differential rebuild gone bad, urgent

Alternate Plan B: Hertz, Enterprise, Thrifty, Dollar, etc.

Good luck!

Did you use the steel service shims instead of the cast iron factory shims? Properly set for backlash and then added shim thickness to increase bearing pre-load, it shouldn't take all that much to drive the shims in with a brass punch straight and square. Lopsided ain't good.

You marked the bearing caps before disassembly, right, and put them back in on the side they came from, right? You pressed the carrier bearings on with a press and don't have 'em backwards, right? < > versus ><

Absolutely NOT! I've done dozens and dozens of Ford 8.8's without a case spreader (yes, I have one).

Smaller? it's either adjusted correctly or it isn't. Add shims to each side until there is no side to side slop while maintaining the backlash that was measured before disassembly (you did measure the backlash before you took it apart, right), once you have the backlash correct and no side to side slop, add about .004"- .006" more shim to each side, sandwich the thin shims between the thick shims, line 'em up and drive 'em in with a soft faced punch (brass or aluminum).

exactly what i needed to hear. i dont have a guage to measure backlash with :-/ so im trial and erroring with grease and looking at the marks the pinion gear makes. finally, finally, i went into work and got a pry bar, well a gentle one. i got it out, and now im using the shim kit (rather than the factory ones). about to go put it in now, i took

nope, didnt mark which was which, when i got the caps off, it fell out and i was more concerned on catching it than marking caps :-/ however, the right cap has a grove all the way around it, that matches with the differential case that the left doesnt, so i assume thats correct.

as for the factory shims.... i measured the little gap that is at the end of the axle tube with a caliper, and compared it to the discolorati> In article

While backlash does effect gear contact pattern, it still needs to be measured with a dial indicator. It should have been measured -before- it was taken apart, and then backlash set to

-that- dimension so that the gears don't chip. If backlash is too tight, the gears will overheat and fail.

By "shim kit" I hope you mean an actual set of shims from a rear axle overhaul kit.

You should have put witness marks on the caps before anything was touched.

I wouldn't assume that... I think the best course of action at this point would be to torque the caps back in place without the differential and then feel the parting line where the cap meets the axle housing, then switch them side for side and compare.

Glad to help.

i managed to start it over with a new shim kit rather than reusing the stock ones, and so far it looks beautiful, and everything is going much smoother. my only question now is, how do the shims stay in place? the cap that goes over the bearing doesnt cover the shims

aarcuda69062 wrote:

Friction. The total width of the carrier assembly, bearings, races and shims will be wider than the distance between the axle tubes where they fit, that's where the bearing pre-load comes in.