Gold Lifetime Member
Join Date: Aug 2008
Location: Huntsville, AL area
Re: 'Service Duty' rear ends for '69 Z28?
Thanks for the reply and the welcome Eric, and although that article tells a *lot* of the story, I don't think it is 'complete'... As I understood from my friends, the 'service duty' third member was almost totally different from the standard JL8 RPO. The housing, bearings, axles, and brakes were different (heavier and stronger). My understanding was that the 'service duty' rear end could not implement a standard emergency brake as could the JL8 package... Maybe I was told wrong (although both guys who told me the story ordered NEW Z28's in '69 (one with JL8 and the other with standard rear, but he installed the service duty rear end) and both raced in SCCA and IMSA GT for several years with those cars. They drove them from the dealership where they picked them up, directly to their shop where they began stripping off unnecessary parts to convert the cars to IMSA GT cars. I have some of the parts removed at that time! And I have the service duty rear end that Bob Christianson had installed in his '69 Z28 (RACE enterprises car). I have two sets of axles for that rear, one with quick change studs and the other with standard studs. One reason Bob quit running those rear ends, was that the service duty axles became 'unavailable' from GM! That is most of what I recall from what I gleaned from Bob 30 yrs ago... but I have little documentation backup for any of that, although I DO have a copy of his original 'Chevrolet Race Prep' manual, mostly handwritten by GM engineers in how to setup and race Camaro's and Corvettes for road racing! This was the original precursor to the later mass produced manual which Chey sold in their parts stores! I'd love for anyone having additional information about the service duty disk brake rears to post it here.. If there's any interest, I'll drag out the one I have and make some photos....