I've owned a '69 Z28/RS since 1976, and sometime around 1980 I bought a 'used ' Service Duty rear end from a friend who had raced a '69 Z28 in IMSA for many years. He told me this rear end was much stronger than the factory rear end as it used axles and axle housings as beefy as the full size 12 bolts of that year, but all sized for the Camaro. The axles are very FAT at the outboard ends, and use larger bearings, but taper down at the splined end. Of course this rear end came with heavy duty brakes, and did not incorporate an emergency brake mechanism since it was for 'racing only'. I've never installed this rear end in my car, but would like to get more information about it, and if installing might be a good thing to do. Can anyone shed any more light on this subject?

I'd asked this question previously, but someone replied that it was the 'same' as the JL8, but it is not. The housing, axles, brakes, etc are larger HD versions, and it doesn't allow for an emergency brake.

Can anyone add anything to this?

Never heard of a H-D Service '69 rearend?

All 12-bolts are basically the same except for the later P/U jobbers. They just vary in width.

David, you out there??

pdq67

I bought a 'used ' Service Duty rear end from a friend who had raced a '69 Z28 in IMSA for many years. He told me this rear end was much stronger than the factory rear end as it used axles and axle housings as beefy as the full size 12 bolts of that year...... this rear end came with heavy duty brakes, and did not incorporate an emergency brake mechanism since it was for 'racing only'....... Can anyone shed any more light on this subject?

I remember seeing that rear end described, what parts to use and how to build one, in the Chevrolet "green sheets" that Z28 racers got, back in the day. Sadly, the "green sheets" were about the only paper thing I didn't keep.

I believe that it had larger wheel studs as well, heat treated ring and pinion...

Contact member Johnz about it.If he doesnt know contact Jerry MacNeish.

Is it a disc brake rear, or drums?

Read the 3rd paragraph of RPO JL8:
http://www.camaros.org/suspen.shtml
and
http://www.camaro-untoldsecrets.com/articles/rpo_jl8.htm

I remember seeing that rear end described, what parts to use and how to build one, in the Chevrolet "green sheets" that Z28 racers got, back in the day. Sadly, the "green sheets" were about the only paper thing I didn't keep.

I have a copy of that 'original' green sheet 'Power Book' for racers.... Yes, it is discussed.

Is it a disc brake rear, or drums?

It is a disk brake rear end. I believe the brakes that were used were the HD Corvette units (for racing). The caliper bracket that was used may have been different than the JL8 bracket, and I believe that unit did not accept the 'drum' type emergency brake as did the JL8 and Corvette rears.. at least it didn't come with them.

Read the 3rd paragraph of RPO JL8:
http://www.camaros.org/suspen.shtml
and
http://www.camaro-untoldsecrets.com/articles/rpo_jl8.htm

OK.. I just read those two articles, and I did get a little additional information. The most informative for me was finding out that apparently the 'service duty' rear end Would accept the corvette parking brake mechanism! Now, I'm thinking I should probably install that rear end in my Z28, and incorporate the corvette emergency brake parts.. I also have Corvette front brake calipers to change out instead of the stock single piston front calipers. (Not that I really want to go to 4.11 rear end, but that's what it is..).