MP3022 transfer case inside pictures ??

[onfire392]

Any pictures or videos of our transfer case internals ??

 

[onfire392]

Rough

 

[onfire392]

Rough

 

[stumblinhorse]

Here you go

 

[Turboencabulator]

I think of it more like this:

So there is this low speed and high speed hamster attached to 470 lb-ft of torque.... and....

All kidding aside, good post, nice to learn about this. One thing is I don't think crow hop is an issue in the 392 because it uses CV joints for the front wheel drive.

 

[stumblinhorse]

I think of it more like this:
View attachment 34296
So there is this low speed and high speed hamster attached to 470 lb-ft of torque.... and....

All kidding aside, good post, nice to learn about this. One thing is I don't think crow hop is an issue in the 392 because it uses CV joints for the front wheel drive.

It doesn’t crow hop because the clutches slip the front drive.

 

[Turboencabulator]

It doesn’t crow hop because the clutches slip the front drive.

I'll be the first to admit that I have no clue what's actually happening in the 3022 transfer case (see hamster GIF) so I'm sure you're probably right.

But I guess I was under the impression the whole reason for sacrificing the durability of a U-joint and going with a CV-joint was the fact that it is a constant velocity joint, so in 4H Auto the 3022's Drive Train Control Module (DTCM) can engage the front drive anytime it detects wheel slip regardless if the vehicle is turning or not. Here is a video talking about it in the 392:

 

[ParadigmDawg]

I think of it more like this:
View attachment 34296
So there is this low speed and high speed hamster attached to 470 lb-ft of torque.... and....

All kidding aside, good post, nice to learn about this. One thing is I don't think crow hop is an issue in the 392 because it uses CV joints for the front wheel drive.

Nothing can crab walk like an AMG. My highly modded GLC 63s was the best at it. My E63s wasn't near as bad.

 

[guruman]

I'll be the first to admit that I have no clue what's actually happening in the 3022 transfer case (see hamster GIF) so I'm sure you're probably right.

But I guess I was under the impression the whole reason for sacrificing the durability of a U-joint and going with a CV-joint was the fact that it is a constant velocity joint, so in 4H Auto the 3022's Drive Train Control Module (DTCM) can engage the front drive anytime it detects wheel slip regardless if the vehicle is turning or not. Here is a video talking about it in the 392:

I'm not sure there's a sacrifice with CV's over U-joint. I suspect most of the time it's a cost decision.

U-joints at full angle do rotate at uneven speeds. That causes a loading and unloading of torque during rotation (this is not necessarily the crow hop you'd get). This is why most axle u-joints fail at full turn (and full throttle). The CV does not do this, so it's less susceptible to failing at full angle. If the CV is engineered correctly, it will transfer as much power as the U-joint, but do it smoothly.

A note on crow hop for fun: it comes from the tires gripping a high friction surface. When Turing the front tires travel in a wider arc than the rear tires. When the front and rear axle are locked together, the tires are forced to slip a bit to account for the travel distant difference between the front and rear.

I once had an old CJ that blew a rear driveline, and I had to drive it around for a few days using the front axle only. Without the rear axle being linked to the front, there was no crow hopping in tight turns and I was not even able to notice the U-joint loading/unloading at all.

 

[stumblinhorse]

I'll be the first to admit that I have no clue what's actually happening in the 3022 transfer case (see hamster GIF) so I'm sure you're probably right.

But I guess I was under the impression the whole reason for sacrificing the durability of a U-joint and going with a CV-joint was the fact that it is a constant velocity joint, so in 4H Auto the 3022's Drive Train Control Module (DTCM) can engage the front drive anytime it detects wheel slip regardless if the vehicle is turning or not. Here is a video talking about it in the 392:

If you plug in a JScan and watch live features, you see the amount of force applied to the front drive reduced while you are sitting still, just by turning the wheel. I think @onfire392 mentioned someone posted a video of that somewhere. That is why the off road pages knows about steering angle. It uses it in the control module to try to determine how much to slip…

 

[Turboencabulator]

A note on crow hop for fun: it comes from the tires gripping a high friction surface. When Turing the front tires travel in a wider arc than the rear tires. When the front and rear axle are locked together, the tires are forced to slip a bit to account for the travel distant difference between the front and rear.

OK... I get it now. Thank you @guruman and @stumblinhorse! So, just to put it in hamster terms the front and rear hamsters are now running at different speeds during a turn and we've seen how that goes.

I guess I always think of turns as impacting the wheel rotation speed between the the left and right side of a vehicle which is compensated by the center differential. I didn't comprehend that the front and rear axles are also traveling at different speeds. Seems like the back is just following the front, but turns out that's not the case. Here is a great video explaining the engineering behind 4H-Auto vs 4H Part-Time vs 2H. It does a good job of demonstrating the "Wind-Up Phenomenon".

I have been learning a lot about the Atlas transfer case. While it may be a lot more bulletproof without the 4H Auto clutches that seem to fail in the mp3022. Turns out I really like how planted the 4H-Auto system feels in the factory transfer case. For everyday use I think the 4H-Auto is ideal. The only drawback I see is wear and tear and ultimately reliability. But with the MoparMAX $0 deductible warranty that's an issue for year 8. It looks like I can pickup a new mp3022 transfer case for around $2000, and it's relatively easy to swap when I'm out of warranty. I guess I'll just stay with the factory option. Maybe the Tazer in Forced Rear Wheel drive with a beefier rear axle is the way to go longterm.

 

[onfire392]

If you plug in a JScan and watch live features, you see the amount of force applied to the front drive reduced while you are sitting still, just by turning the wheel. I think @onfire392 mentioned someone posted a video of that somewhere. That is why the off road pages knows about steering angle. It uses it in the control module to try to determine how much to slip…

Also interesting is how it throws the clapping force at it HARD doing a full stop WOT launch, then backs off the clamping force after a few mph even though it is still WOT in 4A

Through IT searches, the MP3022 has been around a long time and in many platforms. !000's out there. Smalll set of failures that make zero sense. Some fail being babied for a couple 1000 miles. Some are beat to death on heavy weight 38" wheel/tire packages and don't break. Crazy. Shows the internal gears are strong, but using 4A in the wrong area and not changing the oil (and checking the level) can increase the failure rate.

 

[onfire392]

4 Part time at wot shows a much higher clamping force at 60mph than 4A shows.....even though both are decaying the rate.

 

[onfire392]

Even though he says (then edited) viscous coupler.....to clutch .....this looks very close to our MP3022

 

[onfire392]

Here you go
View attachment 34294

Is 17 the clutch pack ?

 

[Turboencabulator]

Is 17 the clutch pack ?

It looks to me like #17 is the "Transfer Case Output Shaft" (Mopar# 68391524AC) it looks like it uses a viscous coupling to engage the front wheels that is electronically actuated via a worm gear #45 called the "Gear Motor Worm Shaft" (Mopar# 68391529AA) which is turned by an small electric motor #39 called the "Transfer Case Actuator" (Mopar# 68391530AA).

So when the "Computer" called the "Transfer Case Control Module" (Mopar# 68547694AC) determines from the wheel speed sensors that power is needed at the front wheels it commands the actuator to turn the worm gear that compresses the viscus coupling and drives the forward output shaft. There is only one other electrical part, a small plunger sensor called the "Transfer Case Switch" (Mopar# 5083138AA) that senses what range (4H, 4L, 4H-Auto) the transfer case is in based on how far the liner sensor is pushed in. I don't know if Jeep uses this exact same sensor on the 392 but this is how a liner sensor works:

Kinda cool how it all works. Now the Tazer Forced Rear Wheel Drive makes a lot more sense! Basically you're just telling the Transfer Case Control Module to ignore wheel slip and stay in 2H. That would cut down on wear and tear on the Transfer Case Actuator and especially on the clutch disks within the Transfer Case Output Shaft. If only there was a button you could just press to turn off 2H and go back into 4H-Auto as needed. I don't have a Tazer yet because I haven't "needed" one, but when I eventually get one I'm going to try and figure out how to remap the "Mute" button and turn it into the Smokey Burnout button (aka 2H)

Here is a great video covering the Tazer forced Rear wheel drive and button mapping:

 

[Ted392]

To add to this, humvees had 3 different versions of tcases, none had clutches nor 2wd, All had high lock, high, low lock settings.
NP218 original, under built.
NP242 improved, very durable, at least 2 versions, lastest being the 4 bolt tail cone. Output shaft slip yoke (can be pinned). This tcase with lockers is durable.
MP2225 made for heavy armored 1151/52/65/67 series trucks. Beefy. Also used in civi trucks. Slip yoke.

Point to all of this, that I was able to install a 242 into a AMC S/X4 with a 390ci and 700r transmission and go places... so if the bolt pattern and spline count to the input shaft and housing are the same (if not, maybe changable), another 392 tcase option, without 2wd is the MP2225.

 

[Ted392]

Forgot to mention that the 242 can be modded for 2wd. Not sure yet on the 2225

 

[onfire392]

THE SILVER PUMP sits on top of the Black Viscous / Clutch drum coupler. That's where the magic happens. That's also where the failures began to happen is used improperly......burn that multi clutch disk unit up and the material contaminates the gears and chain and boom. Overall, the unit looks very strong.....especially the gears and chain. A 2H option on the shifter would have been perfection for clutch life. The electronic actuator could cause issues as well if it sporadically applied the clutch and wore it out. Overall I like the design. I am going to change the oil in the TC every year as a precaution since it is cheap and simple and will let me see if any clutch chunks are showing up.....plus keeps the gears and chain in fresh , non contaminated fluid.

 

[onfire392]

To add to this, humvees had 3 different versions of tcases, none had clutches nor 2wd, All had high lock, high, low lock settings.
NP218 original, under built.
NP242 improved, very durable, at least 2 versions, lastest being the 4 bolt tail cone. Output shaft slip yoke (can be pinned). This tcase with lockers is durable.
MP2225 made for heavy armored 1151/52/65/67 series trucks. Beefy. Also used in civi trucks. Slip yoke.

Point to all of this, that I was able to install a 242 into a AMC S/X4 with a 390ci and 700r transmission and go places... so if the bolt pattern and spline count to the input shaft and housing are the same (if not, maybe changable), another 392 tcase option, without 2wd is the MP2225.

NP242 is cool in Jeep or H1 mode. H1 is super cool with 32spline shafts and 6 pinions. Crazy strong. I wonder how 4A works with a 48/52 bias ? Basically it would have to be “locked” at that bias since there is not a clutch pack ??