MAKE SURE to be in MANUAL SHIFT when Wheeling in 4LO

wayoflife

wayoflife

Administrator
Staff member
JLU_RUBI said:
I had the same thing happen to me in my JKU on some really steep hills in NC.

I really think Jeep intended for people with the autos to use the manual mode. I didn't do it at first in my JKU but once I figured out that it held the gear through redline and would not shift until I wanted, it gave me all the control of a manual without having to work a clutch. I assume the ZF 8 spd is the same way. Once you get used to it, its great. But I can see how this could be a problem especially if it catches you off guard at the wrong obstacle at the wrong time.
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That was just the thing with me. I was backing up to get lined up better on an obstacle and just forgot that I wasn't in manual. Really surprised the hell out of me.

BillArnett said:
Thanks big time, Eddie! This is certainly not the behavior I would have expected. I'm sure your warning will save me some grief, if not something much worse.
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Like I said, just want to make sure others know about this so that they'll know how to prevent it.

RMC2 said:
Thanks for sharing. This could cause someone without your experience level an issue that could go south in a hurry.
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I agree. It was unnerving even for me.

Bueller44 said:
Eddie, did you have the Auto Start Stop on or off? Was the motor mistakenly shutting off even though your foot wasn't on the gas?
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Auto Start/Stop is OFF when in 4LO.
 

MrGiant

MrGiant

New member
This whole issue sounds really scary, but I expected something like this from an AT, since it is just not that intelligent to know what you want to do.
But now about this M-Gate: to shift up/down all you need to do is pull/push the shifter? Sideways like GC WK2 or like a sequential gearbox, like in rallye cars?
Unfortunately, I didn't get to see this feature in any video so far, but it is really interesting to me

Sent from my [device_name] using JL Wrangler Jeep Forum mobile app
 

wayoflife

wayoflife

Administrator
Staff member
MrGiant said:
This whole issue sounds really scary, but I expected something like this from an AT, since it is just not that intelligent to know what you want to do.
But now about this M-Gate: to shift up/down all you need to do is pull/push the shifter? Sideways like GC WK2 or like a sequential gearbox, like in rallye cars?
Unfortunately, I didn't get to see this feature in any video so far, but it is really interesting to me

Sent from my [device_name] using JL Wrangler Jeep Forum mobile app
Click to expand...

Unlike the JK before, you push the shifter to the side and then push it toward the dash to down shift and pull it back toward you to shift up.
 

O

offcamber

New member
Bueller44 said:
Eddie, did you have the Auto Start Stop on or off? Was the motor mistakenly shutting off even though your foot wasn't on the gas?
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It is disabled automatically in 4Low. Our Grand Cherokee is a diesel and doesn't have the Start Stop and it did it. It's something about the way the 8 speed Jeep auto works. It just ships into a gear too high to maintain the momentum but it won't downshift. It literally feels like the engine loses all power and this was with the 460ft/lbs of the ecodiesel for us.
 

BillArnett

BillArnett

New member
The JL Owners manual states: "In AutoStick mode, the transmission will shift up or down when (+/-) is manually selected by the driver unless an engine lugging or overspeed condition would result. It will remain in the selected gear until another upshift or down- shift is chosen, except as described below:
• The transmission will automatically downshift as the vehicle slows (to prevent engine lugging) and will display the current gear.
• The transmission will automatically downshift to first gear when coming to a stop. After a stop, the driver should manually upshift (+) the transmission as the vehicle is accelerated."

If this is correct (and I don't have all the much confidence in it) then I would have to conclude that the unintended shift the Eddie and others have experienced was an UPshift. Is that right?

Also, Eddie says the default when stopped in 2nd, not 1st. Maybe it's different in 4LO and the manual neglected to mention that?
 

wayoflife

wayoflife

Administrator
Staff member
If you're in 4LO, at a stop and shift into manual, D2 will show up on your dash. As in, you will be in 2nd gear. Not sure why this is but you can verify this for yourself.

My best guess is that the transmission is trying to upshift when this problem occurs but what I can tell you is that it feels more like the motor just cuts out.
 

BillArnett

BillArnett

New member
But maybe if you're already in M-mode ("AutoStick") and come to a stop it will go into 1st? Even if you're in some other gear before the stop? Screwy.

I didn't quote the whole thing in my previous post. Here's the whole section:

"In AutoStick mode, the transmission will shift up or down when (+/-) is manually selected by the driver unless an engine lugging or overspeed condition would result. It will remain in the selected gear until another upshift or down- shift is chosen, except as described below:
• The transmission will automatically downshift as the vehicle slows (to prevent engine lugging) and will display the current gear.
• The transmission will automatically downshift to first gear when coming to a stop. After a stop, the driver should manually upshift (+) the transmission as the vehicle is accelerated.
• You can start out, from a stop, in first or second gear (or third gear, in 4LO range). Tapping (+) (at a stop) will allow starting in second gear. Starting out in second or third gear can be helpful in snowy or icy conditions.
• If a requested downshift would cause the engine to over-speed, that shift will not occur.
• The system will ignore attempts to upshift at too low of a vehicle speed.
• Holding the gear selector in the (-) position will down shift the transmission to the lowest gear possible at the current speed.
• Transmission shifting will be more noticeable when AutoStick is enabled.
• The system may revert to automatic shift mode if a fault or overheat condition is detected.
NOTE: When Hill Descent Control is enabled, AutoStick is not active."

No mention of automatically upshifting. What else is missing?

It's annoying that we have to figure this stuff out by trial and error (especially when the error can be potentially dangerous). Why can't they just publish a full description of how the transmission's algorithm works??? It's almost enough to make me go back to a manual :-(
 

1

13_gecko_rubi

New member
BillArnett said:
But maybe if you're already in M-mode ("AutoStick") and come to a stop it will go into 1st? Even if you're in some other gear before the stop? Screwy.

I didn't quote the whole thing in my previous post. Here's the whole section:

"In AutoStick mode, the transmission will shift up or down when (+/-) is manually selected by the driver unless an engine lugging or overspeed condition would result. It will remain in the selected gear until another upshift or down- shift is chosen, except as described below:
• The transmission will automatically downshift as the vehicle slows (to prevent engine lugging) and will display the current gear.
• The transmission will automatically downshift to first gear when coming to a stop. After a stop, the driver should manually upshift (+) the transmission as the vehicle is accelerated.
• You can start out, from a stop, in first or second gear (or third gear, in 4LO range). Tapping (+) (at a stop) will allow starting in second gear. Starting out in second or third gear can be helpful in snowy or icy conditions.
• If a requested downshift would cause the engine to over-speed, that shift will not occur.
• The system will ignore attempts to upshift at too low of a vehicle speed.
• Holding the gear selector in the (-) position will down shift the transmission to the lowest gear possible at the current speed.
• Transmission shifting will be more noticeable when AutoStick is enabled.
• The system may revert to automatic shift mode if a fault or overheat condition is detected.
NOTE: When Hill Descent Control is enabled, AutoStick is not active."

No mention of automatically upshifting. What else is missing?

It's annoying that we have to figure this stuff out by trial and error (especially when the error can be potentially dangerous). Why can't they just publish a full description of how the transmission's algorithm works??? It's almost enough to make me go back to a manual :-(
Click to expand...
That is very detailed and describes everything. It will not automatically upshift, it will bump against rev limiter and stay there.

Publish the transmission algorithm? That's funny. There are dozens of different algorithms based in tons of things.

Sent via....
 

Cozdude

Cozdude

Guy with a Red 2-Door
Do we know if all auto JL’s come with the tap shift? I would assume yes cause if not the sport peeps would be SOL
 

BillArnett

BillArnett

New member
wayoflife said:
That's EXACTLY what it feels like - like hitting a rev limiter!!
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But I presume you weren't really at the redline, right? Maybe it's some sort of traction control thing where it thinks you're slipping because you're using too much torque so it decides it would be better to upshift (like starting from a stop on ice)? And being in AutoStick (aka M-gate, aka manual mode) disables this behavior ?
 

wayoflife

wayoflife

Administrator
Staff member
BillArnett said:
But I presume you weren't really at the redline, right? Maybe it's some sort of traction control thing where it thinks you're slipping because you're using too much torque so it decides it would be better to upshift (like starting from a stop on ice)? And being in AutoStick (aka M-gate, aka manual mode) disables this behavior ?
Click to expand...

Far from it. Couldn't have been more than 3k at most and I doubt even that.
 

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