How much will a '80 Diff Handle?
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
Hi Mark, thanks for the pic.
First step is to use a new C4 D44 carrier. You can see in the pic, just to the right of Mark's thumb, the step in the carrier which solved the problem with the discs stripping the retainers.
The big item is the steel cap. I make them massive. The right side cap at the bottom of the pic shows the notch for bolt head clearance where they always crack at.
All the magic is in the machining. Machining the cap pads true to the carrier centerline. My cap uses a large portion of the case for support also. The side of the housing is not a flat wall perpendicular to the carrier. It has a slight angle going towards the centerline. And no two cases are alike. I have to hand fit every cap. You can also see that where the cap meets the housing I machine the step flush to the gasket surface. The batwing actually sits on top of the step for additional support.
What you can't see is the step inside the cap and housing that the bearing race bottoms on. Once the cap is fully machined and fitted I have to bore the step to hold the race square. All together it's about 30 hours of machining and fitting.
First step is to use a new C4 D44 carrier. You can see in the pic, just to the right of Mark's thumb, the step in the carrier which solved the problem with the discs stripping the retainers.
The big item is the steel cap. I make them massive. The right side cap at the bottom of the pic shows the notch for bolt head clearance where they always crack at.
All the magic is in the machining. Machining the cap pads true to the carrier centerline. My cap uses a large portion of the case for support also. The side of the housing is not a flat wall perpendicular to the carrier. It has a slight angle going towards the centerline. And no two cases are alike. I have to hand fit every cap. You can also see that where the cap meets the housing I machine the step flush to the gasket surface. The batwing actually sits on top of the step for additional support.
What you can't see is the step inside the cap and housing that the bearing race bottoms on. Once the cap is fully machined and fitted I have to bore the step to hold the race square. All together it's about 30 hours of machining and fitting.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
...And thanks also to TheSkunkWorks for the info on costs involved with a 12 bolt setup. I just finished a 509BBC major redo on my Nova, which went over budget. Costs on this project will be of consideration, as I'm doing the whole car i.e. new interior, paint, and installation of a '82 CE openable rear hatch.
Thread Starter
Racer
Joined: Aug 2005
Posts: 289
Likes: 64
From: Tacoma Washington
Since my 1980 rear is still in the car, I popped over to eBay and saw a 1980 diff for sale which included pix. Noticed the diferences in the carrier and your mega cap. Very nice work! If all the mods you do are done, wha kind of strength increase can be expected?
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
The weak points go from carrier issues ( fixed above) to gear issues , it is a SMALL ring and pinion and will not survive high torque / horsepower launches on sticky tires .. IMOP ..
I have dual billet caps , machined , ect ect ect , auburn pro posi .. And I killed the gear set.
There is a reason GM made 12 bolts . .. And why people use ford 9 inch rears .. And a dana 44 can not hold a candle to them because it was never meant to .
I have dual billet caps , machined , ect ect ect , auburn pro posi .. And I killed the gear set.
There is a reason GM made 12 bolts . .. And why people use ford 9 inch rears .. And a dana 44 can not hold a candle to them because it was never meant to .
