Rear Locking Differential

[Dusty1948]

Thanks Dusty. Many owners never change the diff fluid. Very ignored item.

Thanks. Now that I re-read your earlier post, I should add that I have always used the 75-140 Mopar gear oil, which is rated as "heavy duty." Going back to previous Ram 1500s and my one Dakota (all with 9.25 ring gears) , I was towing a lot more back then, both in terms of weight and frequency. The factory fill has always been 90W gear oil, which is probably sufficient for daily driving and very light loads. They use 90W to reduce parasitic load losses and improve gas mileage. But I agree if you're going to be towing or carry load anywhere near the vehicle limit, I'd use the heavy gear oil. In fact, I guess I'd use it all the time.

Note that on the optional 9.75 ZF version they actually circulate engine coolant back to the diff.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 17 July 2018. Now at: 031474 miles.

 

[c3k]

Note that on the optional 9.75 ZF version they actually circulate engine coolant back to the diff.

Forgive the necro thread. The above statement reminded me of something I read about this system. It seems it is meant to HEAT the rear differential. That reduces friction and gives a CAFE bonus to Ram. I =thought= it has a valve that shuts it off at certain temperature, but that could very well be me mis-remembering what I read. If the loop is open all the time, then at heavy loads it will, indeed, work to cool the differential.

It sticks in my mind because it was not a cooling system (that I thought would be a very useful addition to a heavy duty truck).

 

[Dusty1948]

Forgive the necro thread. The above statement reminded me of something I read about this system. It seems it is meant to HEAT the rear differential. That reduces friction and gives a CAFE bonus to Ram. I =thought= it has a valve that shuts it off at certain temperature, but that could very well be me mis-remembering what I read. If the loop is open all the time, then at heavy loads it will, indeed, work to cool the differential.

It sticks in my mind because it was not a cooling system (that I thought would be a very useful addition to a heavy duty truck).

Hello c3k, my apologies.

In an effort to be brief my response was obviously lacking in description. You are correct, the coolant is circulated to both warm and cool the differential for different seasonal ambient temperatures. This is Ram's approach to increasing efficiency, in the same manner that they pre-heat transmission fluid.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037904 miles.

 

[Bobby Boca]

I recently bought a 2021 Ram 2500 midnight edition with a Cummins the truck basically had every I wanted but anti slip differential was not included . With that said I thought I could add it in the future but now speaking to a few Dodge service places I’m told it can’t not be done because it’s not a simple add on and that the comp need to be worked on also and they will not touch this work I wanted to be done . So my question is can this be done after market ?

 

[Mountain Whiskey]

I recently bought a 2021 Ram 2500 midnight edition with a Cummins the truck basically had every I wanted but anti slip differential was not included . With that said I thought I could add it in the future but now speaking to a few Dodge service places I’m told it can’t not be done because it’s not a simple add on and that the comp need to be worked on also and they will not touch this work I wanted to be done . So my question is can this be done after market ?

Certainly! The aftermarket has a wide range of limited slip, electronic lockers, pneumatic lockers, cable controlled lockers a plethora. Find a reputable 4x4 shop. Don't let the stealership do it, there is a reason they refuse. Their ammatures will screw it up. Jeep owners change gears and lockers like they change underwear.

Is it a cheap bolt on? Nope. I had the rear in my town car changed not long ago. I bought the parts and it was $600 labor. Your truck has two differentials. Most make you buy parts through them and mark them up.

They say the computer needs work because the system needs to know what gears you have for shifting and speed. A Tazer will allow this to be set though. I guess if you don't change gear ratios it should not matter though.

 

[Bobby Boca]

Ok thank you for getting back to to my post I have 2 questions
1- You mentioned a Tazer what is that ?
2-Do you know any website I can find The parts I will need ?

 

[Mountain Whiskey]

It's a module that plugs in above the OBD plug under your dash and allows for non performance adjustments to the trucks system. It is a Tazer DT by Z Automotive. I don't know why one would be needed if you are not changing gear ratios though. It does a lot of other tricks.

For a limited slip or a locker, if you don't know where to buy, the shop doing the install should purchase what is needed. It is not a simple bolt on.

For all the above, Google is your friend. Rear end parts are countless. You can get parts and kits from Rock Auto to American Trucks to Summit Racing.

 

[Bobby Boca]

Thank you ..

 

[PCT]

I was reading on the other ramform, and it seems that the 1500 use clutch packs and HD use a helical design. Cant seem to confirm that, but that would be amazing if the HD us helical