Late model 6-speed Trans owners.......

[NCGuy68]

I know many of you enjoy 'banging' that Tremec built M6 including myself. However, they're not indestructible. For owners of 'Modified' 93-02 F-Bodies, I offer the following from GM Tech Link, Sept, 03 edition:


Primary Condition: Unable to shift out of 4th gear.

Other conditions: 3-4 upshift- Gear clash, or block-out. 2-3 upshift-hard shift, gear clash, or block-out.

Fix: Replace the aluminum 3-4 shift fork with iron 3-4 shift fork, P/N 88996653. Also replace the 3-4 synchronizer, P/N 12523078 and the 3-4 blocking ring
P/N 12523186.

Current 'flat rate' at a GM shop is $85/HR in my area. The job pays 12 hours plus parts. Of course, if you know a good tranny man, you could come away cheaper.

[Chevy454]

If I'm not mistaken, the T-56 in the Viper and ZO6 uses the good forks from the factory, and they use different (steeper) gear sets as well. Maybe Matt Murphy will jump in here and confirm/deny this info...

[NCGuy68]

Rob....you're right, the 02-03 Z06 has the upgraded tranny shifter parts but not sure about the different gear ratios/sets. I'll check on it when time permits.

GM insiders say that the 05 ZO6 will be 425-450 HP based on a Gen. IV small block. Perhaps our friend, Matt Murphy can chime in on this one.

I know that Viper is using a version of the T-56, just not sure what Dalimer/Chrysler has spec'ed it at. I'll find out in time and report it on this site.