C beam install question
Thread Starter
Pro
Joined: May 2025
Posts: 613
Likes: 146
From: OK
C beam install question
Got it back in fine but there is a lot of room for install position variance between all four of those bolts in the vertical plane.
Are they to be installed at full droop, full lift, or a best guess of middle ground?
I see the clearance specs in the manual but they don't make much sense, there are a dozen plus different
distances one could find to measure on the top and side unless I missed where it specified where to measure.
And I don't know how you'd adjust the side to side anyway. It's on a lift and I have screw jacks so I can put it
pretty much wherever I want, just dunno where.
Are they to be installed at full droop, full lift, or a best guess of middle ground?
I see the clearance specs in the manual but they don't make much sense, there are a dozen plus different
distances one could find to measure on the top and side unless I missed where it specified where to measure.
And I don't know how you'd adjust the side to side anyway. It's on a lift and I have screw jacks so I can put it
pretty much wherever I want, just dunno where.
Melting Slicks
Joined: Apr 2005
Posts: 3,243
Likes: 164
From: Folsom CA
Position is critical.
If you have the ZF6, buy The ZFDocs CBeam plates. They come with shims to put the transmission in exactly the right place.
https://www.zfdoc.com/c4beamplate.htm
These might work on an automatic transmission as well.
Crabs
If you have the ZF6, buy The ZFDocs CBeam plates. They come with shims to put the transmission in exactly the right place.
https://www.zfdoc.com/c4beamplate.htm
These might work on an automatic transmission as well.
Crabs
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I'm like S Carter. After holding my mouth just right (jacking the trans tail just a hair, I got all four bolts in, tightened as hard as I could and called it a day. That was 15yrs ago. Gee, Did I do something wrong? LOL
Thread Starter
Pro
Joined: May 2025
Posts: 613
Likes: 146
From: OK
The book actually says those measurements are to the driveshaft damper, which is gone on my car and a lot of others apparently, so it's nothing to do with orienting the c beam in space just clearance for that damper.
I conclude slop in the bolt holes is within 40 year old GM tolerance.
It's also of note that on examples that have been into by line techs that aren't going to sit there with two jacks piddle dicking around to line bolts up but will instead hammer on the bolts and pry around on the beam till they go on, there will likely be more play in the upper bolt holes. Price of old cars. There was considerable aluminum imbedded in the threads of all the bolts on mine and hammer marks on the beam.
Luckily this isn't a precision machine.
