So a few months ago I blew out the wheel seal on my truck pretty bad, was pouring out the tube onto the ground like mad so I took my truck to the dealership as I was an hour away from home. They got me in right away, told me my pinion seal and transfer case output shaft seal were gone as well. $700 later they replaced all three seals, had them look at my differentials while there were under and they said rear was great, front was in need of a rebuild, which I knew anyways.

About 2500 km later I'm getting weird noises from the rear, the whine on decel noise, and fluid leaking out of the pinion. I decide to take it back and they refused to warrenty anything, claiming the diff blew and it's not their fault. Tried arguing but whatever, went home and went to swap axels out. That's when simple stuff turned into nightmares. I broke two sockets trying to get the driveshaft bolts out of the yoke, ended up having to grind the straps off. Had to wail on the wheel nuts on the side they worked on to get them off, even had to snipe the drain on the transfer case just to break it loose. They had to have torqued everything down to 10,000 ft/lbs.

Now after that, my question is; Is it possible some impact happy monkey did my seals and crushed the pinion bearings? I haven't had time to open it up and haven't worked on the internals of these dana 70's to really know what's in them. You can grab the yoke and wobble it all around in any direction. Does that mean more than bearings on these? Is it even worth trying to fix this one or just sell it off as a rebuild-able unit? Not in a real rush on this, just would like to know if it's worth investigating.

 

Most likely the pinion bearing was failing and caused the pinion leak. It's very common to replace a pinion seal and later determine a pinion bearing was the cause of the initial leak. Small amounts of play that rarely are detected by hand start a small leak after repair the bearing is preloaded to a used bearing value which likely speeds up the failure. No way I see that falling on the tech at the dealer. I have a feeling they most likely used red loctite on your u-joint straps, as do most shops. The bolts won't torque high enough to cause your issues. Had you taken it to a shop the likely would have used a torch and impact on those without another thought. However over/under torquing is an issue that's often seen in this field, it's mostly caused by the pay structure. For the most part it rarely causes problems and most techs are accustomed to the issue so they never mention it to the customer.

Sent from my SCH-I605 using Tapatalk 2

 

I can see that I suppose. I'm not trying to blame the dealership directly, it is a high mileage truck, just all the things together with such a short life on the seal had me wondering.

It's a good chance its just the bearings then, not the R&P? Will probably be a week or two until I can get to it to open it up.

 

It's likely going to need a full rebuild. Ofter when there's that much slop the pinion will make contact with the carrier. It'll also damage the Pinon and sometime the carrier.

Sent from my SCH-I605 using Tapatalk 2

 

Guess that's what I was hoping wouldn't be the case but thanks for the help! Probably going to end up with a 'wtf did I get myself into' thread later on when I try to tinker with it.

 

i just rebuilt my dana 80 this weekend took me two days and had to pull the entire axle because the center section wieghs 70lbs with a open carrier and as i put in a trutrac it was 82lbs kinda hard to lift and put in and out to get it right i would say if you have never done a diff dontlet this one be your first there really picky on the preload and the pinion nut is torqued to 500ftlbs and by no means easy to get of i actually used a bolt cutter to get mine off as far as the wheel nuts you shouldnt of had put that much into the wheel nut as they should of just put preload on the bearings and backed the nut off 1/4 of a turn then installed the locking clip ...

---AutoMerged DoublePost---

and as for the strap bolts they most lickly jacked the threads up pulling th yoke as that happend to me but they probably forced them back in and are way tighter then what should be going on i drilled out the holes i went to.4wheelparts and got strap kit that bolts from the back just take a u joint cap with you to make sure it matches

 

Wheel nuts (lug nuts) hold the wheels on,
Hub nut (also called spindle nut) preloads the bearings.
Make sure you prelube the wheel bearings AND Jack it up and let gear oil fill each side prior to driving it. This is actually one of the easiest to set up in my opinion. Pinion pre load is typically set with a 1/2" or 3/4" impact.

Sent from my SCH-I605 using Tapatalk 2

 

Well since this axel is now pretty much a spare I might as well try to rebuild it as it won't really be an issue if I mess it up. Can't learn unless you try doing it!

 

If you don't get your shims right and torque the pinion nut to 450-500 ft lbs it will fail I bought a torque multiplier to do mine and make sure your rotating torque is right that's how you set your preload for the pinion and yes I was thinking spindle nut not axle nuts those are supposed to be torqued to 145 -185 ft lbs

 

That's for the 80 tho isn't it? Isn't the dana 70 somewhere around 250? I have a decent 3/4" tq wrench for that part, it's the inch/lb one for setting the pinion bearing preload that I need to find. Most likely have to order it out of the states as no one in my area seems to know what tools are. Should have seen the fight with the parts guy to get a 2 9/16" socket for doing the hubs in the future. Have to order an entire kit, according to him 'They don't sell the socket individually anywhere in the world'.