AMC 20 PowerLoc Posi Discs Question

The powerlock unit was also used in early 10 bolt chevys , early olds & pontiac , mopar 8 3/4 . Some of the early units used all flat discs . The dished style puts preload in the unit , the flat ones don't have the preload ,they get loaded by the four spider gear assembly trying to ride up the ramps in the case. The dished one are load by the dished plates and get even more load from the same ramps . In my Rogue I put the dished plate between the flat and dished disc , gives double the friction area . Look at a view of the 8 3/4 mopar unit . What do you're old ones look like ,all smooth or galled?  I've never used any replacements mine are still the OEM discs.  I hope I didn't confuse you any more .  

Steve can you point me to your old post? Thanks. We saw what they were doing and didn't agree with it from an engineering perspective. The space may be taken up but the load is not.

I appreciate those who have posted. I decided I couldn't take the status quo on this issue as I know it is or will impact someone's rebuild in the future, plus I needed to replace an NOS (real) kit we used to build my rear recently. I will do a full writeup on this in a separate vendor section, but I wanted to conclude this thread on a positive note.

All but my thin plates were trashed from my rear, I could not re-use the thick dished plates; I could have used the thin flat plates.

I followed a hunch, and a note mentioned here about the 8 3/4 Mopar rear and hit pay dirt, and I learned a few things along the way. Long and short - the 8 3/4" rear Powerlok has the IDENTICAL disc plates as the AMC 20 Powerlok. And there is a reasonable cost source of the 100% correct kit available (cheaper than the wrong kit offered in the AMC vendor community).

I spent some time in email and direct discussions with the authority on 8 3/4" rears and who also has some knowledge of the AMC20, so I got even more info than I started out to find (always a good thing). Turns out the kit being sold in AMC circles is the wrong Dana 44 kit. We are lucky that the 8 3/4" uses these same disc plates. I ordered a kit and did a full comparison to the original kit. The only thing I could find was that the dished plate new was a little more "bellevilled" than the worn out original - not a problem. Everything else - dead on.

Picture of AMC 20 pieces (bottom) vs 8 3/4" Mopar (top):


Buy with confidence! $75 + $8 shipping
www.doctordiff.com
406-883-4772 (ask for Cass)

I will address a little of the rest of the 8 3/4 vs. AMC20 in a product/vendor review posting, but for now, there is no reason to mess around with any other kit out there. This is the best one, and at a great price.