Did I Selec track the wrong thing?

[ACAD_Cowboy]

To be fair, like costco, it's only a bargain if you can use it. I went with a rubicon for the deep gearing, lockers and disco. I dont mind awd systems at all but when out in it, I'm in it all the way through the storm. So for me a full time or awd system is of dubious use. BUT... for others its exactly what they wanted.

I think for most people the selectrac and lsd is really all they will use and thats just fine by me, you hoe your row, I'll hoe mine.

Sponsored

 

[Rubi_Rhod]

I had this transfer case in my Diesel Colorado. Its the same as in the grand and such. Slightly different numbers based on the specific torque application, but the same thing.

All it all it was phenomenal. That’s probably one thing I wish I had a ‘21 for. 80k miles and I used the full time AWD all the time. It was flawless in anymode.

And while it uses clutches in auto mode, it also has physical engagement locks above 25mph and when shifted in the 4H or 2L part time modes.

Running bigger tires, you shouldn’t have issues with advanced wear as its not solely relying on clutch packs to lock into place.

 

[spectre6000]

And while it uses clutches in auto mode, it also has physical engagement locks above 25mph and when shifted in the 4H or 2L part time modes.

Running bigger tires, you shouldn’t have issues with advanced wear as its not solely relying on clutch packs to lock into place.

Elaborate on this, please.

 

[Rubi_Rhod]

Elaborate on this, please.

This is the technical documents for the MP30xx series. I wish to have found more specs and docs on it as its a cool transfer case, but its a part made my magna and OEMs taylor it.

And if I am wrong, my mistake. I have had a heck of a time finding out the particulars of this transfer case and literature from mopar on it.

https://evopower.ca/mrws/filedriver/MP3023_and_3024_Operation.pdf

 

[spectre6000]

So, I didn't realize it was a Magna unit (though I don't know it makes much difference) and thought it was from New Process. Regardless, my understanding is that A4WD (as it's called above) links front to rear with a clutch, and once it detects drivetrain bind, releases the clutch to allow slippage and keep everyone happy and in one piece. This is the traction favored strategy. That clutch actuation is controlled by software, and could just as easily go the other way: front axle disengaged until wheel slippage is detected, then lock up. This is the fuel economy favored strategy, and I've seen it discussed here and elsewhere in the Jeep context.

When you said it locks above 25mph, that is new and novel information to me, and seems counterintuitive, but you clearly have information I don't. Similarly, when you say it's not relying solely on the clutch when in 4hi/lo, that is also new information to me. What do you know that makes you say these things?

I'm not saying you're wrong. My understanding comes from a different unit in a different platform, and may not be the same here.

 

[Rubi_Rhod]

So, I didn't realize it was a Magna unit (though I don't know it makes much difference) and thought it was from New Process. Regardless, my understanding is that A4WD (as it's called above) links front to rear with a clutch, and once it detects drivetrain bind, releases the clutch to allow slippage and keep everyone happy and in one piece. This is the traction favored strategy. That clutch actuation is controlled by software, and could just as easily go the other way: front axle disengaged until wheel slippage is detected, then lock up. This is the fuel economy favored strategy, and I've seen it discussed here and elsewhere in the Jeep context.

When you said it locks above 25mph, that is new and novel information to me, and seems counterintuitive, but you clearly have information I don't. Similarly, when you say it's not relying solely on the clutch when in 4hi/lo, that is also new information to me. What do you know that makes you say these things?

I'm not saying you're wrong. My understanding comes from a different unit in a different platform, and may not be the same here.

I had the same discussion before on the Colorado forums digging for the same information, as its really not at all a simple search. New Process was who I thought It was too, but I believe Magna acquired them. And diamler also had a stake in them as well. Most of the detail is in service manuals for trans rebuilders. If you look at the link in the prior post, It has info on how the modes are engaged and what they do. In auto, its locked via clutch pressure, and in the part time modes, it's a mechanical lock. You can also search for MP3023/4 and find a couple other links to service and technical overviews as well.

 

[tommyp]

I had the same discussion before on the Colorado forums digging for the same information, as its really not at all a simple search. New Process was who I thought It was too, but I believe Magna acquired them. And diamler also had a stake in them as well. Most of the detail is in service manuals for trans rebuilders. If you look at the link in the prior post, It has info on how the modes are engaged and what they do. In auto, its locked via clutch pressure, and in the part time modes, it's a mechanical lock. You can also search for MP3023/4 and find a couple other links to service and technical overviews as well.

It looks from that diagram that the 3022 is just rated for less torque vs the 3/4. Probably the same operation which makes sense. I doubt it locks at 25mph in auto. It would defeat the purpose of the awd

 

[spectre6000]

So it allows more slip at lower speeds due to more steering input. It uses more clutch pressure at higher speeds for the opposite reason. When going in a straight line, it "returns to the 5% duty cycle" which can be a low or high torque value depending on whether the clutch is NO or NC... Later on down the document, it talks about "applying clutches", so that suggests a NO operation. That would make it 2wd running down the highway in a straight line... or mostly 2wd... Depends on what a 5% duty cycle works out to in terms of clutch pressure. Makes sense practically and from a MPG perspective.

So wherever it's set, it's locked with whatever a "transfer-case motor lock" is.

 

[tommyp]

So wherever it's set, it's locked with whatever a "transfer-case motor lock" is.

That wording is weird. I think what that motor does is lock the case into whatever gear is being selected. I believe the transfer case has a mechanical shifter with linkage to the case (I have seen a 3022 picture where there is an arm with a ball on it) but inside the case it just moves a switch which controls the electronic shifter actuation (motor lock in this case). In the liberty ones it was a dial no mechanical connection.

So If I am reading that correctly what it is saying is that when you move the tcase shifter into A4wd the motor is locking the case into 2H until it needs to redirect power. When it slips then it lets the clutches and the awd stuff do their thing.

 

[spectre6000]

The motor actuating the clutch pack has a lock on it. That motor moves to where it needs to be, and when not actively moving is locked in place. So you if it's shifted to 2wd, it opens the clutches and locks there. 4wd, it closes and locks there. A4WD, it moves around to whatever clutch pressure, and locks wherever it thinks it needs to be. So if the axles are moving at the same speed, it moves to the 5% position, and locks. Etc. That's how it reads to me...

 

[tommyp]

The motor actuating the clutch pack has a lock on it. That motor moves to where it needs to be, and when not actively moving is locked in place. So you if it's shifted to 2wd, it opens the clutches and locks there. 4wd, it closes and locks there. A4WD, it moves around to whatever clutch pressure, and locks wherever it thinks it needs to be. So if the axles are moving at the same speed, it moves to the 5% position, and locks. Etc. That's how it reads to me...

Yes you are right, just watched a teardown video of a 3023 case. I still can't figure out if it actually locks out the clutch pack mechanically or just tightens it down so much that it doesn't move. I would rather that there was some mechanical means to bypass the clutches but I didn't see anything like that in the mp3023. Just the lever/ramp controlling the pressure on the packs. I wish there was better documentation but it seems to me that the potential to cook the clutches even when "locked" in 4lo or hi is there. It is probably fine if the case puts enough pressure on the clutches the only issue is all the extra parts and complexity of this case.

I am not sure what I was thinking but its academic now as my gladiator is already built with the selec track. Rubicon cases aren't too expensive if I wanted to swap as long as the electronics are doable. The tccm would have to be swapped as there are different ones for the selec track and the part time cases. Not sure if any reprograming/flashing would be needed besides ratio change. Would the dealer have to activate/flash the module for the vin?

 

[spectre6000]

Link to vid?

Also, it occurs to me that I've not seen anything official indicating that this is the model in our trucks. Where does that datum come from?

From my reading of that document, there's no additional mechanism. Just the clutch pack. The lock is in the motor that actuates the clutch pack. I looked through the diagrams as well, and didn't see anything that looked like it even might be such a device. It's definitely not very well written though...

From the lit cited, you'd have quite a bit of electrical hook upping to do to go from the RockTrack to SelecTrack (assuming I spelled and formatted those correctly). Lots of intravehicular communication required to do what it does.

 

[tommyp]

Link to vid?

Also, it occurs to me that I've not seen anything official indicating that this is the model in our trucks. Where does that datum come from?

From my reading of that document, there's no additional mechanism. Just the clutch pack. The lock is in the motor that actuates the clutch pack. I looked through the diagrams as well, and didn't see anything that looked like it even might be such a device. It's definitely not very well written though...

From the lit cited, you'd have quite a bit of electrical hook upping to do to go from the RockTrack to SelecTrack (assuming I spelled and formatted those correctly). Lots of intravehicular communication required to do what it does.

Its a bit of a goat rodeo. Doesn't seem like the guy has pulled that type apart much before.

I would be going from selec-track to a more traditional case. I wish I knew more about the jeep can -bus setup and modules. I have done a bunch of swapping LS stuff etc but its hard for me to know what is doable or if its a pain in the ass with the newer stuff. I am just hoping that the case isn't a problem and works ok for what I am doing. Having the 392 with the same case eases my worries though. If that thing was speced with it they must have some faith in the case to hold up to abuse.

 

[Trippin01]

I guess you just trust the computer to decide what you need for traction. It might be excellent, so give it a shot. You already have it, so use it. Then update us.

 

[spectre6000]

Watching that guy is why I do not trust any of my machines to shops like that... When they tried to force the input shaft over out of plane to fit the chain on against the seal he previously described as being a bitch to install, then later admitted to having left the original in place, thus further wrecking the seal he didn't replace because it's a bitch to replace. There's plenty else to be unhappy with if that were my transfer case, but... geez...

Meanwhile, no. The clutches are actuated by the snail cam in the middle. Whatever is turning that combined with mechanical advantage is what is doing the locking. Still, I wouldn't sweat it. It's a decades old proven design, and the benefits outweigh the potential costs.

Sponsored