grinding only in first
Instructor
Joined: Oct 2012
Posts: 138
Likes: 0
From: Monroe NC
they told me that gm didn't make the transmissions anymore and that a rebuilt non gm one they found would be 4600 installed, plus 900 for a clutch if I wanted to do that as well. I don't have 4-6k to spend right now on this. was hoping I could just change the first gear synchronizer.
Melting Slicks
Joined: Jan 2007
Posts: 3,021
Likes: 133
From: Conejo Valley CA
For what the dealer wants, you'd be 1000 times better off putting in an RPM transmission. By the way, it is a sad reality but the T-56 transmissions in our beloved cars suck. I had to replace mine after a mere 50,000 miles. I had the same thing... grinding in first gear.
The thing to remember is when the tranny is taken out, there's access to a lot of stuff which is very costly to get to...If the OP can find the financial resources to do this, AND, if the plan were to keep the car for a long time, I'd recommend:
- RPM tranny
- replace transmission mounts
- replace clutch, pressure plate, throw-out bearing, clutch master cylinder
- add speed bleeder
- replace torque tube couplers and bearings
- replace rear differential axle shaft seals (drivers side is notorious for leaking)
-optional: DTE brace
The thing to remember is when the tranny is taken out, there's access to a lot of stuff which is very costly to get to...If the OP can find the financial resources to do this, AND, if the plan were to keep the car for a long time, I'd recommend:
- RPM tranny
- replace transmission mounts
- replace clutch, pressure plate, throw-out bearing, clutch master cylinder
- add speed bleeder
- replace torque tube couplers and bearings
- replace rear differential axle shaft seals (drivers side is notorious for leaking)
-optional: DTE brace
Safety Car
Joined: Feb 2014
Posts: 3,802
Likes: 322
From: Fort Worth Texas
2017 Corvette of Year Finalist
2016 C5 of the Year
My 1st gear syncro has been bad for a long time. As long as I shift into 2nd then first only at complete stop it doesn't grind and you wouldn't even know there was an issue.
Of course I want it fixed so I am going to do the rebuild with the better forks, etc and I am still looking at $1400 and better than the stock when done.
Of course I want it fixed so I am going to do the rebuild with the better forks, etc and I am still looking at $1400 and better than the stock when done.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
I personally wouldn't spend any money on a transmission until I had ruled out the other, much less costly and equally likely causes (like master cylinder, throw out bearing, etc). And as others have mentioned, if I got a tranny, I wouldn't pay $4600. Get a rebuilt unit. Many out there from very reputable sources including many forum vendors. 
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AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Instructor
Joined: Jan 2014
Posts: 167
Likes: 107
From: Edmond OK
This post by gtrslngrchris intrigues me
"Mine had a similar problem when I bought it and aligning it didn't fix the problem although it was slightly out of alignment. A combination of a B&M shifter intended for an 08+, 2x spacers for the detent, changing the fluid for the newer GM dex iii replacement and another final alignment seems to have almost completely cured my problems. Does reverse give you any grief?"
I think I read somewhere that the early M6 had paper/composite blockers with the scnycro's. I have had problems with scyncro's becoming bonded/gunked with varnishs and fail to spin freely, thus not doing their job properly. Mostly due to the wrong fluid being used or lack of maintance.... just a thought.
"Mine had a similar problem when I bought it and aligning it didn't fix the problem although it was slightly out of alignment. A combination of a B&M shifter intended for an 08+, 2x spacers for the detent, changing the fluid for the newer GM dex iii replacement and another final alignment seems to have almost completely cured my problems. Does reverse give you any grief?"
I think I read somewhere that the early M6 had paper/composite blockers with the scnycro's. I have had problems with scyncro's becoming bonded/gunked with varnishs and fail to spin freely, thus not doing their job properly. Mostly due to the wrong fluid being used or lack of maintance.... just a thought.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
You need to get the car in the air and remove the inspection plug at the bottom of the bellhousing. Have someone actuate the clutch and make sure it is fully disengaging. Not at home with the FSM, but it should tell us what the clearance should be. You measure it with simple feeler gauges.
The dealership should have done this to rule that out.
The dealership should have done this to rule that out.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Thread Starter
Instructor
Joined: Aug 2007
Posts: 168
Likes: 0
From: Cherryville North Carolina
meh, took it to another shop and they said the 1st and 2nd gear syncs were bad, plus the clutch. said you had to buy/change all the syncs together and couldn't do them separately. was charging 4100 total to rebuild it plus new clutch. don't really have that money to spend anymore on an old car so probably just going to sell or trade it in
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Thread Starter
Instructor
Joined: Aug 2007
Posts: 168
Likes: 0
From: Cherryville North Carolina
I'm having the trans in my 03 z rebuilt right now, tick stage 1 rebuild, monster stage 2 clutch/flywheel, new slave, remote bleeder, and labor for under 3k. Stay away from dealerships. My work is being done by a reputable shop. My rebuild is due to the trans popping out of reverse. If you skipped the clutch, you could have it all done for around 2k.