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Differential oil additive help

6K views 11 replies 5 participants last post by  M9ADE3 
#1 · (Edited)
I have been searching the past two days about this matter and screen shot what I found useful. My question is which Mopar LSD oil comes mixed already with additive ? So far found 2 posts mentioning this part number already additive in the bottle 68083381AA went to the dealer and the guys told me its not you need a bottle of additive !!!!! found fnkychkn post also that this part number 68232948AA Supersedes to 68083381AA. please lets put an END to this matter.

Found a thread a guy has the same issue rubbing/groan noise we all know it has TSB I already did it 2 years ago and now its back again haven't drove the car more than 7k miles the past 2 years thats confusing me more so i'm going to drain it and fill it again hopes it fix the issue, back to the subject that guy mentioned the dealership did him the TSB and used this part number 68083381AA but they used a bottle of additive and they suppose not if its true mixed and his car has the noise after so maybe because it went way smoother because of the additive ? thats why i need to be sure guys before doing it. Thanks sorry for all this long story :mrgreen:

pdf copy of the TSB:
03-008-16.pdf | DocDroid
 
#3 ·
Here's an alternative...

I've checked with a number of custom roadster fabricators on this. These guys work with all brands of American muscle cars (Mopar, Ford, GM). The additive that is an absolute silencer on clutch-type LSD noise is this product (I use it in my SC truck with an Eaton/Yukon LSD). It's not Mopar (please don't shoot me!), but it sure as heck works with Royal Purple 75w140 gear oil. Of course, please use the Mopar friction modifier if that's where your comfort is.

 
#11 ·
It doesn't matter what additive to use am fine with any, but why adding more if the fluid already mixed with. what i'm trying to know which Mopar LSD Fluid part number that has additive mixed with so we can be clear, some people they don't care even if they will use a additional bottle but it doesn't make sense making the oil smother.
 
#4 ·
Ive used trans x friction modifier on a number of diff changes & have never had the rubbing/groan/grinding noise out of my LSDs. Half a bottle plus the almost 2 qts of gear oil, usually mobil 1
 
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#5 · (Edited)
After replacing a few clutch assemblies now with CF units, I now don't recommend / use friction modifiers because it is wearing out the clutch discs prematurely which leads to peg-legging.

During tight turning, without the modifier the clutch assembly grabs, releases and grabs repeatedly. In other words...the two clutch disc assemblies are doing their job properly by allowing for slippage as the right rear wheel (for example) in a tight left turn travels / rotates significantly further than the left wheel.

Adding a friction modifier compromises their ability to remain "locked" - once the discs begin to slip against each other. Although this is great for those who don't like (or think something is wrong that needs to be fixed) the resulting chatter, it also(!) compromises their ability for the discs to properly do their job in a straight line - by remaining locked to each other due to applied friction from the Bellevue washers.

In other words, during a burnout, or at any time traction is lost by one wheel, that friction modifier significantly compromises the clutch assembly's ability to re-lock. This action wears out the discs.

The use of the friction modifier to placate those who think something is wrong or don't "like" the noise / feeling. Like squeaky brakes...if you want the best performance from the LSD, avoid(!) the friction modifier.

Edit: there is no extra wear from not using the friction modifier.
 
#6 ·
After replacing a few clutch assemblies now with CF units, I now don't recommend / use friction modifiers because it is wearing out the clutch discs prematurely which leads to peg-legging.

During tight turning, without the modifier the clutch assembly grabs, releases and grabs repeatedly. In other words...the two clutch disc assemblies are doing their job properly by allowing for slippage as the right rear wheel (for example) in a tight left turn travels / rotates significantly further than the left wheel.

Adding a friction modifier compromises their ability to remain "locked" - once the discs begin to slip against each other. Although this is great for those who don't like (or think something is wrong that needs to be fixed) the resulting chatter, it also(!) compromises their ability for the discs to properly do their job in a straight line - by remaining locked to each other due to applied friction from the Bellevue washers.

In other words, during a burnout, or at any time traction is lost by one wheel, that friction modifier significantly compromises the clutch assembly's ability to re-lock. This action wears out the discs.

The use of the friction modifier to placate those who think something is wrong or don't "like" the noise / feeling. Like squeaky brakes...if you want the best performance from the LSD, avoid(!) the friction modifier.

Edit: there is no extra wear from not using the friction modifier.
Hey Simon! I can definitely see this happening if too much of the friction modifier is added. Thus far, my Eaton/Yukon LSD is working as expected for 1 year and counting... I'd add that not all friction modifiers are the same... Some just don't do a proper job...
 
#12 ·
I think I just fixed the problem after i read the TSB carefully drove the car in midnight and hit 179 mile and kept repeating it 4-5 times and then gone no noise I told my self it might be because the car/fluid are hot so drove it again in the morning and found nothing.

TSB NOTE: When releasing vehicle to the customer it is necessary to inform the customer that the vehicle will need to be driven approximately 160 to 240kilometers (100 to 150 miles) to allow fluid to penetrate clutches in rear differential.
 
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