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Do I have a limited slip differential?

TJim

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Hey!

My VIN Equipment Listing mentions that I have Command-Trac Part Time 4WD System.

Does that mean that I have a Limited Slip differential, right?

I am about to change my diff fluids, and the manual says that: Models equipped with Trac-Lok require an additive.

I have 2x Mopar Limited Slip Additive (4 oz each).

The Limited Slip Differential is only the rear (Dana 35) or the front (Dana 30) too? Should I add the additive only in the rear diff or in both?

Sorry for the "noob" question, I'm just trying to figure everything out.
 
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TJim

TJim

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I forgot to add that I have a TJ 2004 with


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Engine
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2.4L PowerTech I4 16V​
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Transmission
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NV1500 (5-Speed Manual)​
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Transfer Case
[/TD]
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NV231 Transfer Case​
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Front Differential
[/TD]
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Dana 30 Axle​
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Rear Differential
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Dana 35 Axle​
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Axle Ratio
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4.11​
[/TD]
 

Steel City 06

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Generally, factory limited slip differentials are limited to the rear axle only. The front is almost always open.
The exception is certain trim packages on certain vehicles may have a front locker, but this will be clearly advertised as such (for a Jeep you would have to have a Rubicon model).
 
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pagrey

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And to beat the dead horse, even a Rubicon doesn't get the additive in the front diff.

To be clear, if your build sheet doesn't say trac-lok you don't need additive anywhere. If it does you need it in the rear only.
 
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RubiconMike

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If I remember correctly, the Rubicon limited-slip is a gear type (like a Detroit Tru-Trac) while the non-Rubicon models got a clutch-pack limited-slip (like a GM Positraction). I think it was only the clutch-pack type that needed special lube.

To the original poster, if you don't have documentation on what's in your axle, here's a way to test. Put everything in neutral and jack up the rear so both wheels are off the ground. Turn one of the wheels by hand, if you have limited slip, the other wheel will turn in the same direction, if you don't, it will turn in the opposite direction.

I believe this is correct, but if not, I'm sure someone will reply with better information.
 
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RubiconMike

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I was able to find this: The Rubicon TJ had a Tru-Lok in the rear, it's a gear type limited slip combined with a manually selectable locker and does not need special lube. The non-Rubicon models had an optional Trac-Lok that is a clutch type limited slip and does need special lube.

Trak-Lok
trac-lok.jpg


Tru-Lok
jjftjeeprub01.jpg
 
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OP
TJim

TJim

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Thanks Guys for the answer.

So it seems no Limited Slip Diff for me. I have already purchased Mopar Gear- and Axle Lubricant 80W-90 MS-9020.

I have 3 Quarts.

Do you know if that will be enough by personal experience or I must buy 1 more Quart?
I have Dana 30 front and Dana 35 rear.
I have searched a lot about the Fluid Capacities but I have come across into slightly different answers.

Are 3 Quarts of 80W-90 Axle Lubricant enough for both diff fluid change?


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freedom_in_4low

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if you get a gear oil labeled that it's for limited slip differentials, you don't even need the additive and this all becomes a moot discussion.

Either way, you'll know when you pull the cover off because the carrier that contains the spider gears on an open differential is bell-shaped,

20200224_194816.jpg




while the limited slip carrier is more cylindrical.

20170701_093247.jpg
 
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Modoc Guy

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Thanks to the OP for the question. The PO of my 02 TJ put a Dana 44 under my Jeep, and I was wondering how I could tell what I had in it once I pulled the diff cover. Now that I've seen the pix of seemingly every variety of rear end, I'll be able to answer that question. 😺
 
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TJim

TJim

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Thanks everyone! I will do the test of spinning the rear wheels as soon as I can.

Do you know the exact Fluid Capacity for the Dana 30 and the Dana 35? (For 80w-90)
 

Noslo65

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Feb 24, 2019
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Central Illinois
Hey!

My VIN Equipment Listing mentions that I have Command-Trac Part Time 4WD System.

Does that mean that I have a Limited Slip differential, right?

I am about to change my diff fluids, and the manual says that: Models equipped with Trac-Lok require an additive.

I have 2x Mopar Limited Slip Additive (4 oz each).

The Limited Slip Differential is only the rear (Dana 35) or the front (Dana 30) too? Should I add the additive only in the rear diff or in both?

Sorry for the "noob" question, I'm just trying to figure everything out.
Command-Trac part time 4 wheel drive is what the 4 wheel drive system in the TJ is called and has nothing to do with the differentials.
 
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freedom_in_4low

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Do you know the exact Fluid Capacity for the Dana 30 and the Dana 35? (For 80w-90)

181 FBI refers to the Dana 30, 194 RBI refers to the Dana 35.

Converting the liters to quarts, it looks like 3.001 quarts. I wouldn't have guessed that was enough, but that's the numbers.

1586893265514.png
 

89grand

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The best way to know for sure is to pull the rear diff cover. An open diff looks different from the factory trac-loc like shown above.

Yes, the Dana 35 can get the trac-loc from the factory. Mine came that way. I replaced it with a Detroit TT when I had it regeared.