Overheating the 4x4 system

[AnthonyD1978]

Willow Springs?... I used to track there, and Fontana (Roval & 1/4 mile) and Irwindale - in a modified G35...

Like you, I decided AZ is about off-road - the G has been sitting in garage for 3+ years...

I am trying hard not to go down the rabbit hole with the Ram - but it's an addiction (any of us that have modified vehicles know this)... I told myself no mods - and in the first two weeks I'm two grand in (but all practical stuff).

I'll keep an eye on your build progress - looks like you have good insight.

Yes, that's big willow! I did the Roval at Autoclub too. That was my favorite track. Here I am there in my NISMO 370z which is a cousin to your g35.

My first two weeks of the truck I had wheels, tires, and the Mopar lift

Thx for sharing those hills are way bigger than they look on video. I could see your truck cutting in and out of 4x4.

The hills were like roller coaster rides. Video never does them justice.

I have the bypass switch in the works, but it won't be ready for about 4 weeks. The bypass switch will basically lock up the transfer case 100% when the switch is turned on. This should hopefully keep the clutch pack from constantly engaging/disengaging and then overheating. This coupled with BLDS and 4auto and I should have the best of both worlds. I should basically have 2wd, 4auto, 4HI, 4LO, and "Center Lock".

The consensus is that the BorgWarner transfer case is not the problem really. It's the way FCA coded it to behave. Which was for ease of use for the end-user.

 

[DesertRebel]

Yes, that's big willow! I did the Roval at Autoclub too. That was my favorite track. Here I am there in my NISMO 370z which is a cousin to your g35.

My first two weeks of the truck I had wheels, tires, and the Mopar lift



The hills were like roller coaster rides. Video never does them justice.

I have the bypass switch in the works, but it won't be ready for about 4 weeks. The bypass switch will basically lock up the transfer case 100% when the switch is turned on. This should hopefully keep the clutch pack from constantly engaging/disengaging and then overheating. This coupled with BLDS and 4auto and I should have the best of both worlds. I should basically have 2wd, 4auto, 4HI, 4LO, and "Center Lock".

The consensus is that the BorgWarner transfer case is not the problem really. It's the way FCA coded it to behave. Which was for ease of use for the end-user.

Nice.

The G has cams, headers, hi-flow cats, plenum spacer and port work, cat-back exhaust, UpRev tune by Shawn Church, Quaife diff with 3.69 gears - I put JWT valve springs and upgraded rod bolts, intending to go FI, but lost interest... suspension and brakes mods too...

The VQDE is a great motor. The Z and G are fun cars. And yes, the Roval is a blast! I don't miss many things about CA - but track days and car meets are something to be missed.

 

[AnthonyD1978]

Nice.

The G has cams, headers, hi-flow cats, plenum spacer and port work, cat-back exhaust, UpRev tune by Shawn Church, Quaife diff with 3.69 gears - I put JWT valve springs and upgraded rod bolts, intending to go FI, but lost interest... suspension and brakes mods too...

The VQDE is a great motor. The Z and G are fun cars. And yes, the Roval is a blast! I don't miss many things about CA - but track days and car meets are something to be missed.

Church did my tune on my S2000

 

[DesertRebel]

Church did my tune on my S2000

That's his wheelhouse for sure.

 

[Nails]

Great stuff, will be taking the time to read all up on this. Thank you

 

[Rob5589]

Great info on the tcase. I'd love to know the condition of the fluid in yours; dark, burnt, etc. Other than the bypass, I wonder if an alternative fluid would help with heat and slip.

 

[AnthonyD1978]

Great info on the tcase. I'd love to know the condition of the fluid in yours; dark, burnt, etc. Other than the bypass, I wonder if an alternative fluid would help with heat and slip.

If I remember correctly, RAM says that the TC fluid is life (or was it like 100k?). I'll be changing mine out sooner rather than later. I also question how the truck knows the TC is overheated. Is an actual temp sensor or some algorithm it uses? I bet it's an algorithm it uses to estimate. When it comes time I'll need to see if they have a full synthetic that meets the requirement of our TC.

Also, our 4auto TC is the BorgWarner 48-11. No longer the 44-44.

 

[Nails]

^^^ have to agree with you on algorithm. As I check multiple wiring diagrams and not seeing a temp sensor of any kind.
As for fluid- check into BG synchro shift. Its awesome stuff & full synthetic too.

 

[devildodge]

Sorry for the oversite...I got caught up in learning about the BLDS and the issues with the 44-44.

I will edit my above post.

48-12 part time transfer case in Tradesman and Rebel.

48-11 auto transfer case in Bighorn, Laramie, Longhorn, and Limited.

 

[AnthonyD1978]

^^^ have to agree with you on algorithm. As I check multiple wiring diagrams and not seeing a temp sensor of any kind.
As for fluid- check into BG synchro shift. Its awesome stuff & full synthetic too.

Thanks for the confirmation. I might buy an infrared temp gun to get an external temp reading on the TC when I do the testing on that bypass switch. I've always wanted one of those anyway.

I've been a Red LIne and Motul guy for a while now, but I'll look at BG too.

 

[Nails]

I’m a big fan of the temp gun. Don’t realize how many situations you can use it till you have it. Those products are top notch too!
For myself one of the best reasons to use BG is when done to spec intervals they pay parts and labor of most to all of it. Very little to no resistance. Yes, there is always small print like anything else. I’ve yet to come into a issue with denial of a failure claim. If the fluid touches it, it’s covered. Fluid doesn’t have to be proven of failure. Just my 2c

 

[CaptainCJ35]

The temp gun would answer a lot of questions... and I agree about the algorithm. I have a hard time wrapping my brain around a T-Case "locked" in 4-Low heating up significantly... unless it's never really locked in the first place and clutches are slipping, creating friction and thus heat... which is how e-LSD's get overheated on track days which has been mentioned as examples.

Poor programming that just assumes over heating based on cheery-picked data input seems more likely. Like it's only programmed for 4-Auto... 4-Hi and 4-Low don't cause a change in parameters. As I'm typing this, I feel like this is more and more likely (unfortunate cost cutting that many customers were never going to experience).

 

[devildodge]

Like was said. It was set up so anyone going down the road who hits 4wd will not cause damage as the clutches will slip and let happen the engagement of 4wd.

The transfer case never really locks, just applies a different parameter of pressure on the clutches even in 4wd low.

Some will never notice as their use falls into what the transfer case is set up to do.

Getting on and off the throttle is what allows the clutches to relax and hence causes the slippage which then causes the issue.

If this explanation comes across proper.

 

[devildodge]

I really believe eventually the Longhorn and Limited will just get an AWD setup.

The bighorn and Laramie will get the current setup.

Tradesman and Rebel will continue with the part time offering.

 

[AnthonyD1978]

UPDATE: I tested the first 5th gen prototype of the bypass switch last weekend. Unfortunately, it did not work as expected. I believe it's just a matter of time before he figures it out.

 

[Willwork4truck]

Guessing you have the 48-11 (44-44) AKA 4wd auto transfer case.

This is why the Rebel does not use this transfer case.

The 48-11 (44-44) uses clutches to engage 4wd, even in 4wd lock.

The 48-12 (44-45) in the Rebel uses a direct chain drive.

The 48-11 (44-44) never locks and actually switches in and out of 2wd 4wd while operating.

4 wheel low will help some, but you basically overheated the clutches.

Why i get so anxious when someone says it is stupid the Rebel doesn't offer 4wd auto.

My educated guess.

Love the bumper mod

Great explanation. I’d have not guessed that the -11 was clutched, but then, thinking about it, how else could the 4A work? So it’s a much weaker system, and obviously not meant for more serious off-roading.

Good to know (though short of navigating a blizzard I’ll never use it). It does make you wonder why it isn’t better explained though.

 

[Willwork4truck]

Great info on the tcase. I'd love to know the condition of the fluid in yours; dark, burnt, etc. Other than the bypass, I wonder if an alternative fluid would help with heat and slip.

It’s supposed to be a full synthetic isn’t it? That handles heat so much better.

 

[Chippy]

After following this thread and when you see other threads stating what’s the difference between a Rebel and X I sure hope there reading this thread !! It’s not about the money it’s knowing what the actual capabilities of your truck are and the intended use

 

[AnthonyD1978]

After following this thread and when you see other threads stating what’s the difference between a Rebel and X I sure hope there reading this thread !! It’s not about the money it’s knowing what the actual capabilities of your truck are and the intended use

Yeah, I ignorantly thought 4x4 meant 4x4. It should really be advertised as a really good AWD system. If they did that I might have put up with all the red in the Rebel interior lol. I would be in a new Power Wagon after all this, but now I'm waiting to see what the TRX is going to do. I will be in one of those as soon as the TRX drops and I can decide which to get.

Most people will never see this shortcoming. Enjoy your trucks!

 

[AnthonyD1978]

It’s supposed to be a full synthetic isn’t it? That handles heat so much better.

I doubt there is an actual temperature probe for the TC. It probably just uses some sort of algorithm to estimate the temp. So putting synthetic in won't matter (if it doesn't already have it).