Have you tried doing a differential fluid change yet? Maybe a fill with new fluid will fix your issue. You can examine the fluid as well to see if there are any metal shavings or contaminants, which will give you an idea on the health of the differential.
Changed out the fluid when i went to change out the wheel bearings hoping they or the fluid were the problem. Proper fluid and the friction modifier were added to the correctly level.
However when I had the diff open I checked the backlash. Far too much play in the gears. I’m fairly certain it’s the pinion bearing that’s failed but in order to replace that I have to go through all the trouble of setting pinion depth anyway so I figured I’ll either do the full rebuild or just swap it out.
@mikeaf
Yeah I think the problem is the differential itself. Perhaps just swapping out the diff with a new unit is better than rebuilding the orignial. Unless you plan on using upgraded/high quality internals. Let's see what other members suggest on what to do.
I do appreciate the input. Thanks!
swapping the entire axle is definitely the easier and cheaper route. If you knew of a donor vehicle that didn't have axle issues, then that would be a good route. But with a unfamiliar donor, it's a craps shoot as you say. On the other hand, it can't get TOO much worse off than you already are. If you're lucky, you might be able to spin the wheels (at the boneyard or whatever) of the axle and get a sense of the condition. Heck, they may already have a collection of pulled axles that are already tested or they could throw it on some sawhorses for you. You might be able to get one for $500 or something.
If the swap option isn't available, or you don't want a used one, the you can try calling some shops in your area. Parts are going to be at least $1,000, and labour another $1,000 or so.
Appreciate the input. Axle swap is definitely easier. Quote I got was approaching $3,000 and the mechanic recommended a salvage axle as well. Those go for about $350 in my area if I pull it myself. Going out this week to see what I can find
I guess worst case if I get a dud is I can set the old axle on my work bench and rebuild it there as a weekend project.
Sounds about right to me. Oh and don't forget to grab one with the correct axle ratio and lug studs.
Appreciate the tip. It’s a 4x4. Wrong ratio would be a disaster. Hoping the pillar label and axle tags are still on the vehicles I’m looking at. But if not I can still get the specs from the VIn off the Ford service website.