What's everyone using in their differentials?

[kdoublep]

It's that time. Im pushing 60K. What's everyone using? I have 3.92 w/ anti spin which requires additive. I got the Mopar Friction modifier.

I don't do heavy off roading but still want to be prepared to do so. I haul a decent payload often. Don't tow but may. Truck is quiet and want to keep it that way.

 

[HSKR R/T]

I voted based on what I prefer in my other vehicles, but still running the factory fill in my Ram.

 

[Scram1500]

Amsoil 75W-140 Severe Gear and Mopar additive (04318060AD).

Pretty sure Amsoil used to be more straight forward about this, but now they state Severe Gear already contains modifiers. I think they used to say add friction modifier for clutch style LSD.

This is from the current data sheet:

AMSOIL SEVERE GEAR is compatible with most limited-slip differentials. For applications that require additional limited-slip friction modifier, add AMSOIL Slip Lock.®

Edit: Here is the specific vehicle application on Amsoil's site for Ram 1500 3.92 rear with LSD

Notes:	(1) Add 5 oz (148 ml) of Mopar limited-slip additive (MS-10111)

 

[JF19Longhorn]

Went with Amsoil in all three (whatever weight/type they recommended for each).

 

[cskindt]

Red Line Synthetic Oil. Gear Oil for Differentials

Gear Oil for Differentials

www.redlineoil.com

The standard gear oil already has friction modifiers in it. No additional is necessary.

 

[HSKR R/T]

Red Line Synthetic Oil. Gear Oil for Differentials

Gear Oil for Differentials

www.redlineoil.com

The standard gear oil already has friction modifiers in it. No additional is necessary.

Not always true. Sometimes the amount pre-mixed isn't enough. They are still using the same basic corporate 9.25 rear differential that has been in use for decades. Sure there have been updates, but same basic design. And I know for fact, due to previous and current trucks I own that there isn't a single differential fluid, listed as already having friction modifier in it, that has the correct amount for the limited slip 9.25s used in the Dakota/Durango/Rams in late 90s early 2000s.

 

[cskindt]

Not always true. Sometimes the amount pre-mixed isn't enough. They are still using the same basic corporate 9.25 rear differential that has been in use for decades. Sure there have been updates, but same basic design. And I know for fact, due to previous and current trucks I own that there isn't a single differential fluid, listed as already having friction modifier in it, that has the correct amount for the limited slip 9.25s used in the Dakota/Durango/Rams in late 90s early 2000s.

I didn't have to add any additional modifier.

Here are RL's comments from their white paper:

LIMITED-SLIP COMPATIBILITY
Red Line Gear Oils, with the exception of the
75W90NS, and 75W140NS, already contain friction
modifier required for operation in limited-slip differen-
tials. Additional additive is not usually required, but
newer units or those with more lockup capability may
require 1-4% additional Red Line Limited-Slip Friction
Modifier. If Red Line is not available, the manufacturers
recommended friciton modifier is compatible. Do not
add addtional modifier unless necessary, as too much
will result in excessive wheel spin. To perfectly tune a
differential, start with the 75W90 NS or 75W140 NS and
add the Red Line Limited-Slip Friciton Modifier until the
limited-slip chattering just disappears.

From their product data sheet:

Contains additional friction modifiers for suitability with clutch-type limited-slip differentials - for
most LSDs, no additional friction modifiers are required

 

[HSKR R/T]

I didn't have to add any additional modifier.

Here are RL's comments from their white paper:

LIMITED-SLIP COMPATIBILITY
Red Line Gear Oils, with the exception of the
75W90NS, and 75W140NS, already contain friction
modifier required for operation in limited-slip differen-
tials. Additional additive is not usually required, but
newer units or those with more lockup capability may
require 1-4% additional Red Line Limited-Slip Friction
Modifier. If Red Line is not available, the manufacturers
recommended friciton modifier is compatible. Do not
add addtional modifier unless necessary, as too much
will result in excessive wheel spin. To perfectly tune a
differential, start with the 75W90 NS or 75W140 NS and
add the Red Line Limited-Slip Friciton Modifier until the
limited-slip chattering just disappears.

From their product data sheet:

Contains additional friction modifiers for suitability with clutch-type limited-slip differentials - for
most LSDs, no additional friction modifiers are required

Which says exactly what I said. There isn't enough for all limited slips, and some will require more. And I cited a specific example of one that does require more based on personal experience and experience of many others with the same vehicles

 

[cskindt]

Which says exactly what I said. There isn't enough for all limited slips, and some will require more. And I cited a specific example of one that does require more based on personal experience and experience of many others with the same vehicles

It's just a PSA that is pertinent to any gear lube/modifier blend.
In my experience, I didn't require additional.
Some may, regardless of brand.

Just as you said ....

 

[kdoublep]

BTW this is my first truck. My guess is I'll be adding modifier. I'll get to it soon and post my experience.

I'm looking at Amsoil. Price is good on their site and I get free shipping and an awesome free tool that may save my life some day.

2 qts front
3 qts rear

What about transfer case? What am I using there?

And thanks for the comments. Much appreciated!

 

[1BADRAMLIMITED]

My trucks at 88k and wanting to tackle this job myself.

I believe a while back I input my vin and it showed me everything my truck was equipped with and seen 3.92 gears how do I confirm this? FCA RAM

I have a 19 limited ORP with 4x4 of course and the axle locker, down hill assist . I just want to make sure I’m buying the right stuff. Thanks in advance

given this video even if u have 3.92 gears u may not need friction additive? Only if u have a limited slip??

 

[kdoublep]

My trucks at 88k and wanting to tackle this job myself.

I believe a while back I input my vin and it showed me everything my truck was equipped with and seen 3.92 gears how do I confirm this? (I don’t remember the website I put my vin in at it was some FCA webpage I found on the forum)

Saw this. Thank you.

 

[cskindt]

BTW this is my first truck. My guess is I'll be adding modifier. I'll get to it soon and post my experience.

I'm looking at Amsoil. Price is good on their site and I get free shipping and an awesome free tool that may save my life some day.

2 qts front
3 qts rear

What about transfer case? What am I using there?

And thanks for the comments. Much appreciated!

View attachment 164282

I used this in the transfer case:

MT-LV 70W/75W GL-4 Gear Oil

Meet our newest addition to the GL-4 family!

www.redlineoil.com

 

[kdoublep]

Must have a lot of low mileage trucks out there or nobody likes polls

 

[Mountain Whiskey]

I voted based on what I prefer in my other vehicles, but still running the factory fill in my Ram.

I did the same. 38k is too soon to change since I haven't done any deep water crossings or anything.

Not always true. Sometimes the amount pre-mixed isn't enough. They are still using the same basic corporate 9.25 rear differential that has been in use for decades. Sure there have been updates, but same basic design. And I know for fact, due to previous and current trucks I own that there isn't a single differential fluid, listed as already having friction modifier in it, that has the correct amount for the limited slip 9.25s used in the Dakota/Durango/Rams in late 90s early 2000s.

Agree here. Don't know about the Ram but I have owned plenty of LS rears and no matter what the bottle says I tend to get chatter so I add a little of the stinky stuff!

My trucks at 88k and wanting to tackle this job myself.

I believe a while back I input my vin and it showed me everything my truck was equipped with and seen 3.92 gears how do I confirm this? (I don’t remember the website I put my vin in at it was some FCA webpage I found on the forum)

I have a 19 limited ORP with 4x4 of course and the axle locker, down hill assist . I just want to make sure I’m buying the right stuff. Thanks in advance

To know your gear ratio, do they still put the little metal tag on one of the cover bolts or am I just showing my age?

You can always just count too. What I mean is jack up the rear (one tire for open dif, both for LS) put a mark on your driveshaft and one on your tire. Turn the tire one full rotation while watching the shaft. If it turns 3.92 times, you have a real truck. If it turns 3.21 times, just give it to your 10 yr old daughter.