2nd Gen Non-Engine/Transmission LSD is a one-wheel-wonder !

[trqmnstr]

Hey guys, I just recently bought my truck equipped with 3. 55 and LSD. Yesterday, I got in the smallest amount of mud and was slingin one rooster tail. I haven't checked the fluid yet but will low fluid cause the LSD not to work or is my LSD just worn out with 150K on the clock? I think it's possible that the diff fluid was changed without adding a LSD additive. Will that cause it not to grab? Any thoughts? Thanks

 

[Got Smoke?]

With no LSD additive it would cause the unit to be really grabby until it just totally destroyed the clutch packs.



At least that's my understanding of it... . somebody correct me if I'm wrong.

 

[Gary - K7GLD]

https://www.turbodieselregister.com/forums/search.php?searchid=334282

 

[trqmnstr]

Hey Gary, the link on your post doesn't go to anything!

 

[trqmnstr]

To the top

 

[Straight6Jeff]

With 150 k on the clock, your limited slip is probably just toast. You could try to dump teh fluid, spray the whole unit with brake-kleen to try to clean the clutches, and refil with a good dino oil. Only add lsd addative if the unit is grabby. Or you could dump the fluid, pull out the carrier, and rebuilt with new clutches and plates. A rebuild kit runs about $110. You can restack the plates ina n order to give you more bite, but there is a line between a tight lsd and a spool... I ended up with a spool. If you rebuild, it is advisable to use a good synthetic, and also replace the carrier bearings while you are in there. It is not difficult to do. I ended up putting in a Detroit locker. A detroit is not bad on teh street or on ice if you drive with respect to the detroit.



My lsd stopped lsd-ing after about 2k miles.

 

[chrleb1]

I had 250,000 on my old truck the LSD worked fine. You might want to check and see if someone swapped rear-ends and put a open diff in there. Its been done before. Jack up the rear end and then turn the tires with the truck in nuetral. If the tires go the same way, then that means you have a posi but just worn. If they go opposite, you have a open diff.

 

[trqmnstr]

To the top

 

[Alan Reagan]

On my 01, the LSD didn't work right until I went to synthetic. With synthetic, it worked like it was supposed to and I didn't have to use the friction modifier.

 

[JFitzgerald]

The LS in my '00 works well. There's 125K on it. I can tell it's there on turns, but it's not annoying at all. What LS additive is recommended? Any better than another?

 

[JHerrlich]

I believe the LSD is only rated for about 200 Ft/Lbs. When you jam more than that at it, it slips. Kinda useless on our trucks, huh?

 

[trqmnstr]

That doesn't make much sense to put a 200 ft/lb diff. on a 450 ft/lb truck, does it?

 

[JHerrlich]

That doesn't make much sense to put a 200 ft/lb diff. on a 450 ft/lb truck, does it?

The '01 service manual states that the Trac-Lok should let the tire differentiate between 30 and 200 Ft/Lbs of torque. Any less or more than that requires service.

 

[Gary - K7GLD]

"That doesn't make much sense to put a 200 ft/lb diff. on a 450 ft/lb truck, does it?"



BACK to reality, one more time, as stated further up in this thread:



These are *LIMITED SLIP* differentials, NOT locked differentials - they are designed to HELP equalize traction in unequal traction situations between the affected drive wheels. To do that, some means of differential slippage is designed into the differential to prevent it from ripping itself apart in turns on normal road surfaces.



I've tested mine with one wheel on ice, the other on gravel mixed on pavement on an uphill grade - sure. the wheel on ice still spun, but enough drive power was still available to the other rear wheel to easily move me up the road - and THAT is about all you can reasonably expect from this type LSD - if you really need more, then a locker is what you should look into.

 

[Alan Reagan]

The LS in my '00 works well. There's 125K on it. I can tell it's there on turns, but it's not annoying at all. What LS additive is recommended? Any better than another?

In my 98, I tried some aftermarket additive from NAPA. Don't remember the brand, but I do know that it didn't work.



The best I've seen is that from the dealership.



As I said, when I switched to synthetics in my 01, I didn't need additive at all.

 

[Chris N5CWM]

Mine chatters a little in turns at slow speeds. The other day I was pulling my boat up the boat ramp, and the right rear tire was on slick green slimy stuff over concrete, the left on wet concrete. I made it up the ramp fine but I could tell the right was spinning some. I'm sure if it were a standard open diff that I would have had to use 4 WD.

Sometimes when mine chatters and I have a passenger in the truck they ask me what's wrong with my truck. Guess I need to add a little more additive to what I've already put in there.