I've never broken a rear end like this before...............
I dropped my driveshaft on the starting line at Mason Dixon Dragway durning the Slant race back in July (was it?). At the time I just thought I had sheared the bolts where the driveshaft meets the companion flange.

This weekend I got up under it to work on it and found the pinion snubber on the diff housing was touching the floor of the car! Whaaaa?...........

At first I thought the mounting perch at the spring must have broke off on each side and rotated. Nope that wasn't it. What happened was the axle tubes rotated where they are pressed into the diff housing. Hmmmm, never seen that happen before.

Anyone else seen this? How the heck do I go about fixing this one?!

Oh it is a 8.25 SG rear if that makes a difference.

Thanks,

CE

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Wilad ass guess- cut thew spring perches off the tubes, re-weld them where they need to be, reinforce the tubes at the pumpkin by welding them in place?

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Casually looking for a Clifford hyperpak intake for cheap.

Chris,

Before you rip it out of the car and cut off the perches, I think I would try to rotate it back down if it will move. I would try putting a small scissor jack between your snubber mount and the floor and see if it moves easily. Likely it wont. Apply some heat to the outside of the case where the tubes press in and see if that will help it to move. If it does, rotate it until you get the proper pinion angle. Then I think you have to check it somehow and see if everything is still square. Maybe pull the axles and backing plates, put a sqaure on the face where the backing plates bolt on.Have the square stick up above the housing far enough to run a tape measure straight across to the other side. Have a helper do the same on the other side, and measure the distance between the sqaures. Now flip the squares over and put them the same distance below the housing as you did above for the first measurement. Measure between the squares. The measurement should be the same. If you get those measurements the same (top and Bottom) And the distance from the housing out to the end of the tube is the same side to side, I'd weld it up and give her another try.

Hope that all made a little sense?

Rick.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

I had a "leg" come loose on a 7 1/4 and cause a pretty messy leak, we recentered and welded it down, then used some epoxy to seal it... it worked.
With yours...I would try to "counter-rotate" the center-section of the unit, back into the correct position, while it is still bolted in the vehicle. If you can get it to move back into position, scribe some lines & remove for re-welding. It would be best to use a rear end narrowing jig to hold everything centered prior to welding.
DD

DANG, that car makes some pow-AHHH. Crazy failure! Yeah, what Doc and Rick said.

You could also think about a different rear? Ford 8", Ford 7.5 or 8.8", Mopar 8.75"... Probably best to stick with yours, if you can fix it. You could sell the SG guts to Sam Powell??

Only ~10 months until M-D race 2011!

Lou

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Home of Slant6-powered fun machines since 1988

Yep, that slant is a TORQUE MONSTA!!!!

Well I already pulled the rear so I guess I can try to figure out some other way to rotate it back. Ugh.

I can weld it up too once I get it in place. I was thinking about drilling through the holes on either side of the diff cover and tapping them for plugs. Guess welding them shut would do the same thing really.

Thanks for all the ideas guys. I'll let you know how it turns out.

CE

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Lou, remember how on my last time trial I picked up a full second on my time and had a funky noise in the car? And then we pulled off the valve cover looking for noise?

It was the next run, the first run of the actual race that I dropped the shaft on the track.

I wonder if I hadn't rotated the rear slightly on the last time trial launch and then broke it on my first run. That would probably answer the noise question, and may even answer the picking up a second on my time.

Thoughts?

C

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Yep, sounds like it might have partially slipped and gave you a better hookup, thus the faster time, then broke fully on the next pass. Wow, a full second? I didn't remember that. What was the faster time?

Lou

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Home of Slant6-powered fun machines since 1988

I have heard of slipper clutches, but never a slipper rear? Maybe it will catch on.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

SORRY! "LOST" a full second. I was running 16.2 -16.4 and went to a 17.2 on the last time trial.

Gotta learn the drag racing lingo

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

OK, that makes more sense. Yep, lingo sounds backwards, doesn't it.

Lou

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Home of Slant6-powered fun machines since 1988

Its not that simple. The backing plate flanges are also welded to the tubes. They would also need to be reoriented to maintain the brake system geometry (bleeder highest, hardline and hose routing). It would be easier to rotate the tubes back into position.

The tubes are a very tight press fit. You'll need to fabricate a jig to hold the differential housing in position while applying torque to the tube, probably bolted into a concrete floor. You'll need to cool the tube (dry ice/acetone slurry will be ~-78F iirc), then quickly heat the housing with a weed burner. The tube will need to be insulated from the flame. You'll need to rig up some means of stopping rotation once the correct orientation is reached.

Ken

could just put it in reverse and mash the throttle......