For owners ... how is the awd??

jack bauer

Well-Known Member
Joined
Sep 12, 2018
Messages
275
Reaction score
307
Location
CA
Vehicle(s)
22 392XR incoming..
Occupation
Finance
4Auto is default, I believe it's the same Rock-Trac FT case (MP3022 4:1) with 2 hi left off the selection.
Does 4Auto mean that there is always power to the front wheels or only under certain conditions?
Advertisement

 

GATORB8

Well-Known Member
First Name
Matt
Joined
May 30, 2021
Messages
1,747
Reaction score
1,947
Location
CLT NC
Vehicle(s)
21 JLUR 4xe
Does 4Auto mean that there is always power to the front wheels or only under certain conditions?
On the Rub FT RT in 4Auto, the FAD is connected all the time, and the T-Case is in 2Hi normally. When wheel slip happens, it shifts to 4hi (quickly) and back to 2hi when slip stops.
 

jack bauer

Well-Known Member
Joined
Sep 12, 2018
Messages
275
Reaction score
307
Location
CA
Vehicle(s)
22 392XR incoming..
Occupation
Finance
On the Rub FT RT in 4Auto, the FAD is connected all the time, and the T-Case is in 2Hi normally. When wheel slip happens, it shifts to 4hi (quickly) and back to 2hi when slip stops.
Got it.
Thank you!
 

Young04

Well-Known Member
Joined
Mar 12, 2018
Messages
684
Reaction score
639
Location
MA
Vehicle(s)
Hydro Blue 392
So would you say on road in say a snow storm an audi with awd would be far superior to a JL in 4 hi or 4 auto?
Yes, I think so in most circumstances. However, I think it has more to do with the solid axles (slip on one side will get "transmitted" to the other side whereas in a vehicle with independent suspension that does not happen as much). In your usual snowy roads, an AWD vehicle seems more stable. The Jeep is better at getting unstuck.
 

Wbino

Well-Known Member
First Name
Walter
Joined
Mar 15, 2021
Messages
531
Reaction score
810
Location
Shore
Vehicle(s)
2021 Wrangler JL H.A. -- 1999 SLK 230
Occupation
Retired
The Full Time cases aren't AWD, they are Automatic 4wd Hi. No center differential.

Runs in 2wd until slippage is sensed, then shifts to normal 4hi.
Would it have killed them to show that it is activated and shows slippage?

My 1999 rwd does it....🙄

Since I don't really know when it's activated I have no opinion yet....but it has been spring/summer.
 

MSparks909

Well-Known Member
First Name
Miles
Joined
May 6, 2021
Messages
223
Reaction score
308
Location
NC
Vehicle(s)
JLU Rubicon 3.0
The 392 has a 2.72:1 low range where as the other 4Auto Rock-Trac in standard Rubicons and the 4XE has a 4:1 low range and 2H.
 

oldcjguy

Well-Known Member
First Name
Jim
Joined
Aug 26, 2020
Messages
302
Reaction score
345
Location
Central FL
Vehicle(s)
16 Challenger Hellcat, 19 Challenger Scatpack, 20 JLUR Recon
Occupation
Software Engineer
On the Rub FT RT in 4Auto, the FAD is connected all the time, and the T-Case is in 2Hi normally. When wheel slip happens, it shifts to 4hi (quickly) and back to 2hi when slip stops.
I don't think that's how it works. If it shifted into normal 4Hi then the front and rear axle are effectively locked together and both axles would be spinning at the same speed. No slipping. The tcase wouldn't know when to shift out of 4 hi. There needs to be some kind of clutch in the tcase to allow the slip so the front axle and the rear axle can spin at different speeds or the driveline would bind up. Otherwise going through turns would bind the system and it wouldn't be able to shift itself out of 4hi.

BTW I'm not trying to start an argument, I'm just thinking out loud. In truth I don't know exactly how the system works. I've heard they stiff have a FAD which just blows my mind. Not the way I would have done it, but I hear it works well.

As for durability they put it's behind the 392 and the 4xe (those electric motors with the 2.0T makes for a lot of torque) so... That should say something. Supposedly the 392 doesn't have a 2Hi option on the shifter. It only has 4Auto, 4Hi and 4Lo
 

AcesandEights

Well-Known Member
First Name
Aces
Joined
Aug 19, 2021
Messages
476
Reaction score
837
Location
So. Oregon
Vehicle(s)
2021 Jeep Rubicon 2D
Yeah, auto-shifting into 4hi would defeat the purpose of having an auto setting. That would be a 50/50 torque split and worse in rain/slush/snowy conditions on the highway.
 

GATORB8

Well-Known Member
First Name
Matt
Joined
May 30, 2021
Messages
1,747
Reaction score
1,947
Location
CLT NC
Vehicle(s)
21 JLUR 4xe
I don't think that's how it works. If it shifted into normal 4Hi then the front and rear axle are effectively locked together and both axles would be spinning at the same speed. No slipping. The tcase wouldn't know when to shift out of 4 hi. There needs to be some kind of clutch in the tcase to allow the slip so the front axle and the rear axle can spin at different speeds or the driveline would bind up. Otherwise going through turns would bind the system and it wouldn't be able to shift itself out of 4hi.

BTW I'm not trying to start an argument, I'm just thinking out loud. In truth I don't know exactly how the system works. I've heard they stiff have a FAD which just blows my mind. Not the way I would have done it, but I hear it works well.

As for durability they put it's behind the 392 and the 4xe (those electric motors with the 2.0T makes for a lot of torque) so... That should say something. Supposedly the 392 doesn't have a 2Hi option on the shifter. It only has 4Auto, 4Hi and 4Lo
? You can shift into and out of 4 hi whenever you want, the clutch simply disengages.

It’s just using the wheel speed sensors to tell it when to shift in and out.
 

supermike

Well-Known Member
First Name
mike
Joined
Sep 14, 2018
Messages
548
Reaction score
831
Location
Irvine CA
Vehicle(s)
18 JLUR 6 speed 2021 JLUR 392
Wet clutch is just a CHEAPER way to replace the job of mechanical center differential (Torsen/lockable/LSD) when trying to achieve AWD, thus they are called 4H Auto, not AWD.

Yes it's smooth, I can cornering way faster and under way heavier throttle in heavy rain in my 392 and not sliding a bit. It's heavenly on pavement specially in rain and snow spots. However it's durability and longevity is really unknow.......
 
OP
OP
thegame81

thegame81

Well-Known Member
Joined
May 24, 2021
Messages
222
Reaction score
433
Location
NJ
Vehicle(s)
Xtreme Recon 392
Wet clutch is just a CHEAPER way to replace the job of mechanical center differential(Torsen or lockable).

Yes it's smooth, I can cornering way faster and under way heavier throttle in heavy rain in my 392 and not sliding a bit. It's heavenly on road specially in rain and snow pavement. However it's durability and longevity is really unknow.......
Mike wondering worst case scenario say that does eventually need to be replaced or repaired what type of money are we talking ? I plan to keep mine long term.

Thanks !
 

AcesandEights

Well-Known Member
First Name
Aces
Joined
Aug 19, 2021
Messages
476
Reaction score
837
Location
So. Oregon
Vehicle(s)
2021 Jeep Rubicon 2D
Probably $2,500 - $3,200 plus labor. It won't wear out in your lifetime.
 
OP
OP
thegame81

thegame81

Well-Known Member
Joined
May 24, 2021
Messages
222
Reaction score
433
Location
NJ
Vehicle(s)
Xtreme Recon 392
Probably $2,500 - $3,200 plus labor. It won't wear out in your lifetime.
I can deal with that. I come from the gtr world. 3200 sounds amazing lol can't wait to get this thing!
 
Advertisement

Extreme Terrain
 
Advertisement
Top