I'm doing the bearings in the rear end of my '87 F150, as the pinion was loose when I got it, and after disassembly, I determined that the Ring and Pinion looked servicable enough (No wear on the pinion bearing surfaces, the tooth pattern looked fine, no sharp edges or pitting on the Ring/Pinion). I got the Pinion put back in, and the preload all set just fine (21 in-lbs of resistance, spec is 16-28 according to Ford, on new bearings), so I'm happy with that. Now, my issue is, I've got the new bearings put on the case, and I've loaded it back into the carrier, the teeth are meshed on the Ring and Pinion, and the original spacers I took out are back in the location I took them out from.

Now, when I go to torque down the Side Bearing caps (90-100 ft-lbs, according to things) so I can check the mesh pattern (it should be fine, as I'm rerunning old gears, so all the same shims are back in the same places, but It's still good to check, I basically can't move the ring gear once I've torqued them down.

What the hell am I doing wrong? As near as I can tell, the bearing races are seated down in the bores properly, and it looks to me like I've got the side bearing spacers seated back in far enough.

Obviously I've got something out of whack, anybody have any ideas?

 

Backlash must be too tight.

 

I'm aware that's whats going on, WHY is what I can't figure out. These are used gears, going back into the same housing. Yes, I might need to shim things, but with the spacers in the same place (There were no shims on the side bearings on disassembly, just the spacers), it shouldn't be possible, as these gears were running previously. It's not outside the realm of possibility that I got the spacers swapped left to right, I'll try swapping them.

 

Yes,assuming the pinion depth is EXACTLY the same as before, the pattern and BL should be good. The spacers you are calling, are the shims. Yeah,try swapping sides to see how that does.

 

X2 on side to side swapping the spacers, confused those myself before.

 

If you're sure you fully seated the new inner pinion bearing on the pinion and the new race in the housing then about the only possibility is that the carrier shims were swapped left to right.

 

Yeah, i know the pinion is right, the bearing preload is right where it should be.

 

I don't know if some PO had this thing setup wrong, or what, before I got it, but I ended up having to go get a shim kit, and move the ring gear .015" away from the pinion in order to get proper backlash and tooth patterning. I don't think I've ever had to re-shim gears that went back into the same housing they came out of....