TR6060 MAIN (OUTPUT) SHAFT FAILURE ANALYSIS

[mwt18]

Background:
On Saturday 5/7/2011, during a hard second gear shift, my transmission output shaft broke. I had the car towed to the nearest dealership. When the dealership opened on Monday, 5/9/2011, they called to tell me that they would look at it and get back to me later that day. The following day, they called back to tell me that they looked at it and believe that it looked to them like the transmission shaft was indeed broken, but they didn’t have a transmission tech, so I needed to have the car towed to another dealership. This seemed odd to me, and I wasn’t sure about what to do at this point, so I called GM Customer Assistance. Customer assistance was very helpful and helped me arrange to have the car towed to another dealership. The following day (Wednesday, 5/11/2011) the service manager at this dealership called me to tell me that they had the car in the shop and they had confirmed that the output shaft was broken and that they just got through taking pictures. I asked them what kind of pictures and the guy told me, "We had to take a snapshot of your engine computer and send it to GM along with pictures of your supercharger and other modifications." He told me that they should get a decision from GM in a day or two as to whether or not the repairs will be covered under warranty. On Friday, 5/13/2011, the dealership called me back to inform me that the GM was not going to warranty the repairs due to the modifications done to the car. I told him that I had been looking into this issue and that the transmission output shaft in the early builds are known to be defective and that the failure was not caused by modifications. He told me that I would have to call GM. They would not get involved and had to do what GM told them to do. At this point, I called the GM executive level assistance. This lady (Jeanne Crawford) was extremely rude and after about a week of 'investigation' she finally told me that the warranty was void because of modifications done to the car. I went to the dealership the next day (5/18) and picked up the car from the dealership and hauled it to an independent transmission shop. They ordered a new transmission through their GM parts distributor on 5/25 and replaced the defective transmission on 5/28. I paid for all this out of my pocket. I've filed a dispute with the BBB seeking reimbursement. The arbitration hearing is currently set for 6/20.

In the meantime, I've arranged to have a failure analysis performed to determine the root cause of the failure. Based on pictures I seen other early 2010 M6 SS cars with the same problem, it is obvious that my main shaft failed the same way as all the others did. So, if your main shaft fails and you have a VIN <25,000, here's why:


6/12/11 UPDATE: Much more data has been gathered. I will post it after all legal matters are handled.

If you experience output shaft failure, please take a picture of your METAL transmission tag and post it here.

There are 2 tags. (1):A sticker located on top of the transmission and (2): A metal tag attached to the transmission by a bolt.
The metal tag is accessible with the transmission still in the car and is the tag with the info about when the transmission was made.

Here are the locations of the tags:




Here are the tags from my defective unit:





This is the tag from my new unit (note the different Tremec part number (TUET10860) compared to the defective unit (TUET10150)):



This is the tag on the side of the box. This was the direct replacement from a Chevrolet Dealership. They ordered this part using my VIN.



Another tag on box showing GM part number:



TTC (the manufacturer of TREMEC transmissions) provides the failure analysis guide linked below. The bulletin is focused on the failure modes resulting from abuse and/or neglect. Every issue described in the bulletin assumes no manufacturing defect, so it does not really pertain to this analysis. However, it could prove useful to those experiencing gear grinding, jumping, vibration, etc...

failure_analysis.pdf

[mwt18]

Chemical Composition of TR6060 Defective main shaft (obtained from SPECTROMAX Spectrometer):



Vicker's hardness profile through cross-section of defective main shaft (obtained using LECO LR300TD):



Sample indent:

[mwt18]

Fracture location:





Macroscopic Fracture Surface Images:

Transmission side:



Drive-shaft side:

[Smoky10]

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[mwt18]

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[IROCanSS]

Ummm... I am sorry but it sounds like you got a FREE transmission???

Ask your self this... If GM is replacing ones that break FOR FREE... whats the big deal? So you are out your car for a few days. I am sure they give you a loaner.

I just dont see it. You expect GM to spend $17,500,000 for 5000 transmission that COULD BE FINE??? I see nothing wrong what GM is doing. Fix the ones that break and move along.

My friends just broke the other day. As long as GM foots the bill for the repair, I am sure hes not going to be that upset about it. Shit happens ESPECAILLY when you mod and run the car at the track.

And don't start on the "it should be built for that". Tell that to all the Corvette owners whos rear differentials blew into a million pieces. Racing causes stress, stress causes failure. PAY TO PLAY.

[mwt18]

Originally Posted by jrhaus76

Ummm... I am sorry but it sounds like you got a FREE transmission???

Ummm... NO! I paid $3000 for the new transmission. GM denied my warranty.

Originally Posted by jrhaus76

So you are out your car for a few days. I am sure they give you a loaner.

WRONG AGAIN. I was without my car for 3 weeks until I took it upon myself to get the thing back from GM and have it fixed by an independent shop.

Originally Posted by jrhaus76

I just dont see it. You expect GM to spend $17,500,000 for 5000 transmission that COULD BE FINE??? I see nothing wrong what GM is doing. Fix the ones that break and move along.

You obviously don't see a lot of things.. Maybe you should just move along.

Originally Posted by jrhaus76

My friends just broke the other day. As long as GM foots the bill for the repair, I am sure hes not going to be that upset about it. Shit happens ESPECAILLY when you mod and run the car at the track.
And don't start on the "it should be built for that". Tell that to all the Corvette owners whos rear differentials blew into a million pieces. Racing causes stress, stress causes failure. PAY TO PLAY.

You're an idiot

[SC2150]

Someone taking the time to analyize the reason for a far to common failure may help in future improvments to the product. Thats how we found the weak links in the early C5 corvette Getrags. the long output shaft has the diameter smaller between the splines and the bearing journal so they were naturally weak at the transition. The solution was a hardened replacement with the maximum diameter throughout.

But bear in mind, alot of the ones I've seen were due to wheel hop, which can break most any driveline component.

[Huggerorange73]

Originally Posted by jrhaus76

Ummm... I am sorry but it sounds like you got a FREE transmission???

Ask your self this... If GM is replacing ones that break FOR FREE... whats the big deal? So you are out your car for a few days. I am sure they give you a loaner.

I just dont see it. You expect GM to spend $17,500,000 for 5000 transmission that COULD BE FINE??? I see nothing wrong what GM is doing. Fix the ones that break and move along.

My friends just broke the other day. As long as GM foots the bill for the repair, I am sure hes not going to be that upset about it. Shit happens ESPECAILLY when you mod and run the car at the track.

And don't start on the "it should be built for that". Tell that to all the Corvette owners whos rear differentials blew into a million pieces. Racing causes stress, stress causes failure. PAY TO PLAY.

I'm going to guess that's me

I agree with the pay to play concept....except in this case. GM knows the first 25K M6 trannies are potential time bombs.

If my vin was 26K plus, my car wouldn't be at the dealer right now, I'd have the tranny out and be on the phone with RPM Transmissions.

However, given the fact that I'm 12K vin and numerous sub 25K vin output shafts are snapping...I gotta lay this one at GM's feet.

Anyone with a VIN outside the known TSB window bitching is another story. And yes, Jason's right....if GM picks up the bill for this one, you won't hear me bitching about a defective output shaft!

And he's a good guy not an idiot! I gotta stick up for him!!!

[IROCanSS]

Originally Posted by mwt18

Ummm... NO! I paid $3000 for the new transmission. GM denied my warranty.


WRONG AGAIN. I was without my car for 3 weeks until I took it upon myself to get the thing back from GM and have it fixed by an independent shop.


You obviously don't see a lot of things.. Maybe you should just move along.



You're an idiot

Sorry man, chill out. I didn't realize people were getting denied warranty for this. Jesus.

I am sticking by my comment that GM has no obligation to go out and replace everyones transmission if it falls into a certian VIN range, thats just stupid. Most of the shafts are probably fine. a select few have broke (I read the other thread). Why not just fix them when it breaks?

It sucks that GM shafted you (no pun intended) on the warranty. If you had any kind of attitude like you are displaying here, its no wonder they told you to go piss up a rope.

Hugger... thanks buddy! Best of luck on your claim and getting it back on the road SOON!!!

[ponbigi]

Originally Posted by jrhaus76

Sorry man, chill out. I didn't realize people were getting denied warranty for this. Jesus.

I am sticking by my comment that GM has no obligation to go out and replace everyones transmission if it falls into a certian VIN range, thats just stupid. Most of the shafts are probably fine. a select few have broke (I read the other thread). Why not just fix them when it breaks?

It sucks that GM shafted you (no pun intended) on the warranty. If you had any kind of attitude like you are displaying here, its no wonder they told you to go piss up a rope.

Hugger... thanks buddy! Best of luck on your claim and getting it back on the road SOON!!!

Right... because Gm shouldn't stand by their products and find every little way to get out of their warranty obligations. Tool

[mwt18]

bump for new pics. Any metallurgists in the house??

[Merc]

I broke my outputshaft (4920). Looked about the same as the one you have posted pic's of. GM repaired mine only. Now the input bearing is noisy. They will be fixxing it again. I have put them on notice that there is still issues. Bearing became noisy within a 1000km of there fix.

[Ltdodge]

maybe there is a lawyer here that would like to submitt a class action lawsuit against gm on behalf of the owners for the LS3 manual cars under 25K vin number to have the tranny replaced.