68 442, Rear end is a TO code posi, 3.91:1 gear.

Last night my rear diff failed. When starting out from a green light at about 1000rpm I heard a crack in the back end. Suddenly no forward momentum. I was not launching the car at a high rev.

At the time I thought I might have had the drive shaft fail but it's intact.

Hence, a tow home.

With the wheels in the air - spinning one wheel or the other does not turn the opposite side.

I'm not sure whether it's a problem within the diff or perhaps it's a broken axle.

Here is my question:
I have another complete rear end - R2 code open diff with I think a 2:56 or 2:78 gear.
Do they use the same axles?

thanks Ben

 

No. Your 1968 TO rear has 31 spline axles. The R2 rear end has 28 spline axles.

 

Sounds like a busted spider gear.

 

i WOULD ALSO GO WITH THE SPIDER GEAR...Usually lack of maintenance and the unit clutch too loose and the spider gears had too much backlash between teeth so they tipped each other and not more teeth...BUT we could be wrong. Your going to have to open the rear no matter what so DIG IN...

NO 31 spline spider gears either... You could be in for some MAJOR money here.
31 spline posi units are not as popular as 28 spline ....

Jim
J D

 

Well I have removed the cover and drained the fluid. No bits and pieces at the bottom of the housing but I do have a broken axle, passenger side.

Are these 31 spine axles available? should I consider replacing both at once?

Help, and thanks Ben...

 

Just order replacement 31 spline axles from Moser. New and stronger. No worries on getting screwed paying for a used axle that could be bent or bearing surface ruined.

 

Some times they will not just take the order unless you have the specs.

Shoot me a PM we can get them ordered if you need as i have ordered them before.

Take care, Jim
J D