putting pinion back

1930artdeco

Well-known member
Is there a trick to getting the pinion gear back into the diff of a 57 9"? I tried and ran out of shoulder steam to hold it up and wiggle it in. I assume you need to rotate it so the gears mess.

Thanks,

Mike
 
When you removed the pinion, did you notice any rotation as it came out? You would have to gently rotate it in the opposite direction slightly to get it to mesh with the ring gear.
 
Thanks, no rotation that I remember. I didn't think there was anything special but I thought I would ask just to be sure.

Mike
 
You would have to slightly rotate the pinion. You probably noticed the pinion gear teeth are cut in a spiral direction, so you have to basically "screw" the pinion back into the ring gear in the spiral direction.

Most people don't realize this and many will argue, but the ring and pinion should be marked before disassembly so the pinion contacts the same tooth on the ring gear when you reassemble them. The reason is that there are "hunting" and "non-hunting" gear sets. The hunting gears never contact the same teeth in one revolution of the ring gear against the pinion. The non hunting gears do contact the same teeth of the pinion per revolution of the ring gear. It's not as critical on the hunting gears to reassemble them as they were. However, the non-hunting gears can end up with a whine because the same pinion tooth will always contact the same group of ring gear teeth
 
Craig, that would depend on the gear ratio as to hunting or non-hunting, correct? The teeth on the ring gear would be evenly divisible by the teeth on the pinion to be a non-hunting type.
 
I recall when I first started my old man showing me the "timing marks" as he called them on a 9in ring and pinion set we were replacing. Marks were a line on the pinion and a mark on the ring gear and to mesh them together when installing the ring and pinion.
 
I have no idea if I have a 'hunting' or non 'hunting' axle. It is the original 3.56 axle in my wagon. I didn't know about these axles so didn't mark them and there is little to no wear since the mileage is so low-less than 50K. If it is 'hunting' and there are marks where would they be?

Mike
 
I would use a few studs to line up the shim and housing, lube up the O-ring and housing for a good slip fit. If the O-ring is new it will take a bit to get it pushed in. And yes the pinion will turn just a bit going in.
 
As CrownVic55 mentioned, on a non hunting gear set, the ring gear tooth count will be evenly divided by the pinion tooth count, for example a 35 tooth count on a ring gear divided by a 10 tooth pinion equals a ratio of 3.50. Since yours is a 3.56 ratio it is a hunting gear set and most likely won't have any noise whether or not you can reinstall it as it originally was.
The factories used to paint a mark on a tooth on the end of the pinion and 2 marks on the ring gear, 1 on each side of the marked pinion tooth. It's hard to see unless the 3rd member is out of the housing
 
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