KevinZ51C6

So starting about a year ago I noticed a slight grind going from 2nd to 3rd gear. It would only happen once in awhile and it wouldn't be at or near redline, but normal acceleration shifting around 2K if I shifted too quick. Definitely feels like metal to metal contact. It never happens if I intentionally shift slow.

Seems like it's getting worse now and happening almost every day. Could it be the shifter out of alignment? Should I flush the tranny fluid and try an MGW shifter?

I don't beat on the car and I flush the clutch fluid every month BTW.

Thanks guys
Kevin

dgrant3830

I don't know yet if the C-6 has the same alignment pin on the shifter that the C-5 has but if it does, that's the first thing to try...shifter alignment.

Rick@RKT Performance

It sounds like synchro issue but as ndgrant3830 has stated, try the shifter alignment first. Then try fluid change and last resort would be to go into the trans. Good luck.

LTC Z06

Rick, sometimes my 2005 will not go into first, like there is shift lock on it, I have to double-clutch to get into first. What is the problem?

Rick@RKT Performance

How many miles do you have on the trans? Most common problem with going into 1st is the plastic fork pads that have deformed. Worn blocking rings could cause that also.

LTC Z06

29,000 miles of normal driving.

LTC Z06

Thanks for the help Rick.

Rick@RKT Performance

No problem, anytime.

RicK T

Not to step on what Rick@RKT56 offered but just adding that if you're talking about a reluctance of the trans to go into 1st from neutral while stopped then it is likely due to the design of the gear teeth, a known issue that was solved with the TR6060 in '08. Here's some explanation if you're interested.

http://forums.corvetteforum.com/1562288138-post3.html

WHYASK

have the same problem as the going into first issue also have trouble of it locking me out of downshifting like something is blocking it .. 65k on the odometer.. Tranny was just flushed & refilled with all new fluids 4 days ago and still the issue...?? ANythoughts..

C7&7

It's really sounds like the synchro. Friend of mine's 04 Z06 was doing the same thing with only 15K miles on it.

I would look at the shifter alignment though just to be sure. Also flushing all your fluids is worth a shot. Good luck.

WHYASK

What is this shifter alignment I keep hearing about ???

dgrant3830

I know its on the C-5 for sure but I don't know that its on the C-6 but would hope so. therefore, on the C-5, gain access to the shifter. On the front of it there's a pin that is located in a storage position up, but facing down. What you would do is to put the shifter in neutral, then push this pin down into the mechanism which will lock it up completely. Then loosen the torx bolt holding the shifter to the shift rod going to the transmission. It will automatically center itself where it should be. Then tighten up the bolt again and restract the pin back into the storage position and put her together.

KevinZ51C6

I'm gonna try an MGW and a tranny flush. What is the reccomended tranny fluid for our cars? I remember some talk of DEX 4 or something similar that was supposed to be superior to the original OEM fluid.

Rick@RKT Performance

I use GM fluid #88861800 for T56 and TR6060's.

Joe_G

I had this problem with my 05 trans too. I got in the habit of going from 2nd to first and even then it balked sometimes. The problem was fixed when my trans was rebuilt after breaking my rear end.

I hope you find a better fix.

I recall I had a similar balky first gear in my C5, and it was nearly remedied by using, if I recall, GM Slick Shift transmission fluid.

Rick does my memory serve? Did/does GM sell "slick shift" fluid? Do you think it would help?

Appreciate you chiming in on these trans/diff threads.

Toque

I had the same issue on my 04Z as tim stated above. It was a 3-4 grinding issue on my tranny. Only happened at low cruising rpm's. Never happened at high rpm shifts that I can remember. My tuner told me the syncros are mostly used for low rpm to sync the tranny. Exactly what I described to him about my issue. Started happening to me around 18k miles. I tried shifter alignment and fluid change. Did not help at all.

My tuner rebuilt my tranny with all rpm hardware and now its perfect! No more grinding.

Try the shifter alignment, and fluid change first. I fear it might not help though....

Good luck!
Toque

WHYASK

Tranny flush and shifter alignment later still crap.... hope the OP has better results '( WOuld just getting a TR6060 be a better investment than upgrading the internals of a T56 ..??

Rick@RKT Performance

LOL, I think the Slick Shift was an aftermarket company and not a GM fluid but I know what you're talking about. I don't think they make it anymore.

Even though I run a business, I'm alway here to help anyone out if they have questions. I'm first a car/Vette guy. I have helped members rebuild their own trans/diff so it's not about just business.