Differential Fluid change

Kraty1

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I thought all Royal Purple already had fiction modifier in it?

You don’t want to double up on it because it allows too much clutch slippage. It helps longevity but renders the LSD less effective.
That was initially my thought, but my buddy who is also my service advisor, said to get the additive. I’ll have to research this further now...
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Lou Bunn

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Old guy of 60 here, and I did my daughter's Jeep at 20K miles. I used Royal Purple 75-90 and used a little under 3 quarts. There is a guy on YouTube that did a good video on this. I took his advice and bought the heavy duty thread tape for the plugs. Tip - wrap the tape counter clockwise on the threads. Take the top - fill plug off first (don't think there would be a problem but you don't want to drain and then can't refill). Easy job but like others said, that stuff STINKS!
 

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That was initially my thought, but my buddy who is also my service advisor, said to get the additive. I’ll have to research this further now...
I would add the Royal Purple (MaxGear has FM in the oil) and turn circles in a parking lot--both clockwise and counter-clockwise to see if you hear any chattering. I would only add more FM and only in small amounts until the chatter stops.
 

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I would add the Royal Purple (MaxGear has FM in the oil) and turn circles in a parking lot--both clockwise and counter-clockwise to see if you hear any chattering. I would only add more FM and only in small amounts until the chatter stops.
Does it stop excessive wife chatter?
 

nositting

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hey guys, i have a quick differential fluid question...
i have a 2019 sahara without the LSD so i’m guessing i’d be good with valvoline synthetic from corner auto store 75-110 up front and 75-140 in back without the extra fluid you need if you have the LSD, correct? i tow a couple times a year but nothing major. thanks for any help!
 

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hey guys, i have a quick differential fluid question...
i have a 2019 sahara without the LSD so i’m guessing i’d be good with valvoline synthetic from corner auto store 75-110 up front and 75-140 in back without the extra fluid you need if you have the LSD, correct? i tow a couple times a year but nothing major. thanks for any help!
I have done with same in my Rubicon with Amsoil (75W-110 in front and 75W-140 in the rear) and I would recommend the same viscosities for anyone with a JL due to the small capacity of the axle. Valvoline is good oil, though I have only seen Amsoil and RedLine in 75W-110. You will likely find 75W-90 and 75W-140 in Valvoline with no problems. If you have an Advance Auto in your area, you can usually find 20-25% off coupons online.

Hope this helps!
 

wheels082

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I have done with same in my Rubicon with Amsoil (75W-110 in front and 75W-140 in the rear) and I would recommend the same viscosities for anyone with a JL due to the small capacity of the axle. Valvoline is good oil, though I have only seen Amsoil and RedLine in 75W-110. You will likely find 75W-90 and 75W-140 in Valvoline with no problems. If you have an Advance Auto in your area, you can usually find 20-25% off coupons online.

Hope this helps!
I also used Amsoil in my differentials when I changed the diff fluid in my JLU. When I had a Truetrac installed in my JKU I asked Eaton if they had any oil recommendations. They told me I could use anything I wanted except Valvoline or NAPA.
 

nositting

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I also used Amsoil in my differentials when I changed the diff fluid in my JLU. When I had a Truetrac installed in my JKU I asked Eaton if they had any oil recommendations. They told me I could use anything I wanted except Valvoline or NAPA.
[/QUOTE]

why no valvoline? i thought they made good products?
 

1977Jimmy

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Napa oil is rebranded valvoline. Nothing wrong with either.
 

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Instruction manual reads 75W85, and specifies to add a FM if you have Trac-Lok LSD (I believe that's a brand name for the Dana 44). Of course they recommend the Mopar lube :LOL:

I've noticed people here going with heavier weights. Is there any sort of consensus around the best weight, or does it depend on application? My application is local driving with a combination of paved and unpaved roads and muddy trails, beach driving, and some highway driving (not regularly). No crawling envisioned.

Also, do we know which lubes have the friction modified included in sufficient quantities to meet the requirements of the LDS?

I'm getting ready to do this and just want to order the correct lube. Thanks!
 

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https://www.jlwranglerforums.com/forum/threads/differential-fluid.14689/post-664673

This thread should help with some of the confusion with different viscosities floating around.

I haven’t gotten around to it yet but i have ordered Amsoil 75-90 for the front and 75-140 for the rear (M220 with LSD and tow). I also ordered the mopar friction modified and I believe plan on adding 2.6 Oz of friction modified per Amsoil’s vehicle selector page.
 

wheels082

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Instruction manual reads 75W85, and specifies to add a FM if you have Trac-Lok LSD (I believe that's a brand name for the Dana 44). Of course they recommend the Mopar lube :LOL:

I've noticed people here going with heavier weights. Is there any sort of consensus around the best weight, or does it depend on application? My application is local driving with a combination of paved and unpaved roads and muddy trails, beach driving, and some highway driving (not regularly). No crawling envisioned.

Also, do we know which lubes have the friction modified included in sufficient quantities to meet the requirements of the LDS?

I'm getting ready to do this and just want to order the correct lube. Thanks!
A lot of the gear lubes contain friction modifiers for a LSD. I used the Amsoil Severe Gear and it has been working great. For trailer towing or more severe applications heavier viscosity's are typically recommended. There are no negatives to using a heavier viscosity except in very cold climates other than a slight penalty in fuel economy. I used the 75w90 in mine front and rear.
https://www.amsoil.com/p/severe-gear-75w-90-svg/?zo=226468
 

Rufus

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A lot of the gear lubes contain friction modifiers for a LSD. I used the Amsoil Severe Gear and it has been working great. For trailer towing or more severe applications heavier viscosity's are typically recommended. There are no negatives to using a heavier viscosity except in very cold climates other than a slight penalty in fuel economy. I used the 75w90 in mine front and rear.
https://www.amsoil.com/p/severe-gear-75w-90-svg/?zo=226468
Thank you. Based on the below from their website do I NOT need to add an additional FM?
“This state-of-the-art AMSOIL formulation features an exclusive blend of high-viscosity, shear-stable synthetic base oils and an extra treatment of high-performance additives.”
 

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Thank you. Based on the below from their website do I NOT need to add an additional FM?
“This state-of-the-art AMSOIL formulation features an exclusive blend of high-viscosity, shear-stable synthetic base oils and an extra treatment of high-performance additives.”
I have recommended to several here that if the gear oil states that it already has FM in it, to have extra FM on hand, but do not add it at first. Get into an open parking lot and make several 360° circles (both clockwise and counter-clockwise) and listen for any chattering. If you do not hear any, then you are good to go. If you do, add only small amounts of FM (perhaps 1/2 ounce at a time) until the chattering stops. You can add too much FM in an LSD axle to the point where the clutches continuously slip and then you basically have an "open axle".
 
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