I have an 02 1500 with 4.7 and the 3.92 limited slip rear end. The truck has 117K and often shudders and makes some noise when starting from a stop. Usually this occurs when you are starting and turning at the same time. I had the differential serviced at 90K, and about 2K ago my service shop added another tube of the LSD additive. This did not improve things. I have seen from threads that some units take the 75W-140 lube over the 75W-90. Can someone advise which I should be using. I am wondering if my shop used the wrong lube, since the issues only started shortly after servicing at 90k. Also if the clutch packs are going, is this rebuidable. The Dodge dealer service manager told me over the phone that I was probably looking at $1600.00 in repairs. He said to try using the Mopar lube and additive first and if things did not improve to bring it in. When pull the cover is there a way to see of the clutch packs are worn? I also keep hearing things about snap rings that break. Is there a technical bulletin on this? Any guidance would be appreciated.

 

Nope, the LSD has a tendancy to explode, Chrysler knows it, but doesn't own up to it. You're lucky, you got 1,000 more miles out of your LSD than I did. The dealership was right, it could cost you $1600. The question is are you going to spend that money wisely, or throw good money after bad?

Find yourself a shop that does differential work, and put in a set of gears and a detroit tru-trac or auburn LSD. Yeah, it's money out of pocket, but it's money well spent on quality parts. I've got the Auburn, and the difference between that unit and the stocker is night and day.

Or you could go to Dodge and have them put in the same parts that failed, are known to fail, and will fail on you again in another 80-100k miles.

 

Do a search on here for Retaing clip or C Clip issues and there's a wealth of info on what your incorrectly calling "snap rings".
As for your problem, the Retaining clutch pack clips usually cause no identifiable problems when running. It's usually when you pull the pumkin, do you get the dreaded "pumpkin surprise" and find large parts of these clips hopefully stuck at the bottom.
Your problem does sound like either not enough lsd additive or more likely, your over the 15k service interval.
Pull the pumpkin and drop the oil as it needs changing anyway. Take lots of pics of the diff and post them up.
See what you find inside the diff.
If everything is OK, add new 75w 140 with the 4oz of Mopar LSD additive.
Drive in several tight figure of 8's to mix up the new diff oil and the additive, and see how you go.
Hope this helps?
Al.

 

Thanks for the info. I will pull the cover on Wednesday and post findings with photos.

 

If you find that the clutches are falling apart, you can buy new clutch packs for about $60 and rebuilt the differential. That is the cheapest fix. I just bought a rear axle on craigslist that needed rebuilding cause the clutch pack broke apart and the peices got caught in the bearings and ripped them apart, and cracked the ring and pinion when it locked up. It turned out to be a good deal for me cause I was going to replace everything anyway and I wanted a new gear ratio, but my point is, do something about it now because if they fall apart it can get ugly fast.

 

I agree I think the OEM LSD is ok as long as it is maintained and the CPRCs pulled. But with it grabbing like that my first thought was low fluid or friction modifyier. My Q is why did they have to ADD another tube of anti-slip fluid. Did you have a leak or were low? If you have full fluid and the syphoned a bit just to add some more anti-slip then they should have known right then and there something wasnt right. There is a ratio of oil to anti-slip that is needed and if you think you need to go way over than just to make it work then something is wrong.

However, if you can find someone to replace the clutches and pull the CPRCs and replace the bearing while it is apart and get all of that for a good price then you might wanna do that.

However, an Auburn LSD isnt but a few hundred. If you are keeping your gears then you dont have to worry about adding in that cost.

 

I appreciate the feedback. I picked up the Synthetic 75W-140 and Mopar additive this afternoon. The dealer wanted $30.00/Quart for the gear lube. I picked it up at Advance for $18.79/quart. However they said that their data base showed it should take 75W-90. Additionally the owners manual is stating 75W-90 lubricant. Can someone confirm the proper lubricant for the LSD. Again it is an 02 1500 QC 4x4 with the 4.7L and 3.92 LSD.

 

02 is listed as 75w-90 for the 1500 and 03 up is 75w-140. I don't think there would be any problem running the 75w-140 in the 02 though. On mopar parts sites the ring and pinion are listed for 02-05 as being the same.

 

AllData specs for a 02 4.7 with 3.92 calls for 75-90

2002 Dodge Truck RAM 1500 2WD Pickup V8-4.7L VIN N Copyright © 2008, ALLDATA 9.90 Page 1

Vehicle: Fluid Type Specifications
Fluid - Differential

Differential Assembly Fluid

A multi-purpose, hypoid gear lubricant which conforms to the following specifications should be used. Mopar Hypoid Gear Lubricant conforms to
these specifications.

Note: Track-lok and Power-lok equipped axles require a friction modifier be added to the lubricant.

Front Axle:..........The lubricant should have MIL-L-2105c and API GL 5 quality specifications Lubricant is a thermally stable SAE 80W -90 gear
lubicant.
Rear Axle:..........The lubricant should have MIL-L-2105C and API GL 5 quality specifications. Lubricant is a thermally stable use SAE 75W -90 gear
lubricant.
Front Axle - C205F

.

Rear Axle - 9 1/4 Inch

.

** With Trac-Lok add 148 ml (5 oz) of friction modifier.