M6 Shifting Forks
Thread Starter
On The Tree
Joined: May 2002
Posts: 108
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From: Richmond, Virginia
M6 Shifting Forks I met a guy with a 99 Z with the M6 Transmission. My car is a 98 with the M6. He said GM had problems with the shifting forks in the M6s and the worn forks took out his synchros. On my trans, I noticed that it does not have the smoothest feel when shifting gears other than gently. Sort of feels like the 5 speed that was in my 85 Z. My problem may be clutch related ( car has 46k on it), shifter related (I have a new short throw I am going to install), or shift fork / synchro related.
Also... I have read that with the M6 trans, the rear axle gear is 3.42, yet when I have checked my car at various speeds, gears etc... everything points to it having 3.73. I will jack it up and actually check what his has by tuning the drive shaft and counting while the tire makes one revolution. Does anyone know if the LS1's were available with 3.73 from the factory. I tend to doubt that this had an aftermarket install. The tires are 245-50-16.
Does anyone have any thoughts on either of these two items.....
Thanks....
Also... I have read that with the M6 trans, the rear axle gear is 3.42, yet when I have checked my car at various speeds, gears etc... everything points to it having 3.73. I will jack it up and actually check what his has by tuning the drive shaft and counting while the tire makes one revolution. Does anyone know if the LS1's were available with 3.73 from the factory. I tend to doubt that this had an aftermarket install. The tires are 245-50-16.
Does anyone have any thoughts on either of these two items.....
Thanks....
I can shift faster than you.
iTrader: (21)
Joined: Nov 2001
Posts: 5,133
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From: Baton Rouge, LA
Re: M6 Shifting Forks All 6-speed LS1 f-bodies came w/ 3.42 gears from the factory.
There was a Technical Service Bulletin for the 3-4 shiftfork on the T56s. GM went to an upgraded piece. Does your tranny pop out of gear at all or is the shifting just notchy?
I'd recommend either changing your tranny fluid or replacing the entire clutch hydraulic system with '01+ parts.
There was a Technical Service Bulletin for the 3-4 shiftfork on the T56s. GM went to an upgraded piece. Does your tranny pop out of gear at all or is the shifting just notchy?
I'd recommend either changing your tranny fluid or replacing the entire clutch hydraulic system with '01+ parts.
Thread Starter
On The Tree
Joined: May 2002
Posts: 108
Likes: 0
From: Richmond, Virginia
Re: M6 Shifting Forks Thanks for the information. The trans jumps out of gear very very rarely, and just when making a start from a standstill after backing out of a parking space. It mainly just feels notchy.
I will be replacing the Hydraulics with the 01 type as you have recommended and use the Mcleod Adjustable Master Cylinder. I am also going to do the drill mod on it, and eventually replace the stock clutch. I am also going to change the fluid, I just got some B&M Stick Shift Fluid and will give that a whirl. I am going to have to verify my rear axle gears based on what you wrote and what I have read elsewhere, that with the M6 the rear was 3.42. If the rear is indeed a 3.73, then the last owner must have changed it out, saving me the trouble of having to do it.
Thanks for your reply..... Good Luck with your Car......
I will be replacing the Hydraulics with the 01 type as you have recommended and use the Mcleod Adjustable Master Cylinder. I am also going to do the drill mod on it, and eventually replace the stock clutch. I am also going to change the fluid, I just got some B&M Stick Shift Fluid and will give that a whirl. I am going to have to verify my rear axle gears based on what you wrote and what I have read elsewhere, that with the M6 the rear was 3.42. If the rear is indeed a 3.73, then the last owner must have changed it out, saving me the trouble of having to do it.
Thanks for your reply..... Good Luck with your Car......
