2nd Gen Non-Engine/Transmission Dana 80 Questions: Please Help!

[SBillinson]

I bought a used dana 80 for a dually, supposedly with 180,000 miles on it. When I brought it home, I discovered I couldn't turn the axles. When I took off the rear cover, the caps were on wrong and the carrier bolts were rubbing against the left cap (the cap bosses were facing toward the center--the wrong way--and the carrier bolts were rubbing against them).



Well, I called the guy who sold the rear end to me and he told me he did take the caps off because he was going to part out the rear, but changed his mind. He said he never ran the rear with the caps on wrong. I believe him because (1) you couldn't turn the rear by hand and (2) he put new lube in and it was clean, like it was never circulated through the rear.



With the rear apart, I filed the bosses where the bolts were rubbing to smooth out the rough spots. I did this to remove any possible stress risers that would lead to cracks. The bearing and gears look good, but I am no expert on rear ends. I don't know how long these components should last, and I am really nervous about the guy who sold the rear end to me putting the caps on backwards (I'm thinking: what else did he try to mess around with?).



Now the questions:



1. Since the caps were on the wrong sides, and upside down, should I replace the carrier and pinion bearings?



2. If I replace all the bearings, should I also replace the gears?



3. Hell, while I'm there, should I replace the hub bearings?



4. Would putting the caps on backwards stress them to the point where they could crack (eventually) even though he never ran the rear with caps on wrong?



5. Should I have the caps checked for cracks?



6. Is there anything else I should be aware of?



I really don't want this rear to lock up on me. I tow with this truck and am converting my single wheel drive to the dually for some added towing stability. I am trying to make the towing experience a little safer, because I tow with my wife and kids in the truck. Locking up the rear at 65 mph with a 12,000 lb trailer in tow with my wife and kids on board does not appeal to me.



Any help about this decision would be much appreciated.



Thanks



Steve

 

[RACE427]

Steve,



I would re=install the caps the way they were suppose to be and torque everything to specs. Do not feel you will have any problems with these components. If something is wrong it will be noticable immediately with abnormal noises emitting from the rear. Just a thought. Good luck.

 

[NHouse]

I would also just re-install everything correctly and keep an eye out for leaks and noises at first. These rearends are extremely stout and problems aren't very common. When you get it in the truck, get out and put your hand on the cover after driving around for a little while, it should be warm, if it is hot, there could be a problem somewhere.



Nick

 

[MaxMartin]

Should not be a problem. If you want to check get a dial indicator and check the backlash by holding the pinion still (absolutly still) and see how much backlalsh there is. While every thing is unhooked, axles and drive shaft. Check the preload on the pinion bearing. Without a gauge just see if there is some resistance to turning by hand and it turns without any ratcheting. If you have access to red led or prussian blue, coat the ring gear and turn the pinion with a sleight load on the ring and check the pattern. Next turn the ring with a sleight load on the pinion. Motors manuals for trucks and many other manuals have the correct pattern you should see. Running it and feeling it to see if it is hot is relative. Hot you can't hold your hand on. if yoiu run it without a load and it is to hot to handle, something is wrong.

 

[MaxMartin]

damn, I just read my post. I cant spell.

 

[KevinSmith]

Run it . I`ve run Danas for years in various rigs and never had a problem. All I would do is reinstall it check the seals and bearings and use the standard oil in it.

 

[SBillinson]

Thanks

Thanks everyone for your responses.



The rear is definitely a stout piece. I looked at everything and all seems okay. I checked the run out and gear pattern. I just get real nervous about parts breakage, especially if it can be avoided. I imagine driving happily down the interstate, then--BAM!--broken rear-end and the aftermath. The irony is that I am going to the Dana 80 Dually for safety reasons. I just hope using this rear turns out the be the right decision.



By the way, how often should the bearings and seals be replaced?



Again, I appreciate everyone's responses.



Regards,



Steve

 

[RACE427]

Dana 80

If you already have the rear apart then I would replace all of the seals. The bearings, I would check the races for any nicks, gouges, scoring, bluing or real bad discoloration. The bearing races tell the true story about a bearing. Anything wrong with a bearing roller will show up on the bearing race. I am willing to bet that your bearings are fine. Dana makes one heck of a differential. Everyone I knew as a kid wanted a Dana 60 for drag racing. Much stronger than the GM 12 bolt. Hope this helps!