Differential question

[Dreadl0ck]

I'm looking into getting the rear end fixed before cruising season. I got a 8 3/4 rear end with what seems to be a 489 house.

When I lift the car the wheels turns the same way, and with one wheel on the ground I can't move the other using hand force.

Problem is that while cruising in corners, the inner wheel hops a bit, same when backing up - the inner wheel hops. Its like my AGA-welded cosworth.

Any ideas on where to start checking and what to do with it?

 

[badlite]

Sounds to me like you don't have a problem. It is just your sure grip doing what it is supposed to do.

 

[67 coronet]

drop out the third member and look at the spider gears or posi unit.if you are getting wheel hop it is either welded spider gears or a stuck lim slip unit.

 

[Dreadl0ck]

Sounds to me like you don't have a problem. It is just your sure grip doing what it is supposed to do.

drop out the third member and look at the spider gears or posi unit.if you are getting wheel hop it is either welded spider gears or a stuck lim slip unit.

I still don't get it - some say that sure grip is doing it's job and that it needs higher torque to start working as a limited slip, some say that it's stuck. Can anyone confirm that a sure grip will cause a bit of a wheel hop cornering in low speeds?

If this is the case I might replace the thing.

Thanks.

 

[Speedbird]

drop out the third member and look at the spider gears or posi unit.if you are getting wheel hop it is either welded spider gears or a stuck lim slip unit.

I vote for this. Don't ask me why .
Though I have seen dry clutch type units pop after extended highway driving, then around corners till they get fluid back in them. (Dana)

 

[Meep-Meep]

There is a factory procedure to check the SG unit in the way that you describe but with a torque wrench attached to the wheel or axle with an adapter. Excessive chattering might mean trouble so do have a look at the carrier.

 

[HawkRod]

In my opinion, it sounds like you have an issue. Regardless of the official test method, the inner wheel should not be chirping and hopping on a sure grip when driving the car.

 

[Dreadl0ck]

I was going through some of the left overs from another car I just passed away and found out I have a brand new Eaton Truetrac in the box it came with. That's the backup plan if I can't get the sure-grip to work properly.

Then I must confess for I have sinned. I have been tinkering about with a Ford. Please forgive me. Engine swap and new Quaife LSD in the rear so I'm not a bit worried about the Sure Grip issue. Damn it that this is my first old car so I have to ask all the questions. Thanks for helping me out though.

 

[62 Dart Convertible]

I had exactly the same inside wheel hop issue when I had crappy skinny tyres on car. I later put 275s on it and the problem went away.

 

[Dreadl0ck]

Meaty 295s on it already ;)

 

[Cornpatch MO]

IMO you have a spool in your diff.--Your sure grip clutches are set to tight--or you may not have sure grip additive in your diff. lube. I guess it may also be in the spider gears inside your sure grip unit............................MO

 

[MOPLUM]

I agree with most the posts here. Keep it simple, its sounds like you need to change out the diff lube with new oil. Make sure to add put in sure grip additive "hypoid" or the clutch pack wont slip. They will wearout real quick. Your tires may chirp around the cornres too. By the way your tires on a sure grip are supposed to turn the same direction when jacked up as well as not turn when one is on the ground. That is anouther reason I think you are just missing the sure grip additive. Its easier than pulling the diff. Might be all it needed.

 

[Sixgun]

diff problem

So, add the Mopar spec limited slip additive, and go find an empty parking lot.Go three full turns (circles) one way at full steering "lock" (like clockwise SLOWLY),then three full turns the other way (counterclockwise).In theory, this will force the clutches (if you have any) to accept oil and start slipping.If it does not work, you have some welded up sh*t or a spool or detroit locker (whee!) Hope this helps.

 

[66Satellite47]

Yea, sounds like it's got a Detroit Locker, VERY unlikely, broke spiders, needs "limited slip friction modifier", spool, maybe really bunged up clutches in the Trac Lock??