Figment

I'm familiar with under the hood of just about anything mopar, but I'm lacking the knowledge with the diff's.

On my '76 NYer I know it's a C body, but did these only come with 8 3/4 diff. or did they come with something other than that? What else is there for choices? How can I tell the difference? What should I be looking for? If this subject has been covered elsewhere can you post the link?

The reason why I'm asking, is because I've shown up some punks when they are laughing and pointing from their ricer's (god I love that 440) but I'm always feathering the gas to keep from doing the gay one wheel peel. Sure grip is in order and I will be going to the wreckers to find one, cause is tight and I've invested every last available penny into go and whoa so far. This machine is also my daily driver so I wont be welding the spider gears. Any and all help is greatly appreciated. If I'm gonna lose a challenge from one of these yahoo's it wont be from lack of traction.

MercuryDon

Should be a 8 3/4 diff. If it is it will have a pumpkin and no rear cover.

toad490

Quick and easy way to tell if it's a sure-grip/posi is to jack boh wheels off the groun and turn one wheel by hand. If both wheels turn in the same direction it's a sure-grip, if the opposite wheel turns in the opposite direction it's a pegleg.

78D200

Take a look at this thread here. It has a breakdown of some axles. It should help you to at least identify what axle you have.

https://moparforums.com/forums/f76/a...hematics-7801/

Crazy4Carz.Com

Tough find in a junk yard. Maybe look on Ebay for a sure grip unit and have someone install it in your chunk. There is unfortunately no way to tell the wear on the unit from a yard. with a new unit you know what you have. It is possible to get a used-up center posi unit and be no farther ahead than where you are now.

440roadrunner

Here's the easy way to ID Mopar rear axles. The earlier thread posted has a lot of junk about 4x4's that may be confusing. (Dana 44's were never used under these cars)

This page:

http://www.crankshaftcoalition.com/w...tter%27s_Guide

has an easy to see chart. I don't believe up to/ including 8 1/4 would be under your car, probably the only two would be either 8 3/4 (as mentioned the ONLY axle with a third member) or the 9 1/4. I don't believe there is any possibility you would have a Dana 60.

440roadrunner

An even easier way is to block the FRONT wheels, and jack up ONE rear wheel. Make sure the parking brake is released AND the car is in neutral. You can then turn one wheel and the driveshaft if it is NOT a limited slip/ posi/ sure grip axle.

Figment

This I'm aware of, but, the owner of a local yard has a lot of older cars with their rear ends in them. The bonus is the owner bleeds mopar himself and not to picky if I rip it apart right there in the yard in the back of my truck to make sure it's a good one hell he might even let me use his air tools. Thanx guys for the links, I really appreciate it and found out it's an 9 1/4.
I did exactly this to find out before I posted the question. Thanx.

Barfly

I got a lot of good help last fall from the guys around here when I was replacing the gears in my rear end. Below are links to the threads...

https://moparforums.com/forums/f62/d...ntial-id-6865/
https://moparforums.com/forums/f62/we-under-way-6951/
https://moparforums.com/forums/f6/major-wine-6982/

Good luck, and really all you need to do is invite the ricers to the local drag strip

Joe.

toad490

Yes 440 your right, it's SOOOO MUCH easier to jack up one wheel than two!!!! Boy do I feel stupid.

toad490

Or you have a completly screwed rearend, both wheels off the ground will tell you if you have ceased bearings or not, among other things, like a broke ring or pinion gear. With both wheels off the ground you can hear any bad things in the rear, with one wheel of the ground and the wheel dosn't turn how do you know it's not a f...ked rearend? Easier is not allways better.