Bill,
What damage did they do? It seems to me like they could wear down to metal, and maybe even wear doen some of the metal, but the worst thing that could happen would be the LS would not be as effective or not work at all.
What am I missing?

Thanks,
Chris

 

When the friction material is gone they lock and only give under great stress. A loud bang or banging will be heard on a tight turn. Eventually the spider gears blow from the hammering they have to take. This can cause the total destruction of the differential and possibly take out the pinion as well. Mine lost part of a tooth and with a little polishing it was still quite serviceable. The bearings through out were toast. If you have synthetic gear oil or the friction additive you should not be able to tell your Dana has a limited slip at all except by lack of single wheel spin.

 

Chris - you're not missing too much!

As long as you have 90W in the diff, you should be good to go, although the rear may act like it's open...

The posi Dana 80 on my '98 Ram leaked out all the gear oil through the pinion seal, unbeknownst to me, and the posi unit actually locked up (worn clutch plates actually melted together) during a non-stop run from TX to CT. Meltdown/lockup occured in TN, after I pulled over and refilled with 90W - the clutch packs on each side violently separated after another 100 miles, sending the truck across every interstate lane to the shoulder, and then the median a half-hour later. I drove the truck after that for another 1000 miles, spread over the next week - it drove just fine! However, the damage was done, and I'd just left for the run back to TX when the wasted posi unit exploded (literally) and blew one of the spiders right through the diff cover. Everything inside was shrapnel...
We shipped a new posi in from VA, reassembled the pumpkin, and have had a 100K happy miles since - and the rear is still tighter w/o noise/chatter now than when it was new.

My point is, it's tough to kill a Dana 80, so I wouldn't hesitate to do what you're planning if it was my rig.

 

Chris, unless you've been having trouble with the diff slipping, just do a stock refresh. These diffs work really well in most situations stock because the more torque you put into them, the tighter the clutch packs are compressed.

If left too long, the steels will cut the friction plates. This is one of the pics of my ugly mess.


There are pics in my gallery of the rest of the ugliness. I was probably only a few miles away from the same problem Bill mentioned. The clutch packs were worn so thin that the spiders and side gears were only touching out at the very tips. Thankfully I got 'er fixed before I started making repectable power.

 

OK, I get it. I'm gonna take this seriously, but plan to wait maybe 500 miles to do it, just need to get through drag racing and pulling seasons.
I have it back together now, but the speedo doesn't work. Checked and cleaned the tranny sensor, then cleaned and then replaced the diff sensor. Still no speedo. Neither sensor looked like it had been physically damaged. I have no Brake or ABS lights on.
The next step for me is to swap the tranny spped sencor with my 96, but that won't happen until tomorrow.

All ideas welcomed.

Thanks,
Chris

 

OK, all fixed now. It was blown fuse for my speedo controller.

Thanks for all the advice.

Chris