Heavy duty rearend
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Heavy duty rearend
I have seen early c3's advertised with heavy duty diff option? I cn not find info on this? was there a option , if so what was different to the regular option
Thanks
Thanks
Team Owner
Joined: Sep 2006
Posts: 31,266
Likes: 4,361
From: Westminster Maryland
H r88,
I believe that HD refers only to the type of universal joint caps used on the outputs of the differential. In 68-69, BBs used block type caps and through bolts, while in 70-72, BBs, Lt-!s and M40 cars had the block type caps and bolts rather than the U shaped clamp used on 'normal' SB cars.
Regards,
Alan
I believe that HD refers only to the type of universal joint caps used on the outputs of the differential. In 68-69, BBs used block type caps and through bolts, while in 70-72, BBs, Lt-!s and M40 cars had the block type caps and bolts rather than the U shaped clamp used on 'normal' SB cars.
Regards,
Alan
Burning Brakes
Joined: Sep 2008
Posts: 805
Likes: 5
From: Naperville Illinois
I think Alan71 is correct, but this may also be a reference to a rear-end cover that was replaced with a heavy duty cover. The rear spring mounting bolts screw into an extension cast into the rear differential cover; on a certain percentage of cars, the ends of the extension or "ears"--where the outer spring bolts attach--will break off. Both of the "ears" broke on my '68. A beefed-up (heavy duty) rear cover is available.
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
I think Alan71 is correct, but this may also be a reference to a rear-end cover that was replaced with a heavy duty cover. The rear spring mounting bolts screw into an extension cast into the rear differential cover; on a certain percentage of cars, the ends of the extension or "ears"--where the outer spring bolts attach--will break off. Both of the "ears" broke on my '68. A beefed-up (heavy duty) rear cover is available.
Safety Car
Joined: Sep 2007
Posts: 4,458
Likes: 331
From: Indy Indiana
the term heavy duty from the factiory option does indeed mean the caps instead of ubolts
the heavy duty cover is an aftermarket item and not factory.
also, the term heavy duty may mean it was posi, not all corvettes up to a certain year were posi.. At one point, and someone may chime up here as to when, all rear ends were posi.
the heavy duty cover is an aftermarket item and not factory.
also, the term heavy duty may mean it was posi, not all corvettes up to a certain year were posi.. At one point, and someone may chime up here as to when, all rear ends were posi.
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Thanks
Melting Slicks
Joined: Nov 2004
Posts: 2,672
Likes: 6
From: Nevada City California
Most '69 year Corvettes came with the optional positraction, in fact the percentage is so high, it was made standard for the model year 1970 and beyond. It was part of making the tinted glass and four-speed manual trans all part of standard equipment along with positraction.
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