JT Diesel Selec-trac

[DC3]

As everyone already knows, the selec-trac is not available in the diesel. I purchased an MP3022 selec-trac transfer case (the transfer case for non-Rubicons) for a swap I intended to do on my supercharged JT but I never got to do the swap and I am selling the truck.

I have done a ton of research on the necessary components and already have the wiring harness, shift lever assembly, and transfer case control module. I have not found information on the true torque capacity of the transfer case or the confirmed reasoning for selec-trac not offered as a factory option on the diesel. Of course, there is a lot of speculation and anecdotal opinions about torque capacity.

I am posting this here to see if anyone has the real scoop about why Selec-trac is not available on the diesel.

I am not fearful of the swap itself, I believe I am the first to figure out the paddle shifter swap and adaptive cruise control. I have the Mopar programming pod and tech subscription so I have the tools necessary to do the swap... But I am missing the factory limitation for not offering selec-trac with diesel.

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[Darkspeed]

This an option i wanted for my diesel. Subscribed..

 

[Sandevino]

The selec-trac AWD system allows the wheels to slip and directs traction to the wheels that need it based on conditions. To allow the AWD system to function properly, a clutch pack is used in the transfer case making it great on road but off-road it generates heat and is prone to overheating. The gas engines don’t make enough torque down low (under 2500 rpm) when operating slowly in AWD to heat the clutches up enough when slipping. The diesel on the other hand makes maximum torque around 2000 rpm and will rip the clutches free and heat them up when they start to slip.

Looking at the schematics for the MP3022 (Selec-Trac II) transfer case, there is no chain and sprocket assembly as found in the command-trac and rock-trak systems.

The same issue has been reported (overheating) with the 2020 and newer Ram 1500 EcoDiesel models equipped with the BW 48-11 when pulling in four wheel low.

This video show the enjoyment of heating up the transfer case clutches.

Ram 1500 BW 48-11 transfer case overheating

 

[DC3]

The selec-trac AWD system allows the wheels to slip and directs traction to the wheels that need it based on conditions. To allow the AWD system to function properly, a clutch pack is used in the transfer case making it great on road but off-road it generates heat and is prone to overheating. The gas engines don’t make enough torque down low (under 2500 rpm) when operating slowly in AWD to heat the clutches up enough when slipping. The diesel on the other hand makes maximum torque around 2000 rpm and will rip the clutches free and heat them up when they start to slip.

The same issue has been reported (overheating) with the 2020 and newer Ram 1500 EcoDiesel models equipped with the BW 48-11 when pulling in four wheel low.

This video show the enjoyment of heating up the transfer case clutches.

Ram 1500 BW 48-11 transfer case overheating

WOW this is really helpful. I embarrassingly didn't consider the fact that the clutches are used in all 4wheel drive modes.

Now my OCD will drive me to dig deep into the 392 Transfer case specs

 

[Sandevino]

WOW this is really helpful. I embarrassingly didn't consider the fact that the clutches are used in all 4wheel drive modes.

Now my OCD will drive me to dig deep into the 392 Transfer case specs

Don’t do it. A buddy of mine is a master mechanic at a local Jeep dealership and one of the top warranty claims (mostly denied) are fried transfer case clutches.

 

[DC3]

Don’t do it. A buddy of mine is a master mechanic at a local Jeep dealership and one of the top warranty claims (mostly denied) are fried transfer case clutches.

Thanks for the advice, I now have an extra 4 hours to do meaningful work today! Thanks for saving half my day, a quarter of my weekend

Case closed, for me.

 

[Sandevino]

While we’re on the topic, the EcoDiesel requires the beefier 8HP75 transfer case to handle the torque it puts out. The 392 also requires the 8HP75 not for torque but the bolt pattern of the block will not mount up to the 850RE.

The 392 is a decent engine but only when you wind it out to 4000+ rpm does it start to make the same torque (albeit less 420 vs 440 and 480 in the Ram 1500) as the EcoDiesel at half the speed.

If you build a 392 Wrangler, nowhere does it give you an option to select the highly coveted rock-trak you get with the Rubicon. Those buying it ASSUME you get the rock-trak only to find out they get the same clutch driven transfer case from the Jeep Liberty. Let that sink in….

Here‘s an interesting read on how the 392 came to be - How the 392 came to be

 

[KW80]

It seems the Euro Spec Gladiator offers a package with both EcoD and Selec-trac. My guess is FCA/Stellantis just didn’t want to pay for certification of another diesel variant here in the US. Once my powertrain warranty is up I will likely do the switch to front cv joints but changing out everything else associated with Selec-trac offers more risk than reward for me.

https://www.jeepgladiatorforum.com/...ell-is-up-with-the-euro-spec-gladiator.60762/

 

[PlayfulBird]

The selec-trac AWD system allows the wheels to slip and directs traction to the wheels that need it based on conditions. To allow the AWD system to function properly, a clutch pack is used in the transfer case making it great on road but off-road it generates heat and is prone to overheating. The gas engines don’t make enough torque down low (under 2500 rpm) when operating slowly in AWD to heat the clutches up enough when slipping. The diesel on the other hand makes maximum torque around 2000 rpm and will rip the clutches free and heat them up when they start to slip.

Looking at the schematics for the MP3022 (Selec-Trac II) transfer case, there is no chain and sprocket assembly as found in the command-trac and rock-trak systems.

The same issue has been reported (overheating) with the 2020 and newer Ram 1500 EcoDiesel models equipped with the BW 48-11 when pulling in four wheel low.

This video show the enjoyment of heating up the transfer case clutches.

Ram 1500 BW 48-11 transfer case overheating

I know the JT (Diesel is the only option) sold here(Germany) all have the selec trac. So I don't see that there is a mechanical reason why it is not available/convertible in the states.

Just saw @KW80 said this also

 

[Sandevino]

I know the JT (Diesel is the only option) sold here(Germany) all have the selec trac. So I don't see that there is a mechanical reason why it is not available/convertible in the states.

Just saw @KW80 said this also

There has to be something market or use case specific.

 

[PlayfulBird]

There has to be something market or use case specific.

Well to tell you honestly, I don't think the Germans could handle not having the 4wd Auto on their shifter. ? I am joking mostly, we have some very good drivers(but also extremely many on the not so good spectrum), but looking at the market, there is a need here to have a 4wd option that is capable of dealing with on road use and does not require thinking. The 4x4 with traditional rear wheel drive with a 4 high/low do not sell as well IMO.
A little rain or a little snow, and half the country forgets how to drive.

 

[Sandevino]

Well to tell you honestly, I don't think the Germans could handle not having the 4wd Auto on their shifter. ? I am joking mostly, we have some very good drivers(but also extremely many on the not so good spectrum), but looking at the market, there is a need here to have a 4wd option that is capable of dealing with on road use and does not require thinking. The 4x4 with traditional rear wheel drive with a 4 high/low do not sell as well IMO.
A little rain or a little snow, and half the country forgets how to drive.

Same goes for half of Texas when it rains. It could very well be a use case issue.

 

[Pescatoral Pursuit]

Sounds like Jeep is at least willing to vouch for the warranty period. My question is the German 3.0 the same power specs?

 

[PlayfulBird]

Sounds like Jeep is at least willing to vouch for the warranty period. My question is the German 3.0 the same power specs?

Yes it is.
We did discuss this in another thread as we already had suspicions.
https://www.jeepgladiatorforum.com/...th-the-euro-spec-gladiator.60762/post-1001112

 

[ShadowsPapa]

And how does the transfer case controller interact with the ABS system?
No other PCM or ABS changes are needed?

I know this was looked into by another person and found to be way beyond putting parts in and plugging it in.
Was he wrong?

The ABS would need to communicate with the transfer case controller.

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