Rear End Shudder - LSD Lockup?

Discussion in 'General Discussion' started by shirleyjp86, Jul 19, 2021.

Car Parts
  1. shirleyjp86

    shirleyjp86 Member

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    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!
     
  2. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    Hey Ronnie, where are you??? This is right up your alley!
     
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  3. rottenronnie

    rottenronnie Well-Known Member Supporting Member

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    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: Jul 20, 2021
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  4. rottenronnie

    rottenronnie Well-Known Member Supporting Member

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    Working on differentials is not all that interesting (to me) but I'll provide info on what I think I know (based on past experiences). :)

    Cheers
     
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  5. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    They aren’t really very interesting but we like all your input! Thanks lol
     
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  6. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    Awesome info! I even enjoyed reading it!!! :cool::D
     
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  7. shirleyjp86

    shirleyjp86 Member

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    Thank you, Ronnie!
     
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  8. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    Isn't he just the best! Always helps and it always makes sense! Hoping you will have good luck with your issue!
     
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  9. rottenronnie

    rottenronnie Well-Known Member Supporting Member

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    Awwww Shucks.....;)
     
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  10. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    True!
     
  11. shirleyjp86

    shirleyjp86 Member

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    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?
     
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  12. rottenronnie

    rottenronnie Well-Known Member Supporting Member

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    75W-90
     
    Last edited: Jul 21, 2021 at 10:15 AM
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  13. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    I like it when peeps bother Ronnie!! Keeps his brain busy. He will live longer that way!
     
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  14. rottenronnie

    rottenronnie Well-Known Member Supporting Member

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    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...
     
    Last edited: Jul 22, 2021 at 7:44 PM
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  15. Wifey

    Wifey Well-Known Member Staff Member Super Moderator

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    Oh my!!! You better take a vacation!!! We can’t have that happening to you!!
     
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