Posted 1/31/2010 00:09 (#1050085 - in reply to #1049567) Subject: Re: 2 speed rearend quit working on 77 Chevy C60
S.E. IL
1. It's probably a 67' not 77'
2. "JDDRIVER" photo #3 is not a VACUUM BRAKE BOOSTER, it is a two speed rear axle vacuum shifter
3. Likely it does have a hole in the diaphram. Take the diaphram to NAPA I'll bet they can order you one.
4. I have seen them do as Von suggested with the outer housing moving instead of the inner.
5. Good luck!!