What to Look For When Buying Used Rear Axle?

[19Walt93]

4.10's will help get your power back but I wouldn't spend an extra nickel to get 31 spline axles for a 2.5 truck. Traction Lok will help in snow or poor traction but when it breaks loose it will want to slide sideways.

 

[Basilius]

Is there a way at the salvage yard to know if the pinion bearings are bad?

 

[sgtsandman]

They will have an educated guess but will not be entirely sure. The is always a chance it will be bad.

 

[Shran]

Rotate the pinion flange. Note any noises, leakage from the seal, write it off if it has any in/out/side to side movement (it should ONLY turn.) You can also determine wear by turning the pinion back and forth just a hair, you will be able to feel what I would describe as a soft "clunk" which is the backlash between the ring and pinion. There should not be much rotational distance, if you feel like you're turning the pinion quite a ways before you feel the "clunk", there is probably a good deal of wear/lots of miles on it.

 

[Basilius]

I picked up the 8.8 31-spline axle (code V313L) for $150 and it seems to be in good shape. It's not bent, there are no broken teeth, the pinion flange only rotates (no in/out/side movement), and everything rotates smoothly. All that I've done so far is drain the gear oil and remove the drum brakes, but I'd like to replace the axle shaft seals and bearings, replace the drums with disc brakes, replace the brake lines (some are pinched/compressed), and possibly replace the pinion bearing and seals. I've watched some videos on how to change the 8.8 axle bearings and seals, but none of them have the same internals as my differential (there is no cylindrical cross pin to remove after removing the cross pin bolt in my differential). I'm also a first-time mechanic so all of this work will be brand new to me.
1. How do I remove the axles to change the shaft bearings and seals, since there is no cylindrical cross pin to slide out after removing the bolt?
2. Is it worth trying to replace pinion bearing and seals, or should I just leave it alone?
3. Is it worth trying to change the brakes from drum to disc?
4. When refilling the differential, can I pour the gear oil directly into the uncovered differential and then just replace the cover, or do I need to first replace the cover and only fill it from the fill plug?

 

[scotts90ranger]

That sticker isn't the axle code, that's some factory code that means nothing to normal people... The two tags on the diff cover bolts, one of them should say something like 4L10 88 on the lower row. I'm going to guess this is from a FX4 Level II Ranger? If so, those are somewhat of a rare breed and I'm not sure what you can do to the brakes, you might be able to put on Explorer discs which would be coming up with the backing plates, all brake lines and hardware and while you're there grab two passenger side soft lines, then go to a auto parts store and get two brake line fittings and cut the factory hard line where the Ranger line meets in the middle then flare both ends with the new nuts...

 

[Basilius]

Yes it's from a 2004 FX4 level 2 Ranger.

 

[gaz]

If your planning on maintenance free driving for a while and you have the time and money, use all new bearings/seals, fluid and brakes.

In regards to changing to disk brakes, depending on the intended use, you may not realise the difference, whereas when I changed from 9" drums to the 10" drums, it made a HUGE difference. By the same token, I despise drum brakes and I'm excited that it is do simple toadd them ..)

Only service it when properly installed through the service port.

 

[Basilius]

Should I also try to replace the pinion bearing and seals while the axle is out, or is that just asking for trouble? I don't think that the pinion seal was leaking and there is no wobble in the pinion flange, but the axle does have 300k miles and I don't know if any work has been done on it. Again, I am a completely first-time mechanic and this work is all new (and daunting) to me, but I'm willing to learn and put in the work to make improvements.

 

[Basilius]

Rotate the pinion flange. Note any noises, leakage from the seal, write it off if it has any in/out/side to side movement (it should ONLY turn.) You can also determine wear by turning the pinion back and forth just a hair, you will be able to feel what I would describe as a soft "clunk" which is the backlash between the ring and pinion. There should not be much rotational distance, if you feel like you're turning the pinion quite a ways before you feel the "clunk", there is probably a good deal of wear/lots of miles on it.

Also, prior to removing the brake drums, the pinion flange made a soft clunk and stopped when I rotated it back and forth. Now the pinion flange and axle shafts can both rotate freely (with no clunk) after removing the brake drums. This is normal?

 

[Uncle Gump]

It's most likely normal.

That rear end has the bigger 10 inch drum brakes... personally I wouldn't change them to disc. I would take a good look at the brakes and replace what needs to be replaced.

If that pinion seal isn't leaking... I would run it. It can be changed easy enough when installed in the truck. Before venturing into the pinion seal... educate your self. If you do it wrong it will ruin your day.

 

[Roert42]

It’s the best time to replace all the bearings, pinion and carrier included. I would replace them, but I’ve done it before and have all the tools

The pinion and carrier bearings are press fit. So it is a PITA to replace without a press and special bearing puller.

you could probably pull the carrier and pin and bring them to a shop to do the bearings.

The last concern would be that changing the bearings would mess up the gear lash and contact patch. This will cause excessive wear on the gears.

 

[sgtsandman]

If you replace the pinion bearing, you may need to reset the back lash and tooth engagement.

 

[Basilius]

What would be a fair price to have the carrier bearing, pinion bearing, and pinion seal replaced on this axle? I was just quoted $850 by a local shop and that seems high to me, especially since the axle is already removed from the vehicle and the oil is drained.

 

[don4331]

Local shop quoted me $500 a number of years back to do the same work you are requesting; as a result, I am running the same bearings.