Dana 25/27 Powr-lok tech assistance please....

[Jordan]

I am installing a Dana 27 powr-lok carrier w/ Dana 25 spider gear set into a 1952 M-38 Dana 25 front axle. Apparently, in order to make this combo work, I have to have an adapter from Herm the Overdrive guy, which I also have. In fact, Herm assembled the hybrid powr-lok for me.

Here is the issue: With the Powr-lok installed and shimmed as far to one side as it will go, I still have .060 backlash between ring and pinion. Way too much. Turns out, I also have about a 1/8" gap between the two Powr-lok case halves. The literature says that gap ain't supposed to be there. One guy told me if the two halves are not bolted together tight, it will grenade. Herm says there is nothing wrong with it having a gap.

However, if I remove (1) tabbed clutch plate and one non-tabbed clutch plate from the cluch pack on one side of the Powr-lok, the two case halves come together nice and tight and, I can now shim away the excess backlash. Also, I had already removed the "dead plate" from the clutch pack and still had too much gap between case halves. Even with the dead plate out (per instructions) I could not close the gap between case halves and could not shim the excess backlash away. Only with removing two plates can I make everything fit.

So here is the Question: Will the Powr-look still work fine with less than a full complement of clutch plates on one side? I did not remove the bellville plates.
Thanks,

Jordan

[danrothe2001]

I agree that the two case halves should go together tight or they will work back and forth in operation and break. I am not familiar with his product but I did visit his website. It appears that all he is doing is using special carrier bearings due to a difference in diameters in the two cases and a ring gear spacer as apparently the flange is in the wrong place. Are you using the spacer? I have never seen a factory limited slip of any brand use a different number of clutches on each side. If they are now equal he probably installed one to many. If they are uneven maybe they are made to thick. Now for your question of will it work. A limited slip like a Power-Lok can be tested by holding the pinion gear and using a bar to turn the axle. I do not have a manual with the actual torque available, but I believe that it is on the order of 50 to 100 lbs. You should be able to turn the wheel forward with reasonable pressure on the bar. You should not be able to turn it backwards. This is due to a ramping effect in the Power-Lok that reduces clutch pressure and lets the outside wheel overrun on a corner. If you cannot turn it forward it will act like a locked axle and be impossible to turn. If you can turn it backwards it will not function as a Power-Lok. I have no personal experience with this but have been told that even with a Power-Lok you will have trouble turning. Hope this helps.

Dan

[Jordan]

Thanks Dan. There is a function test I could do---if I had a running engine (still assembling that!). I have some original spec sheets on the Powr-lok and I have the correct number of plates, but with the correct number in, the assembly is too long, as stated above. I think I'll give West Coast differentials a call on Monday, or maybe even Dana/Spicer.