Differential Oil Additive - Rear D44 LSD

[NovaJeep]

Hey All,

Just looking for a second opinion on this one. I was recently offroad and had my axles in some water, possibly as high as the breather on the rear. To be sure, I purchased some diff oil and additive for the LSD rear. The Mopar LSD additive instructions calls for 2-5% by gear oil weight. I'm using 75W-140 Mopar synthetic in the rear.

Dealer indicated I should use the full 120ml vial of additive in the rear, then fill the diff to the fill line with 75W-140. Does that sound right? I'm not sure how the calculation works for 2-5% by gear oil weight

MOPAR Part 4318060AB

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[Sheepjeep]

Diff takes about 2 quarts (64 oz) and additive bottles is 4 oz., so dumping the whole bottle will be about 6.25% by weight which overall is not bad and there is always a little bit that gets left behind in the bottle. So dump the whole thing.

 

[NovaJeep]

Diff takes about 2 quarts (64 oz) and additive bottles is 4 oz., so dumping the whole bottle will be about 6.25% by weight which overall is not bad and there is always a little bit that gets left behind in the bottle. So dump the whole thing.

Thank you! Always like to have a second opinion.

 

[JIMBOX]

If your using any top synthetic--VALVOLINE/MOBILE ONE-ETC

They all have LSD addition already--read the bottle !

W.E.

JIMBO

 

[BrntWS6]

Amsoil still recommends the mopar limited slip additive even with their synthetic gear oil.

 

[basinite]

I changed my rear differential oil today. Jeep only has 4,900 miles, but I wanted to get the factory oil out and see if I had any unusual wear. As expected, the oil was as black as tar. Not sure what it is with LSD rear ends, but I've always noticed the oil looks like garbage after initial break-in. After the initial oil change, the oil doesn't get so black.

I did not use any friction modifier, since its already in the purple oil. I took the Jeep for a spin and peeled the tires. I didnt hear any unusual noises and the tires locked up fine.

The rear end took just shy of 2 quarts. I changed in my garage (level surface) and did not lift the Jeep. Just the usual amount of metal gunk on the drain plug and everything looked fine.

It took me longer to change the oil in my lawn mower. I cant believe the dealerships are charging people $300 to change out differential oil. Crazy!!!

 

[Kraty1]

I changed my rear differential oil today. Jeep only has 4,900 miles, but I wanted to get the factory oil out and see if I had any unusual wear. As expected, the oil was as black as tar. Not sure what it is with LSD rear ends, but I've always noticed the oil looks like garbage after initial break-in. After the initial oil change, the oil doesn't get so black.

I did not use any friction modifier, since its already in the purple oil. I took the Jeep for a spin and peeled the tires. I didnt hear any unusual noises and the tires locked up fine.

The rear end took just shy of 2 quarts. I changed in my garage (level surface) and did not lift the Jeep. Just the usual amount of metal gunk on the drain plug and everything looked fine.

It took me longer to change the oil in my lawn mower. I cant believe the dealerships are charging people $300 to change out differential oil. Crazy!!!

Im doing this myself here soon, thanks!

 

[MatthewAMEL]

I have a JLURD.

Doing diff service soon. Does the front diff need the Friction Modifier also?

I am using the Red Line 57104 which DOES NOT have the modifier added already.

Thanks!

 

[word302]

I have a JLURD.

Doing diff service soon. Does the front diff need the Friction Modifier also?

I am using the Red Line 57104 which DOES NOT have the modifier added already.

Thanks!

If you have a rubicon you don’t have a LSD, no need for friction modifier.

 

[David E]

I have a JLURD.

Doing diff service soon. Does the front diff need the Friction Modifier also?

I am using the Red Line 57104 which DOES NOT have the modifier added already.

Thanks!

I have 2021 JLURD also, your rear needs friction modifier the front does not. Rear is M220 and will take 1.53 quarts, front should be M210 and take 1.09 quarts.
I used Valvoline 75-140 (only recommend if towing) since I tow a little. Book list 75w85 in rear if not towing. I added 2 Oz of modifier even though Valoline claimed didn't need (mopar still recommend). Front I used valvoline 75w90 book recommend 75w85. Valvoline doesn't make 75w85.

 

[David E]

If you have a rubicon you don’t have a LSD, no need for friction modifier.

He has the Diesel which is M220 rear with 3.73 gears. It needs the Friction Modifier. Only option if you get the diesel is 3.73 gears even if it's a Rubicon.

 

[word302]

He has the Diesel which is M220 rear with 3.73 gears. It needs the Friction Modifier. Only option if you get the diesel is 3.73 gears even if it's a Rubicon.

That is incorrect. The gears have nothing to do with needing friction modifier. He has a Rubicon. It comes with lockers, not a LSD. Lockers do not require friction modifier.

 

[word302]

I have 2021 JLURD also, your rear needs friction modifier the front does not. Rear is M220 and will take 1.53 quarts, front should be M210 and take 1.09 quarts.
I used Valvoline 75-140 (only recommend if towing) since I tow a little. Book list 75w85 in rear if not towing. I added 2 Oz of modifier even though Valoline claimed didn't need (mopar still recommend). Front I used valvoline 75w90 book recommend 75w85. Valvoline doesn't make 75w85.

You seem to have a gross misunderstanding of what friction modifier is for.

 

[MatthewAMEL]

Not to add fuel to the fire...after the confusion here, I asked the Dealer and a local 4WD shop...both said no friction modifier for the diffs with lockers. Only with LSD.

Dealer said if your fluid comes with additive, you can use it but not required. Modifier is only required if the diff has clutch plates (LSD).

To sum up:

Tru-lok - no modifier (Rubicon)
Trac-lock - modifier

 

[CarbonSteel]

Not to add fuel to the fire...after the confusion here, I asked the Dealer and a local 4WD shop...both said no friction modifier for the diffs with lockers. Only with LSD.

Dealer said if your fluid comes with additive, you can use it but not required. Modifier is only required if the diff has clutch plates (LSD).

To sum up:

Tru-lok - no modifier (Rubicon)
Trac-lock - modifier

Most synthetic gear oils come with friction modifier in them and it is usually enough to prevent chattering. I have not seen an LSD chatter in years with synthetic oil, but can with conventional.

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