Rear Drive Axle Removal

[navydevildoc]

Ugh... in my continuing bad luck streak, we were able to pull out the diff; but the main gears have rust on them from when it looks like water got into the oil (it had a real milky look to it when I drained it), settled to the bottom of the housing, and then rusted.

It's all surface rust... but I don't know what that means for strength issues. The gear faces all look OK.

So I now have to possibly add diff gears to my already long shopping list of new axles, hubs, seals, bolts, etc.

Anyone have an opinion? Would you try to brush off all of the rust and clean it real good, or get new gearing?

[JSBriggs]

What you want to look for is pitting on the contact surfaces of the gears or on the bearings.

Also look at teh splines of teh axle. Was there any spine wear, or points at the ends of teh splines where the blend into teh shaft?

If you have spine wear, the splines on teh side gears may be worn. If your spines went pointy, you might have a bent housing, which might explain the difficulty in removing the axle and the diff.

-Jeff

[SafeAirOne]

It's all surface rust...The gear faces all look OK.

If it were me, I'd just clean up and inspect the existing 3rd member. If there are no significant defects on the wear surfaces, I'd clean it and run it. If I were really concerned about it, I'd look around for a $50-$100 used/good differential assembly and have it standing by as a spare--They're easy enough to change and used ones are plentiful and fairly cheap--Just ask around.

FWIW, when I replaced the R&P on my front rover-type diff, the parts supplier gave me one with a tiny occlusion in one of the gear teeth. When I sent it back, they sent me a different one with a tiny occlusion in one of the teeth. These occlusions were probably larger/deeper than damage I'd expect from SURFACE rust.

[StX_Rovers]

Congratulations on getting it out!!! Now go celebrate.

If you are getting new hub seals and bearings Rovers North has a kit that is cheaper than the parts individually. When you are replacing the big oil seal in the hub, be sure to replace the seal race while you are at it. The piece on the axle stub where the seal rides is actually replaceable, which is a very nice feature.

For the future, another trick to get the diff loose is to use a floor jack under it to break it loose. Just locate it under the casting, crank it up a little and that usually does it, then lower it ever so slightly so the dowels don't bind, push jack and diff forward (backwards of course if working on the front axle) until the gears clear, then lower away. I usually put a couple of layers of cardboard under the area for two reasons. One reason is to catch the oil drips. The other is that if it does get away from you it is a softer surface for the piece to land on and reduces the chance of nicking a gear tooth.

The other thing to check for is that the backlash settings are all correct. The ring and pinion backlash you set with the side adjusters, and I believe in the spider gears there is a shim between the gear and the diff case that adjusts for their engagement. The ring and pinion backlash you can check without dis-assembly of the differential, you just need a dial indicator. I agree that unless there is pitting the gears are probably fine. The surface of the gears is hardened and the metal underneath is softer for longevity. You will be able to tell if the wear has gone through the hardening. Try to shine a light in and look carefully at the pinion gear teeth as it works 4.7 times as hard as the ring gear.

The floor jack trick works well for installation while you are at it. Of course, I imagine that shell you are holding in your avatar probably weighs much more than a Series diff so you will probably be able to put the diff in one handed but the rest of us mortals need assistance.

[scott]

if you're going to look for a used diff (3rd member) know that the front and rear are the same except some of the front may not have a drain plug cause the drain might have been on the axle housing (i think). the 3rd members from a rrc (range rover classic) also fit but their gearing is different so you'll have to replace both front & rear and you'll loose low end but gain cruising speed and you'll have to drill a hole for the guide pins that are on the axle housings. they are cheap. i've seen used 3rd mbrs go for about $50

[Tim Smith]

I don't think a little surface rust will kill you unless there is an obvious failure. Just clean it up as best you can and pack it back in there. Time to start putting money in the change jar for the spiffy new diff you'll probably start longing for in about a years time.

This is probably a good reminder to go through all of the fluids like front diff, swivels, steering box etc and replace with new. Moisture collecting in there is going to be a given for a truck that has spend some time sitting.