RowJ

Checked with Dana today, and my 'Bill of Materials' number (606708-2) says I have a Power Loc LSD in my Dana 70.
Thought I had read here that all 02's (and most 00's, 01's) were Trac Loc's?? (Maybe I misunderstood and this is just on the Dana 80's)??
Anyone know if I might have the stronger Power Loc limited slip?
Any 01 or 02 automatics know which unit they have?

Going to pull it soon and would like to order some parts, in case needed.

RJ

crobtex

Where did you get the "Bill of Materials' number (606708-2)"?

The tag under my hood says it's a Dana80 (hyb).

BigBlue

Might I inquire as to why you wanna pull it? I don't know what I've got but I do know that when I wanna leave two marks all it takes is a little bit of boost and the right application of brake and I'm leaving two marks behind me.

1stGen545

The autos had 70s and the 5spd had 80s in most. Most with 3.54 had power locks and 4.10 had track locks. Most but not all.

zulusafari

Interesting. My 01 has 42434 stamped into the back cover. I used to have a small tag hanging from a bolt, but I didn't see it there anymore. Does that number mean anything?

crobtex

The tag on mine just says to use limited slip oil.............numbers.

RowJ

I plan on restacking the clutches & plates...so they all work. As you probably know, Dodge only stacks 2 of the 5 clutches on each side...to avoid customer complaints regarding chatter in tight turns.
Did some testing, with one wheel on wet grass and one on pavemant. Found I get about 1 rev before 'loose' wheel grabs. When it grabs, it grabs hard. I would prefer to have a full LSD. IF there are 5 clutches/plates in there, I believe I'll use them all...as designed. A little chatter just tells me it's working.

RJ

RowJ

Manual Trannys have partial Dana 80. Autos a Dana 70. "BOM" is the 6 digit # that tells all about what Dana put inside. It's stamped (on earlier models) on the differential casing. Mine is on a stamped metal tag (strip) under two of the pumpkin cover bolts.
Also have the tag about LSD additive!

RJ

CTD NUT

RJ,

You might want to be careful about stacking clutch plates on your Plok....this is not a normal LSD that relies on a fixed amount of clutch preloading to determine the level of clutch holding power. On the Plok, the clutch preload is very minimal and ultimate loading is determined by input torque. You will find that the Plok is very sensitive to small increases in clutch preloading.

The whole idea behind the Plok is to run very loose and smooth when traction is high and will proportionally increase loading as input torque increases. Adding more preload over and above stock tends to make the Plok very grabby and compromises its normally excellent street manners.

For street use, I would suggest adding one additional clutch over and above stock when rebuilding.....unless of course you don't mind driving around in a grabby, chattery Plok - which I know some guys don't mind.

ddestruel

What you should have is the later version of the power lok…. Or so they call it. It shares more in common with the Trac lok and some books call it a power lok some call it a trac lok. in my book the only thing that resembles a powerlok on it is its bolt together case whichis where is all stops. The cross shaft is fixed in the housing so it cannot ramp up and add additional load to the clutch plates. With this later 98-2002 model all of your traction biasing is solely connected to the amount of preload on the discs. I haven’t been into one In a long time I always swap them out for an earlier model Power lok where the cross shaft can ramp up. That said IIRC you are correct and out of the 7 or 10 thin disks per side only one of them was curved ( so two total for both sides).

In some cases I remember several guys having success with removing one of the thin clutches and replacing it with an additional thick curved clutchon each side many times they would steal this from the old clutch pack as it was typically the thin clutches that were worn not the thick curved piece. I’ve also heard of guys keeping all the new thin clutches plus adding the two extra curves, and ive heard of guys throwing in two of the old thin (best looking out of the old set) clutches and two additional curves. Builder beware as you know the more stress you put on the side gears the more stress it puts on the housing and the cross shaft i dont mind adding a curve when you remove a flat disk but stacking in more disks than the stock pack can take scares me a little especially in our heavy truck applications. You’ll have to feel it out tailor it to your tastes, I wish I could offer more insight but ive avoided the newer diffs like the plague. Most of the guys out there who have done additional stacking in these trac loks use two longer bolts to compress the housing some when reassembling so they can get the std bolts started tehn they remove the longer bolts and reinstall the last two std bolts. Otherwise with the additional clutches stacked in there and or the additional curved clutches the housing sits too high off the base to get any of the bolts started threading in.

If it does ends up being a Power lok (but the last year of these was 1998) with the ratcheting (floating cross shafts) vs fixed then get a steel clutch pack for a D70 HD I don’t care what the book says they hit you for $180 on the d80 power lok disks and they are garbage, something like 14 disks and two curves and they have torque biasing grooves to soften them up. The old D70HD disks fit right in there are 4 curves and 6 flat steel disks for $60 +/- depending on who you buy from and if you want you can add one or two of the old curved disks inplace of a middle flat from the old clutch kit and add a little more pre-load. but other than that usually the powerlok when stacked properly which is flat-curve-flat curve-flat per side works pretty well you can also oppose the curves instead of having them both facing the same dirrection. if anything that would be my recommendation opose the two curves on each side that should add a little more grab for you or you can concave the center flat clutch or try replacing it with one of the old curved fromt eh original clutch pack but stay at a total of 5 per side. i have seen 6 per side using the ultra thin torque biasing disk as a 6th disk or a shim but im not a big fan of that

RowJ

Excellent info...Thanks. And what did cross my mind with our light rear ends was "be careful what you wish for..."

You don't feel the hard grab after one rev on the slipping wheel (with some serious torque build up) is a problem? My concern is drag racing launches.

RJ

RowJ

Great read...Thank You!
So I tell it's a Pwr Loc by the Oval hole (with the 'V') vs the round hole, right? I'm assuming the oval hole is what allows the 'float'?
(Sorry if dumb question....never been in there before.... all my knowledge, so far, is book learned.)

RJ

ddestruel

correct. if its slotted witha v its a p-lok if its fixed its T-lok

no dumb questions. shoot dana spicer considers the T-lok the service replacement for the p-lok ..... im not sure why

bust not going in half cocked then you'll really geta supprise when none of your parts fit.

camelracer

ddestruel,
I've been looking into putting a plok in my D80 and have found from this site and TDR that a modified D70HD will work. Do you know if the D70HD is a true plok or a relabeled tlok. Have you had any experience with the modified D70HD?

ddestruel

yes the D70HD will work i did a whole write up on it several years ago but it seems to be lost in info land.

get a D70HD powerlok carrier, chrystler is the only ones that call thier unit the P-lok when its not really. The D70hd has to be one equipts for an ABS tone ring. the ring and pinion split is the same have the ring gear bolt holes machined out to the same size as the d80 ring gear bolts and you are done. the d80 ring gear will bolt up the the carrier and the d800 and the d70hd share the same carrier bearings. dana hasent messed witht hte d70hd since it inception so you are safe. order it from randy's R&Pinion. After we figured it out with junkyard parts on my next truck i ordered one from them back in 99 or 2000 and though it took awhile to convince them, to machine out the ring gear bolt holes they did it and now i hear they do that as a option