Differential question

[Cyclop3000]

Hey all. I've taken apart both my differentials to do the 4 gear spider mod. Everything is perfect in the differential case and both sides spin very smoothly, but when I mount the differential in the bulkhead and spin the bevel gear manually (the one that leads to the transmission), the differential turns very smoothly 3/4 of the way, and in the last 1/4 it's a little harder to turn and I can feel the gears grinding on each other. Then it keeps going smooth again...

Everything is greased up and looks fine, I'm not sure if it's normal or not...I didn't do that test before taking it apart. Bearings were all tested and all workfine, and it's doing it for both the front and end bulkhead so i'm thinking it's not something wrong with the gear or bearing. I don't think it's hard enough to turn to prevent the transmission from turning it, but manually you have some resistance.

Can anybody please tell me if it's normal or not? Any help would be appreciated, before I put the rest of the truck together.

Thanks!

 

[olds97_lss]

You might want to check and make sure you have the bearings fully seated on the pinion and output shafts from the diff.

Also, you may want to take the diffs out, loosen the ring gear screws a few turns and press the gear into the cup by hand a bit, then tighten the screws in an X pattern to make sure the ring gear is sitting flat against the cup.

I've done that before and got the ring gear uneven with the cup. I ended up with a diff that was ok for about half the rotation, then would bind quite a bit on the other half.

 

[Cyclop3000]

Thanks for your reply olds. I actually re-opened it up earlier today and checked those two things, and all seemed to be fine. I did screw the diff in an x pattern in the first place, but checked to be sure. Once I got it back in the bulkhead though, I pried the differential away from the bevel with a flat screwdriver. I felt the diff move and after that it was smooth all around. So it seems like there is some play between the diff and bulkhead, which I think explains it.

I'll leave it at that for now and once i'll have a few tanks in the new engine (as soon as the weather gets better...still a lot of snow here), then I'll take it apart to have a look at the gears and see if it's still in good shape.

Thanks again!