2nd Gen Non-Engine/Transmission 00' Dana 80 to 02' w/rear disks?

[JaMan]

How hard is it to convert a 2000 Dana 80 to fit my 02' w/ a 80 and rear disks. Does the axle change out or are the axle ends different so the brake assembly will not transfer? I blew my spider gears up and went in and rebuilt it myself, but I'm no differential mechanic and now 1000miles later the rear grinds when I turn and the wheels are turning different speeds. Going straight the rear is quiet. It only does it when I turn like backing out of a parking spot.



I found a complete 2000 Dana 80 with same gears but I want my rear disks, so can they be swaped out easily? It looks like only four bolts and pulling the axle shaft.



What should I do?



Jared

 

[Alphacowboy]

What fluid did you put in the rear? Did you add antifriction additive? I am guessing you have the limited slip. If you didnt add antifriction modifyer when you filled it back up, the friction pads wont slip and you will essensially have a welded rear. Also, when you put it back together, did you put oil on all the friction disks as it went together? if not, that could also be part of your problem.

 

[JaMan]

I put limited slip fliud in the diff. but didnot put it on each of the disks when I installed it. It feels like the clutches since they only do it when they are at different potentials. I still have some of the old disks in the shop should I pull it back down and try to piece a clutch pack back together?

 

[DCreed]

axle tube ends are different, try alphacowboys advice first.

 

[Alphacowboy]

I put limited slip fliud in the diff. but didnot put it on each of the disks when I installed it. It feels like the clutches since they only do it when they are at different potentials. I still have some of the old disks in the shop should I pull it back down and try to piece a clutch pack back together?

yep, I would tear it back down. I didnt do that the first time I had mine apart either. Was very very tight. also, how did you arrange the disks/clutches?? did you copy the factory stack, or did you stack them differently? Factory is very mild, with very little actually limited slip. You can get it very limited slip if you stack them all every other. When you have it apart, you'll know what I am talking about. Think of it this way, the more friction pads, means more surface, means less slip. If I recall correctly, I think Dodge only uses ~4 friction surfaces. and there is the potential for 7 IIRC.

 

[Alphacowboy]

https://www.turbodieselregister.com/forums/truck-911-archive-members-only/139634-d80-issue.html

 

[JaMan]

The kit was from Randys R&P and they were ziptied together so I put them in in the order they were in. Amsoil 75-90 extreme duty oil and a full bottle of LS additive 8oz. ? The old clutches were looked pretty good to me so maybe I can salvage the whole deal. Will spend my time on my Diff instead of trying to swap. The axle tube ends are different huh?



Jared

 

[SMorneau]

Swapping the axle is pretty straight forward. The driveshaft should not have to be altered. All you need to do is remove the U-bolts and change axles. If you have a lift and a cherry picker you can raise the truck, remove the spare tire, go in from behind with the cherry picker, use a chain and a couple of bolts thru the shock mounts and it will come right out. I put mine back in by myself with this method. You may need new U-bolts (NAPA $15/each) and you might need a bigger master cylinder reservoir, or at least watch it regulary to keep it full. I'm not sure about the proportioning valve.



If you can live with your drums I would find a local shop and have an expert look at it; sometimes it is the way to go.

 

[BILLVO]

The kit was from Randys R&P and they were ziptied together so I put them in in the order they were in. Amsoil 75-90 extreme duty oil and a full bottle of LS additive 8oz. ? The old clutches were looked pretty good to me so maybe I can salvage the whole deal. Will spend my time on my Diff instead of trying to swap. The axle tube ends are different huh?



Jared

The synthetic oil is the problem. I have rebuilt mine 2 times and it is just the nature of the beast. The amsoil doesn't work with the new clutch material and causes it the chatter. If you pull it apart it will look like new. You can just put up with it or put new clutches in it and break them in with a dyno oil for a few thousand miles and then put in the amsoil This is the only way I have found to get around the chatter after a rebuild if wanting to run syn oil. There is something about the amsoil that will not let the discs wear in. I talked to eaton about this and they also said it is the synthetic oil that causes it not just amsoil. They had a bad problem with this issue when GM was filling everything with synthetic from the factory. They say the clutch material makers have not kept up with the new syn oil technology.



If you pull the cover off and don't see anything I wouldn't worry about it. It won't hurt a thing. Mine has chattered like a full locker for about 60k now and no issues other than the wife not liking it.



I also talked to amsoil tech and they only recommend their basic 80/90 for ls applications I can't remember the exact oil off top of my head but it the cheaper one. They said not to use the extreme duty gear oils.



On edit after reading the other thread. I tried to soak my last new set of discs over night in the friction modifier and amsoil the last time I reclutched it for the same reason and it did nothing to help. I still soak new clutches but in dyno oil and modifier now.



I have rebuilt several others since using the normal dyno oil to break it in for a few thousand miles then switch to synthetic. This has worked perfectly and had no noise or chatter issues since.