diff fluid change on a 3.21

[ramffml]

Please guys. I'm getting ready to sleep in 10 minutes and I don't need the nightmare material.

 

[ramffml]

Just to update the thread: I changed my fluid, it looked in great shape yet, nothing resembling wear that I could see in there. Truck is at 93,000 km or about 58,000 miles, lots of towing over the 4 years. It started making a groaning noise during my last tow trip of the season, I'd be at a stop (even unloaded without any weight in truck), turn left or right and it would then groan through the corner and then once I was straight the noise would go away.

So I put in Amsoil severe gear 75w-110. I compromised, its higher than factory oil but I'm a little skittish on the thicker viscosities. Also added the 1 tube of Amsoil slip lock which is meant for limited slip diffs like mine is. I'm hoping I did the right thing there with that additive? I could have added the mopar stuff but that means talking to the dealer guys which is a problem since we don't get along all that well anymore (there might have been a wee incident a while back)

Went for a boot and haven't heard the noise once.

https://www.amsoil.ca/p/slip-lock-adatb/?code=ADATBC-EA

 

[danielmid]

I think the Severe Gear has the LS added in already, but as long as you don't have any noise or weird slippage issues it shouldn't hurt. Good oil choice.

 

[ramffml]

I think the Severe Gear has the LS added in already, but as long as you don't have any noise or weird slippage issues it shouldn't hurt. Good oil choice.

Yes this was a source of confusion for me. I'm not sure where I read this, but somewhere somebody said the oil is still needed for clutch based diffs like ours.

 

[DanAR]

I’ve found that even the differential lubes advertising LS friction modifiers in them will often still have limited slip chatter unless a bottle of the additive is also added. So no harm.

 

[quickster2]

My experience is that if it calls for the modifier then you need it regardless of what the bottle states (LS included yes or no). Don't add more than it recommends.

 

[Zeak]

So I ordered gear oil for my truck but wound up ordering the 75W85 with friction modifier that I intended to use in the front differential. Would it be an issue to go ahead and use this or should I return and get the 75W90 NS fluid. It would save me about $10 if I exchanged.

 

[Dodge 1500 4X4]

added the 1 tube of Amsoil slip lock which is meant for limited slip diffs like mine is. I'm hoping I did the right thing there with that additive?

I also have the 3.21 W/ Anti Spin Differential Rear axle, is this also called a Limited slip diff?

 

[ramffml]

I also have the 3.21 W/ Anti Spin Differential Rear axle, is this also called a Limited slip diff?

Yes, anti spin = limited slip.

There are 3 options for our trucks: open diff (nothing to lock), anti-spin/limited slip, and electronic locking diff.

 

[Wild one]

So I ordered gear oil for my truck but wound up ordering the 75W85 with friction modifier that I intended to use in the front differential. Would it be an issue to go ahead and use this or should I return and get the 75W90 NS fluid. It would save me about $10 if I exchanged.

Your truck if it's a 14 calls for 75W-140,and being in Texas that's what i'd run

 

[Zeak]

Your truck if it's a 14 calls for 75W-140,and being in Texas that's what i'd run

This is would be for the front. I already put the 140 in the rear. I’m interested in opinions of putting the fluid with friction modifiers in the front with no limited slip.

 

[Zeak]

It looks like on the Redline website when entering my truck info it shows the 75W85 for hypoid limited slip differentials for my front axle. So I suppose I’ll go ahead and use what I have.

 

[quickster2]

So I ordered gear oil for my truck but wound up ordering the 75W85 with friction modifier that I intended to use in the front differential. Would it be an issue to go ahead and use this or should I return and get the 75W90 NS fluid. It would save me about $10 if I exchanged.

Limited Slip rated gear oil will not hurt an open (non LS) differential if that is your question.

 

[quickster2]

It looks like on the Redline website when entering my truck info it shows the 75W85 for hypoid limited slip differentials for my front axle. So I suppose I’ll go ahead and use what I have.

LS rated gear oil will not hurt a differential that does not call for it.