So I'm trying to find a company here in Edmonton to take me on as a heavy duty technician apprentice and so far its looking like I might have to go up north where there is far more demand (imo). Anyways I noticed on the drive over that my truck was making a strange whining noise and vibration on deceleration. It was loud enough that I heard it over my system blasting slayer lol. So on the way back home, the noise is getting worse. Crap! I don't need scary noises now, or ever for that matter! So just as I'm pulling up to my house (no kidding, 10 feet from my driveway) the rear end makes this absolutely God awful howling noise and then the truck started to buck and kick like a bronc at a rodeo. Finally it stops dead and I get out and find my driveshaft laying on the ground and the nut bouncing off in the distance.

So far it only "looks" like I need a new rear pinion seal and and to put the nut back on and torque it down. But I'm wondering if my rear end is dead? I can't imagine it did anything good to it with all that bucking and whining going on. Towards the end before it gave up, it did make an awful shuddering of the whole truck when I came to a stop.


Any insight guys?

 

I'd definitely pull the cover off and see just how sharp those gear teeth are. Hopefully you won't find any chunks laying loose.

 

From the "sound" of it (no pun intended) and the fact that you drove it until it came apart, I'd guess the rear is trashed. But like 12valve said, you gotta open it up and have a look.

 

Never a good sign when the pinion nut comes off. Like the others said, pull the cover and check it out. If by chance the gears are still useable get a new pinion new before putting it back on.

 

my pinion bearing in my 8.8 in my f150 comes loose about every 4 weeks, i just crawl under the truck and pull the shaft and tighten it down and go about my business. just pull the pan, i would say the teeth are pretty ate up if the pinion fell into the rearend.

 

Well I got the cover off and not surprisingly there was a lot of metal shavings in the housing. I put pics of the damage up later, I still have to pull the assembly out of the housing and diagnose what exactly failed.

 

pinion nut back off and pinion fell into the case.

 

Ok so I got both of the caps off, the axles out but I still can't get the differential and ring gear out so I can inspect the pinion gear and clean the housing. I've never gone into a rear end extensively before (just change the fluid) so I'm pretty new. My haynes manual is pretty useless, it just shows a exploded diagram of a dana 60 with "dana 70 similar" next to it. I must be missing something here or is the differential pressed in fairly hard?

Any help is appreciated

 

The carrier in a d70 has preload on the bearings. You're gonna need to pry pound and hammer that thing out of there. Having rebuilt mine I'd recommend looking for a used axle and poke around your old broken one just for fun. I've got about 500 into mine and donated the labor to myself...prolly would have had over a grand into it if I'd farmed it out. There is a d80 in the classifieds for cheap....

 

Ok I got the differential out without much of a fight and it looks like I need the following:

-pinion shaft
-pinion shaft bearing
-pinion seal

The rest of the gears looked fine, just a few gouges on the housing for the limited slip, nothing to serious IMO.

Before I forget, which way does the arrow on the bearing caps point for each side? I can see that the caps and axle housing have different grooves for the bearings but I don't want to mix the sides up (this is why one should take pictures before tearing something apart)

Also what should I expect to pay for the pinion shaft and bearing? I'm going to call a few places tomorrow and get some quotes, hopefully they don't take me to the cleaners...

 

Man, that sucks. My truck has been making funny noises on deceleration lately too; I'm hoping it's U-joints....

Keep us updated, and if you have the time, you could make a rear diff how-to for us noobs that haven't torn into one

 

you are going to need a ring and pinion atleast, gman its your pinion bearing if its a low "rumble" on decel.

 

What Logan said. You can't mix and match rings and pinions, kind of like bearings and races. Unless you want to be on your back again in 6 months doing the same operation, I would strongly recommend rebuilding the rear. When I did mine I paid about 450 for a Dana rebuild kit. New R+P, shims, seals, bearings--the whole she-bang. By the time I was done, it would have made more sense to purchase a used rear. There are special tools and parts required to get the business done...it's a complete pain in the rear and I didn't save much, if any $$$

 

It is usually cheaper to find a good used rearend, by the time you buy the R/P install kit and the gears. And then you have to make sure the pattern is perfect.

 

you are probably going to need a case spreader to set that rearend up properly. you can get a low mileage rearend, maybe even a dana 80, for a little more and you dont have to mess with it.