M6 Transmission Options
Thread Starter
Racer
Joined: Mar 2018
Posts: 456
Likes: 144
From: Frederick Colorado
M6 Transmission Options
My M6 loves to pop out of reverse and reverse has two or three teeth that are shattered and grind if they are engaged.
It’s time to rebuild or replace.
I will not do the replacement myself - I don’t want to get this deep into the power train as I am getting too old to work quickly enough to perform this repair, and my garage isn’t large enough to leave the car for days or weeks as components are shipped out for work.
What are my options? I live in Northern Colorado. I guess I could turn up to a local Corvette club and get the advice of members there.
What kind of budget should I set aside?
It’s time to rebuild or replace.
I will not do the replacement myself - I don’t want to get this deep into the power train as I am getting too old to work quickly enough to perform this repair, and my garage isn’t large enough to leave the car for days or weeks as components are shipped out for work.
What are my options? I live in Northern Colorado. I guess I could turn up to a local Corvette club and get the advice of members there.
What kind of budget should I set aside?
Instructor
Joined: Jan 2019
Posts: 215
Likes: 223
From: Atlanta, GA
The reverse fix really isn't that hard in itself - I did mine while I was replacing the clutch and rebuilding the torque tube. If you are not physically able to drop the crossmember and transmission and diff - I can completely understand - getting close to that point myself. But, I did find that this job was not as hard as it is sometimes made out to be. I used this
video as a reference, though with the bronze shift fork pads, I didnt use as thick of a shim as he did. I didn't have to replace the gear or synchro - even with mine popping out as often as it was. A new set of bronze shift fork pads, and shaving an shimming the shift fork did the trick for me. You only have to take off ther rear section of the transmission case where 5/6/R gears are to get to it. I did flip the synchro and used the other side of it (only one side is used for reverse). Mine has not popped out of reverse once since I did this.
Safety Car
Joined: Mar 2017
Posts: 3,770
Likes: 940
From: Orlando Florida
There is a terrific series of YouTube videos on a Corvette T56 rebuild that I recommend highly for reinforcing your thoughts on not tearing it down yourself. To my mind, it is not for average Joe. Particularly if you already suspect your garage is to small for the removal.
I’ve googled my town for good transmission shops, but just like cars they seem to run about 99 percent for slush boxes. More than one known good resources, such as RPM, but two way shipping is exorbitant.
Figure 10 to 11 hours professional labor for tranny and clutch replacement, between $110 to $150 an hour here in central Florida. A used box runs between $800 and $1500, with little guarantee it’s good.
https://www.fischermotorsports.com/f...e-t56-6-speed/
I’ve googled my town for good transmission shops, but just like cars they seem to run about 99 percent for slush boxes. More than one known good resources, such as RPM, but two way shipping is exorbitant.
Figure 10 to 11 hours professional labor for tranny and clutch replacement, between $110 to $150 an hour here in central Florida. A used box runs between $800 and $1500, with little guarantee it’s good.
https://www.fischermotorsports.com/f...e-t56-6-speed/
Last edited by redzg; Sep 24, 2023 at 03:43 PM.
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,650
Likes: 7,292
From: CT
I could not begin to guess at labor. I wager dropping the cradle, swapping boxes, getting everything raised back up is a solid day of work. Maybe two days on a weekend. I *may be tackling this for my daily in two weeks when I return from NC as my 4th gear synchro has been dead most of this year and I picked up an MM12 (Z06) close ratio box with 70k on it to swap into the car (125k). What I can tell you is that a busted box can be sold to a rebuilder for about 700 or slightly more. Finding a fresh used one..... 900 to 1500 was what had been popping up for me. Rebuilds tend to double that high number due to labor mostly and parts.
Good luck!
Good luck!
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
I'm an hour and change south of you and equipped for this repair. PM me if you want to work something out. Fair warning: your 5/6 driven gear and main shaft are likely to be worn out and in need of replacement.
