Engine/Transmission (1998.5 - 2002) Make Your LSD Hook Like A Locker

[HVAC]

Recently the most successful sled puller on the west coast suffered a minor setback. That's right, he snapped off the left rear axle in the semi soft track at the NorCal Rally last weekend.

A buddy of mine had let us borrow his boggers since he had a smaller set on his modified truck currently. Well, I guess we found the traction we were looking for!!!LOL



This unfortunate situation sent us in a tizzy as we tried to locate replacement parts, upgraded axles, larger components, cryo treated stuff, kryptonite infused unbreakable space shuttle parts We found ourselves confused and flustered



One lil kernal that was gleaned from our search for drivetrain mecca came from our Cummins powered brother at Ring & Pinion Service in Sacramento. Jorgy, that's Erik Jorgensen actually, but who can resist calling him Jorgy! Actually I better refer to him as Erik to be on the safe side



He told us he could show us how to make that LSD hook like a locker. To bring you up to date we switched Chris's D70 for a D80 to gain reliability. In the process his locker in the D70 became spare parts although the new D80 was LSD. Erik showed us that the fiber plates and the metal plates are segragated within the D80 LSD section of the third member. If you remove the plates and stagger them one for one (one fiber, then one steel) the overall aggressiveness of the clutchpack is improved. Quite a bit as a matter of fact. We don't have much testing done on the "Red Warrior" yet (just got it off the stands an hour ago) but we will be observing how the modified clutch pack arrangement performs.



I found this interesting and hope some of you folks do as well. You will need to remove the diff cover, remove the bolts holding the caps on, then remove the bolts securing the axle flanges and pull them out about ten inches, then pry the third member out of the axle housing. Take the eight or so bolts out that hold the clutch bucket to the third member and pull the plates out. Then rearrange them one for one and reverse the process.

I recommend using the friction modifier to avoid the chatter and banging the clutches can develop when turning corners.

 

[tgbol]

Thanx for the info. I am courious as to how it works. I know You guys will put a real test to it and let us know.

 

[csutton7]

Yes Hvac is right about Erik--you can't go wrong taking your diff probs to him--nice big shop and friendly guys to boot---on the drive home everything acted just as before with the Detroit in my old deceased Dana 70--need to drive with Dana 80 some more to see if I get the chirp around corners that I would sometimes get--I did get on it once earlier today and everything felt very impressive in the way of accelleration and getting the power to the ground----thanks to HVAC, Jake, Brad and Erik for helping me get back on the road---



about the clutch plates remember if you do this yourself to put the bearing caps back on the same side and in the exact same position as when you took them off to get the 3rd member out--also it's important to mark the two case halves to insure you get them put back together in the same alignment-------chris

 

[Rob Thomas]

Chris, HVAC,



Lets us know how it really works, I'm interested as well. Question, are there any shims to worry about? Since the pinion wasn't touched, we should be able to R&R it without problems, right? Thanks



Later, Rob

 

[Sled Puller]

Mine was marked from the factory with a vertical "y" and the other side had a horizontal one.



Are you guys going to post ALL the secrets? LOL



Rob,

Mine went in and out with 0 problems, no shims to fool with. Just put evrything back where it came from.

 

[csutton7]

Rob---sleddy is right no shims to monkey with--just put everything back as it came out exactly, except for the plates that you alternate--I'll keep ya'll informed of my findings--chris

 

[Rob Thomas]

Thanks Gene and Chris,



Damn, another reason to break-out the tools.



Gene, Speakin' of secrets, do you wanna disclose any others? I just pulled my first sled last night, and I sucked, my fault tho, wrong gear selection. My freind Dave (the guy with the biga$$ golf cart in Muncie, who also is another Mitchell junkie) won the pull, via full-pull in the 8,000# diesel class. (250' track) Paid $125, not bad for his first win.



Later, Rob

 

[FL70CAT]

Sounds like you set them up similar to how MOTORCYCLE clutches are... ... ... ... ... ... ... ... ... interesting mod!

 

[HVAC]

Multi Disc Clutch Pack

Your correct FL70Cat, just like a motorcycle clutch. It's also similiar to a clutch pack in an automatic transmission.



The metal discs dovetail into the outer housing or bucket that contains the entire LSD section. The fiber plates have teeth on the inner diameter that mesh with the splined center hub. If the two cylinders, inner and outer hubs turn at different rates, one wheel will turn slower then the other. Vice/versa, when cornering one wheel will want to turn slower which slips the clutches in the clutch pack.



Knowing how the clutch pack works you can see that when staggering the plates one for one you develop the maximum holding force/friction area possible. This holding capability is what resists the forces the wheels are generating as you round a corner. When all the metal plates are on one end and all the fiber plates are on the other, your only have one set of plates (minimum surface area) providing frictonal opposition to control spinning the LSD.

 

[Sled Puller]

Ya, here is a secret: Ixnay on LS additive. You don't want them to slip, remember?



Big golf cart- if I remember right, that dude was pretty big also. hence, the need for 35" tires on the cart, eh?





Hey, how many plates did you guys have?

 

[Chipstien]

Oh man....

One more project to do to my truck.

 

[csutton7]

I think there were 9 plates---chris