I am starting a thread today on the problem I am having with my 2006 Base model / Z51 / six speed manual Vette. I previously discussed it in the thread on my Borla Exhaust buy, but it was too mixed up in that thread. So,.....as stated before, I am having a clunking noise somewhere in the driveline or transmission or shifter, most noticeably at slow speed when loading and unloading the driveline, ie.pushing clutch in and out, and even when moving with clutch engaged. It really sounds like play in splines or couplings, when load is reversed its a clunking sound. I have had comments and read posts that this is "normal" and the same amount saying it is NOT normal. So...... I reported a few weeks ago that I was taking it to a local Chevy dealer that once was a performance Chevy dealer near me.....but work schedule prevented that earlier visit. Tomorrow its going in. I am very pessimistic about this dealer really being serious about finding the problem....but I have to try. Its getting worse,....and I don't want anything serous happenning. I do have an aftermarket warranty that is supposed to cover it.......but again....very pessimistic. I am preparing for a fight trying to get this fixed. I hope I am wrong.

I will keep you posted.

 

Well....took the car to the Chevy dealer, mechanic went for a ride with me,.....and he said the noise is NOT normal. So, they are going to look into it. Unfortunately, it may take awhile, given they only have TWO mechanics at this authorized Chevrolet dealership. Warned me up front it could possibly take 3-5 WEEKS......IF parts become a problem. Said that OLD Corvettes like my 2006 may have parts supply issues. I don't have much choice....I don't know anyone else in the Pittsburgh area to take it to....and driving it to Gettysburg or Fredericksburg MD,......as some suggested is a complicated and difficult solution. Good news for me is that I didn't hear the guy say......THATS NORMAL. He acknowledged something is wrong. I take that as Step One......success.

 

maybe the torque tube needs rebuild.

 

Car has just over 17,000 miles on it. Lived its whole life in Texas till I bought it last August. Maybe it is the torque tube......maybe throwout bearing......transmission? I have no idea. It needs fixed.

 

Three days gone by....not a word yet.

 

If its bushing, couldd be because they dry rotted.

 

Try Danner Automotive in Bethel Park !!

 

Regardless of which one of the issues it is, the torque tube will need to be dropped in order to inspect. Fairly labor intensive job $$ either way. Sucks for such a low mileage car.

 

I got a PM from Rick at RKT Performance in Federick Maryland, so I called him just now. Had a good discussion with him about the problem, and he is thinking it may be ring / pinion excess lash in the differential. Makes sense to me. SO I called the Chevy dealer where the car is currently sitting.....and they still had not started into the car, and they are okay with me taking the car away, not charging me anything. So.....Rick suggested I get the car up on jacks, and move the rear wheels and see if I can duplicate the sound / play. Thats now the plan......unfortunately it means a 3.5 hour drive from where I live to RKT,.....drive back...and then return once fixed. Lots of driving, time and money, but, I feel good about what Rick told me, and taking to a place familar with Corvettes. Thanks to the forum for bringing us together.

 

Got my car back from Chevrolet.....they didn't charge me anything. I set up with Rick at RKT to take the car to him in a few weeks.

 

I sure am counting on RKT to get my driveline noises fixed.....because frankly.....driving it with these noises, it makes me see the car as junk. I hope he can do whatever it takes, plus the Borla exhaust should make it sound like a Corvette.....and then if I get a tune to get this torque management released, and a good pedal ratio set up.....I am just hoping I can get this car to be as fun to drive as my C3.

 

Although the issue is perhaps comparing apples to oranges (Camaro and Corvette) - the gen 4 Camaro Z28 was notorious for driveline clunk -even with the auto - they clunked new right off of the hauler . A typical service tech response was - they all do that - it's normal. In thousands (there's a TSB) of cases there were internal weld cracks in the aluminum driveshaft and/or too much pinion gap due to the crush sleeve. The fix was to replace the crush sleeve with a solid pinion spacer (the crush sleeve is one time use only but lazy techs reuse them sometimes making the issue worse).

To fix my 98 they replaced the driveshaft (broken weld) and reused the crush sleeve which destroyed the pinion bearings in less than 200 miles. They repaired under warranty. Believe it or not the service manager said new crush sleeves are not needed. I eventually replaced the crush sleeve myself with a solid pinion spacer. Problem solved.

Like a I said - comparing a Camaro and a Corvette.

If the diff has one and it is not solid make sure they install a new crush sleeve when they put it back together.

A good tech can determine pinion bearing issues by driving the car slowly in figure 8's.

 

Thanks for the input. I am going to put my faith in Rick at RKT and hope he finds the problem,. He seems to believe, from my description, that its a problem in the differential....and that makes sense to me. He says the tolerances on the factory builds sometimes create this problem. But I also feel something in the shifter.....so maybe its more than one issue. I hope to have it to him in a couple weeks, and get this behind me.

 

Well.....got the car to Rick at RKT Performance. His initial theory, before he drove the car, was it was excess differential gear play, which he said is not uncommon. But.....now that he has driven it, he said the sound is completely different than what the differential freeplay would sound like. He said it sounds more like in torque tube area / splines on shafts. So.....the troubleshooting continues. He has some other jobs to finish up, so it may a few days before he starts. He said its absolutely "not normal".

 

UPDATE......... Rick at RKT Performance in Frederick, MD has had the car, and been working this problem. As he suspected, the differential did have some excess freeplay, and he fixed that, put it back together, and the noise was somewhat reduced....but still there. While out, we decided to have him do his transmission upgrade package to the T56, so he did that as well. He checked everything in the driveline front to back, and finally found that the female splines in the rear end of the torque tube had excess freeplay. He showed me by inserting a good spline into the torque tube, and you could feel the excess freeplay .....so in the car, with loading / reverse loading,....it was clunking. It was the sound I described all along. He put a replacement torque tube in the car.....noise is gone. He believes that both the freeplay in the differential, and the freeplay in the torque tube...were adding up to play in the driveline that manifested itself into the noise. This car has just over 17,000 miles on it.....so I am NOT impressed with Chevrolet on this one. How can they put stuff out like this? It was just excess tolerances in the machined parts.......not wear.

I picked the car up today.....and the noise is gone. I also had Rick install an axle back Borla S Type II system.......and it sounds amazing. Perfect! The car shifts perfectly, quiet and solid.

I cannot say enough about how pleased I am with RKT Performance. Rick is a great guy, kept me informed at every step of the process, explained everything, and the best part, he was determined to fix the problem, whatever it took. His shop is full of Corvettes, driveline components, transmission, etc. and he clearly knows what he is talking about with Corvettes. I highly recommend him for anything related to Corvette driveline issues.

Next project......a tune to unleash the power built in.

 

Glad to hear things worked out well with Rick, knew you'd be satisfied. Happy driving!

 

Just got back from the first real drive on my favorite roads with this RKT Performance worked on car........all the wrong transmission noises are gone. I had Rick upgrade the T56 with all his improved internals, and maybe my imagination,......or placebo effect,.....but it shifts tight and solid all around. And the absolute best part, is these Borla S Type II make this thing sound awesome......I don't care if it added one HP, it makes it sound like a Corvette should, and changes the car dramatically into something alot more fun to drive. I don't really need anything else to be satisfied with the car 100%......but as I said, when I have time, I may get a Diablo tune just to unleash the existing power that Chevy choked on this thing. Otherwise, it accelerates just fine for me and the driving I do.

 

Great to hear it, hopefully lots of miles and smiles ahead brotha! Enjoy!