Rear End Shudder - LSD Lockup?

shirleyjp86

shirleyjp86

Active Member
Joined
Jun 11, 2021
Messages
70
Reaction score
109
Location
Lavonia GA
Hey guys, in a previous post I had mentioned a stutter/shudder at low speeds (0-15MPH.) I've heard U-joints or the 2-piece driveshaft's "carrier bearing" as being possible causes. However, before I go disconnecting the driveshaft or any other heavy-handed task, I thought I'd see what you all thought about the LSD possibly locking up, due to low fluid or due to the "slip additive" fluid being worn. A lot of guys with quad-cab HEMIS seem to have this issue on older trucks with old, dirty diff oil. I'm sort of leaning to this being the cause myself, because this shake is even worse if im taking off with the wheels turned. All of that being said, how difficult of a job is draining/filling the diffrential? Any input is appreciated!
 
Hey Ronnie, where are you??? This is right up your alley!
 
Yes, particularly when you are asking the Limited Slip unit to work (when going around corners) can it show issues. The clutch pack won't slip smoothly when its stuck in a catch-and-release mode like it may be now.

I went to the Dodge dealer for the additive and lube.

The Dana 60 (yours) has both a drain plug and a filler so a suction gun isn't needed.

Pull the drain plug and have a look at the magnet. Hopefully it has no metal stuck to it (or very little). If it looks good then after the fluid has drained out, replace the plug (snug but not stupid-tight).:

Put the additive in first (use gloves as the stuff can burn skin), then using the handy dandy filler tubes that come with the squeeze bottles, keep squeezing and approx. 2.5 L later, it will be full and will start to run out the filler hole. Replace that plug.

Go for a drive and give it a bit of time to appreciate all of your hard work. Hopefully this will solve the problem.

It is worth a try as unlike servicing our automatics when they have issues (fluid, filter and band adjustments), changing fluid in a diff can actually work.

If it still shudders, the posi, limited slip or whatever you like to call it, is best replaced as a unit. Around $500 or so for the posi unit plus labour to tear it all apart.

Good luck.
 
Last edited:
They aren’t really very interesting but we like all your input! Thanks lol
 
Awesome info! I even enjoyed reading it!!! :cool::D
 
rottenronnie said:
Yes, particularly when you are asking the Limited Slip unit to work (when going around corners) can it show issues. The clutch pack won't slip smoothly when its stuck in a catch-and-release mode like it may be now.

I went to the Dodge dealer for the additive and lube.

The Dana 60 (yours) has both a drain plug and a filler so a suction gun isn't needed.

Pull the drain plug and have a look at the magnet. Hopefully it has no metal stuck to it (or very little). If it looks good then after the fluid has drained out, replace the plug (snug but not stupid-tight).:

Put the additive in first (use gloves as the stuff can burn skin), then using the handy dandy filler tubes that come with the squeeze bottles, keep squeezing and approx. 2.5 L later, it will be full and will start to run out the filler hole. Replace that plug.

Go for a drive and give it a bit of time to appreciate all of your hard work. Hopefully this will solve the problem.

It is worth a try as unlike servicing our automatics when they have issues (fluid, filter and band adjustments), changing fluid in a diff can actually work.

If it still shudders, the posi, limited slip or whatever you like to call it, is best replaced as a unit. Around $500 or so for the posi unit plus labour to tear it all apart.

Good luck.
Click to expand...


Thank you, Ronnie!
 
Ronnie, I hate to bother you again, but the manual calls for Mopar SAE 90W - I can't find straight 90 weight gear oil anywhere online. What are other SRT-10 guys running, or what do you suggest?
 
rottenronnie said:
You must have forgotten about that scene in Return of The Jedi when Yoda gets so tired of answering Luke's questions that he just dies; his body then slowly disappears.

It can happen to ANYONE...
Click to expand...
Oh my!!! You better take a vacation!!! We can’t have that happening to you!!
 
*UPDATE*

I drained and refilled the diffrential with Mobil 1 75W-90 gear oil, took her for a 10 mile drive and even did some figure-8s in a church parking lot to get the clutches going - no dice. It's looking like it may be the carrier bearing after all. I noticed while I was under the ol' girl that the front and rear halves of the drive shafts were at remarkably different angles. The truck appears to have been lowered 2" in the front and 4 or 5" in the rear using some unknown kit. Does anyone know what angles the two shaft halves should be at?
 
Last edited:
shirleyjp86 said:
*UPDATE*

I drained and refilled the diffrential with Mobil 1 75W-90 gear oil, took her for a 10 mile drive and even did some figure-8s in a church parking lot to get the clutches going - no dice. It's looking like it may be the carrier bearing after all. I noticed while I was under the ol' girl that the front and rear halves of the drive shafts were at remarkably different angles. The truck appears to have been lowered 2" in the front and 4 or 5" in the rear using some unknown kit. Does anyone know what angles the two shaft halves should be at?
Click to expand...
I put a McGaughy 2/4.5 lowering kit on mine, you might have the same. Not sure the degree of tilt, but I have no issues. I also replaced the carrier bearing, and the U joints I went with Spicer.
 
AMS3 said:
I put a McGaughy 2/4.5 lowering kit on mine, you might have the same. Not sure the degree of tilt, but I have no issues. I also replaced the carrier bearing, and the U joints I went with Spicer.
Click to expand...

I'm just a back yard mechanic, even on my best days. Do you think U-joints and the carrier bearing are something a dude like me could handle? I'm assuming things could get ugly if done incorrectly.
 
You must log in or register to reply here.

Latest posts

Support Us

Become A Supporting Member Today!

Click Here For Details

Random Media

1498.jpg
IMG 3651
SINGLE TURBO
EJH
Back
Top