Rearend Alignment

[RudeDog]

Howdy All -

I bought a '78 that had custom tires on it that were wider than the stock tires. I noticed that the inside of the drivers side rear tire would rub against the body (made a loud squeaking sound) occasionaly. I checked the distance from the inside edge of the tire to the body and I couldn't even fit my finger between the two on the driver's side but more room on the passenger side. I put the stock tires back on so that I would have clearance until I could get some time to figure it out. Then I began looking into getting the backend aligned properly so that I can even out the clearance on either side of the rearend and get the custom tires back on. Problem is that I don't see that there is any adjustment to moving the backend side to side in relation to the frame. The adjustment that I think I would need to accomplish this would be to lengthen the panhard rod just a bit but it seems to be a fixed length. Is there something I'm missing?

Rudy

[manoa matt]

The rear differential design was changed in mid 78 so you may have an early or late diff. The early differentials were one solid piece with the center section bolted on from the front and no inspection cover. The later ones use a cast center section with tubes pressed in. It has the inspection cover. The early differential will have a straight panhard bar, with a compressed/flattened section directly in front of the diff center. The late diff will have a panhard bar with a jog in in and a compressed/flattened section directly in front of the diff cover.

Its possible the panhard bars were mixed up if someone ordered one without the proper verification.

Also check all the structural and sheet metal around the whole rear half of the car for signs of an accident/damaged/repaired areas. Look for welds that look different or sloppy. Check the condition/existence of all the rubber bushings at the upper and lower trailing arms, also note if the lower trailing arms are bent. The rear trailing arms are not jacking points.

[maytag]

Is anyone certain that the early and late panhards are different lengths? I've been told that they are the same length. So we should verify that before we go goose-chasing.

Rude-dog; as you've already deduced from a close inspection of the geometry of the rear, the left/right "alignment" of the diff-housing assembly will also be dependent on the ride-height. if you have significantly lowered the car (or removed the bumpers and left the springs alone) then the distance between the two anchor points will want to change as well... but the panhard won't allow it, of course. This will result in a minor shift of the rear diff centerline, relative to the body centerline.

[halg]

Here is a photo of the 3 panhard bars I know of
Hal

[spiderrey]

Huge difference

[maytag]

Huge difference

CHA!!!

Thanks for that, Halg!

This makes me think that there's no way you're gonna get the one on the other though.

[MNspiderman]

Maybe when this guy changed out the rear end he was thinking about his chevy nova days and was compelled to make this fiat dog track as well. OMG some of those novas dog legged so bad they looked like they were driving sideways. FYI, usually if the centerpin on a leafspring stack breaks/rots away that is a major contributor to dog legging. Thats is for a leaf spring rear end, of course. Does anyone remember seeing a Nova dog leg?