c3 trans shift noise
Thread Starter
Instructor
Joined: Dec 2009
Posts: 206
Likes: 2
From: Solomon Kansas
c3 trans shift noise
1969 c3 , 350, 400auto. When shifting from park to reverse, there is a loud bang as if someone is hitting the floor board with a sledge hammer. Put the car in neutral, them into drive does the same. All with the foot on the brake. When the trans was rebuild there was a shift kit added, but I understood that would only be noticable from 1-2 2-3 shifts. I will have to get it on a lift, and have someone watch to see if anything is loose. All U joints are new. Are there any rubber mounts on or near the rear trans crossmember? Thanks for any insight to this issue.
Melting Slicks
Joined: Aug 2005
Posts: 2,683
Likes: 34
From: Working on the car NY
Sometimes you can minimize the effect by first putting it into D, then quickly pass N into R. Obvioulsy do all this with your foot on the brake.
ps. you have "kicked out" the fast idle, right?
ps. you have "kicked out" the fast idle, right?
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
If the diff mounts are good and you still have the noise, check the two bolts that mount the bracket (that holds the front mount) to the diff housing. If those bolts are loose, the diff housing can move and cause a clunk.
Pete
Pete
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Drifting
Joined: Aug 2019
Posts: 1,508
Likes: 495
My bet is they left out the Wave plates in the Reverse and forward drum which cushions the initial hit of the pressure plate , I accidently installed a flat instead of a wave plate in the reverse clutch one time that always banged going into reverse before I pulled the unit and installed the Wave plate , just a hunch