only accessible from the engine compartment, reaching behind the blower

6. When reinstalling the trans, once the input shaft is meshed with the clutch the trans won't completely seat against the engine, there will be a 1/2" gap, but installing the bolts and going around in a star pattern will pull the trans flush to the block.

7. If you plan on going to an external trans cooler, the factory fittings can be replaced with -6 male ports. The threads in the trans are 9/16- 18 SAE.

These cars were meant to be driven, and it's a shame that many, and I mean many of them will never be allowed by there owners to show what they are capable of. Lets hope the more we push these cars the more good information will flood this community.
 
#7 ·
Must be a manual thing. I got symptoms of oil starvation after 2-3 consecutive wot pulls at higher speed....Must be why the ZL1 is getting a higher flowing pump. I'm hoping that a higher flowing oil filter will take care of it but the only thing that will prob work 100% is a baffled oil pan. I would have never thought that g-forces would have been the downfall of the manual V's
 
#12 ·
Yes, but Vs are available with yellow brakes, sapele trim, sparkly paint, A/C, cruise control, power windows and locks, and all this other BS that doesn't serve to, um, make the cars any quicker...
 
#13 ·
Yup, it's a performance luxury vehicle. We all want to it to excel at both. That's why we all bought them. In any case, the OP identified a problem operating the vehicle in an environment where it could reasonably be expected to function without major failures. He put up a detailed explanation with pics, so I think a more useful conversation would be to try to figure out exactly what happened in this case, if anyone else of the multiple Vs running this course that day has experienced similar symptoms, and what can be done to prevent this in the future, so more of us can participate in these events with some peace of mind.
 
#15 · (Edited)
Yup, it's a performance luxury vehicle...
I couldn't agree more. But if you're going to mod it, use up margin that the factory left in there, and then race it, it's going to break. Yes they ran it at the Nordschleife, but it wasn't hour after hour at full pace. All the cars run at the CTS-V events like Montecello, etc. were bone stock with the exception of the 2-piece rotors and diff cooler kits for reliability and longevity.
 
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#16 ·
I noticed the wrong pictures in the service manual too: they are clearly pictures of the 04-07 CTS-V. It makes me wonder if the whole transmission section is really for the T56 and never got updated.

Regarding filling the transmission, I tried with the engine running and that doesn't work: fluid pours out of the fill hole. I filled until it dribbled out with the engine off and that seems to be correct. The factory fill was the same. And based on where the cooler lines are as you fill the transmission it should fill most of the cooler lines. I did notice the service manual says the capacity is 3.65QT, the owner's manual says 4 (which is what it took to fill).
 
#19 ·
Personally, I don't have a V, but I appreciate this type of thread waaaay more than "What type of wheel should I get?" Thorough and well written.
 
#22 ·
Some people. :banghead:

FlyingV thanks for this thread. I've taken out the tranny in my Camaro SS so many times I can't stand it anymore. Tips like the ones you gave are very much appreciated. I try and learn from other peoples mistakes and experiences. Hopefully I won't have to pull the tranny on this car ever. I'm getting to old to be laying on a garage floor.
 
#26 ·
I tried the best I could...I came up with roughly 3.5, but there was some major spillage: after you've proven you can loosen the fill plug, put it back in before draining...otherwise the fluid shoots out of the drain plug and hits the exhaust, misses your drain pan, etc, etc.
 
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