My rear axle gears have wear where the ride in the differential assembly, the left having .020 wear. The differential hole itself seems correct at 1.812" I.D. The MTFCA video says to turn down the gear bearing surface and use a steel bushing. Any tips for doing this?
Use Brass, or Bronze, steel will gaul.
I don't know if you mean turning down the shoulder of the gear or enlarging the holes in differential carriage. If you mean the latter, its been my experience that bushings pressed in the diff holes will, in time, spin. Perfecto used pins to hold the bushings in the bell where the gear shoulders ride and they still worked loose. A better fix is to weld up the holes and machine to the correct size. I agree .020" is a bit of wear but I've seen worse. I bet if you simply put it back together as is, you'd never notice anything in operation.
Thanks. Fred Houston on the MTFCA video says to turn down axle gear shoulder and put a steel bushing there. Glen Chaffin, in the Rear Axle Guide, mentions .010 wear as the max, but doesn't say how to fix it. If a repair is needed, I'd like to do it while it's apart.
I would just find better gears. They are plentiful.
That would work, Stephen. I know they're not made new, but maybe I can find a good original.
The gears wear very little compared to the cast iron differential housings. Just replace the housings. There are many to choose from. I have probably 50. Good ones are $100.00 a pair. You can find them much cheaper at the swap meets
I believe the rear axle gear shoulder (bearing area) should be 1.807". What should the I.D. of the diff. housing be (where the gear runs)? That is, how much play is recommended?
Yours is a good question. If everything were factory new I would suggest .006". But with the distinct possibility that your housings are no longer in alignment, more clearance is needed. Eg bent tubes, sprung pumpkin. I've lived with clearance in the 12 to 16 thou range without a problem. Closer is not necessarily better with rear ends.
My NOS Ford parts measure as follows: Gear: 1.807-1.8075. Housing: 1.8095-1.8100. That's 0.0025 clearance. I think anything up to 0.010 will work just fine.