4WD Auto

[Darksteel165]

I’m confused about the 4-Auto. If a TRX is full time AWD why the Auto?

4HI and 4Lo makes sense as does neutral. Standard 4WD modes.

People get hung up on the names.
AWD and 4A are the same thing.
There are tons of different AWD systems, but essentially most are RWD with some torque being applied to the front tires, and more power is sent if a slip it sent.
4WD\4x4 is a 50\50 split 100% of the time

 

[Dewey]

People get hung up on the names.
AWD and 4A are the same thing.
There are tons of different AWD systems, but essentially most are RWD with some torque being applied to the front tires, and more power is sent if a slip it sent.
4WD\4x4 is a 50\50 split 100% of the time

But if the TRX is in 4WD full time anyway shouldn’t the selector just have 4HI-4LO and Neutral?

Waiting for @Eighty to clear this up.

 

[crusher]

during winter mine is always on, during sumer i put it on when it rains

 

[Darksteel165]

But if the TRX is in 4WD full time anyway shouldn’t the selector just have 4HI-4LO and Neutral?

Waiting for @Eighty to clear this up.

View attachment 154529

No. The trx is awd with the ability to lock it 50/50.

 

[Dewey]

No. The trx is awd with the ability to lock it 50/50.

Do the TRX’s not already have full power to all four wheels evenly due to AWD?

The purpose of 4WD AUTO is to kick into 4WD when it senses the rear wheels are slipping. With a TRX that shouldn’t even apply because power is already fully to all four wheels.

Make sense?

 

[Dewey]

Makes a whole lot more sense after watching this video. Helps to see things with my own eyes.

TRX is AWD but the power from front to rear is variable in 4WD AUTO. 4HI is always 50/50 front/rear. Same in 4LO.

 

[Darksteel165]

Do the TRX’s not already have full power to all four wheels evenly due to AWD?

The purpose of 4WD AUTO is to kick into 4WD when it senses the rear wheels are slipping. With a TRX that shouldn’t even apply because power is already fully to all four wheels.

Make sense?

This is incorrect. 4A does not do a 50\50 split when it senses the rear wheels are slipping. It does whatever split it thinks it needs up to a between 99\1-50\50. That is why trucks with 4A still have 4HI to get a 50\50 split

Makes a whole lot more sense after watching this video. Helps to see things with my own eyes.

TRX is AWD but the power from front to rear is variable in 4WD AUTO. 4HI is always 50/50 front/rear. Same in 4LO.

I just said that

No. The trx is awd with the ability to lock it 50/50.

"the power from front to rear is variable" is essentially the definition of 4A and AWD. No AWD vehicle does a 50\50 split as that is not AWD, that's 4WD which is very different. You wouldn't be able to drive a car\truck that was always 50\50, a TRX would rip it's tires right off as you went to turn if it was always 4WD.
Even my 2006 G35x would always give almost of the power to the rear wheels even though it is AWD. I had a button and I could force a 50\50 split, they called it snow mode.

 

[CalvinC]

I’ve had two Tundras and spent more time than I should have on Tundras.com and never heard any complain about T case overheating.

Lol. That ironically mirrors some of the OP's accounts of the standard tcase on hus buddy's Ram overheating while his own 4A case never did.

Never owned a Tundra so I dont spend time on the forums, but I was referring to old fashioned magazine articles in Car and Driver, Truck Trend, and Petersen's Off-road (or similar, can't recall), plus a TFL video, citing tcase overheating warnings when the TRD Pro came out.

Edit: Just found one of the old articles I was remembering... turns out mis-remembering. It was Motor Trend (not Truck Trend) and it was the Transmission overheating (Not the tcase).

 

[Dewey]

I’ve built motors and transmissions in the past but never touched a transfer case. This is some fascinating stuff and really enjoy these animations.

 

[H2OMAN]

It's kind of a shame they put this on the G/T. Taking the Rebel a step backward.

 

[Biga]

The TRX has an upgraded system per the below from Car and Driver.

X is equipped with a BorgWarner 48-13 full-time active transfer case with upgraded internals (extra clutch plates, a heavier-duty clutch apply bearing, six-pinion planetary low-range gear and a 20 percent wider, more robust chain). Other improvements include a new main shaft, new longer rear case half shaft to accommodate component changes and a rear output flange that replaces the slip yoke. There are nine different drive modes in total - Sport (25-percent:75-percent torque split), Snow (45:55), Tow (30:70), Auto (45:55), Custom (40:60), Mud/Sand (50:50), Rock (50:50), Baja (45:55) and Valet–that employ a unique calibration.

 

[Playmaker10]

It sounds like a lot of the problems happening with the clutch transfer case happen in 4uto.
Could this be avoided in those transfer cases by just using 4high or 4low and not using 4auto?

If not, can we swap transfer cases? Has anybody done this yet?

 

[H2OMAN]

It sounds like a lot of the problems happening with the clutch transfer case happen in 4uto.
Could this be avoided in those transfer cases by just using 4high or 4low and not using 4auto?

If not, can we swap transfer cases? Has anybody done this yet?

I've not heard of anyone doing it. It will be interesting to find out.

 

[kdoublep]

I use 4 auto whenever I get an excuse. No problems or strange noises yet. About change diffs and transfer case fluids. We'll see soon.

 

[MO Rebel]

But if the TRX is in 4WD full time anyway shouldn’t the selector just have 4HI-4LO and Neutral?

Waiting for @Eighty to clear this up.

View attachment 154529

Nope, 4WD Auto in the TRX is the default just like 2WD is in ours. You can switch to 4WD High or 4WD Low, but not 2WD.

 

[CalvinC]

I believe there was one guy on here who was looking into swapping the 4A case to the non4A case. One of the first guys to report overheating here. Never heard back so probably didn’t happen?

I do know on the F150, which uses the same tcase, folks go the other direction fairly often - putting the BW 4A case into trucks that only came with the 4H case (XLT and below trims). The 4A is actually the desirable one, particularly the Hi-Loc case from the Raptor.

So anythting can be done.

 

[HSKR R/T]

Nope, 4WD Auto in the TRX is the default just like 2WD is in ours. You can switch to 4WD High or 4WD Low, but not 2WD.

You can actually do 2wd with TRX transfer case if using a TazerDT.

 

[Darksteel165]

You can actually do 2wd with TRX transfer case if using a TazerDT.

In a world full of sensors you can do anything with (insert obscure item here) to be fair.

 

[HSKR R/T]

In a world full of sensors you can do anything with (insert obscure item here) to be fair.

TazerDT isn't an obscure item. But it just shows the TRX transfer case is capable of 2wd, RAM just doesn't give you the option from the factory. It's basically just a slightly more heavy duty version of the 4-auto transfer case in the 1500s

 

[CalvinC]

It's basically just a slightly more heavy duty version of the 4-auto transfer case in the 1500s

Interesting. Wonder if then its the same case as in the Raptor then. Because that's just the same tcase as the regular F150s with 4A (which is the same tcase as the Ram's with 4A), but they beefed it up enough to give it a separate part number & name.