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-   -   Transmission not automatically shifting into 7 and 8th gear (http://www.jeepgarage.org/f107/transmission-not-automatically-shifting-into-7-and-8th-gear-69130.html)

mswlogo 12-13-2013 03:49 AM

Transmission not automatically shifting into 7 and 8th gear
 
It's wicked cold out tonight, about 0 F.

I just did a 250 mile round trip.

It was 20 F on the way up and dropped steadily to around 10 F

and all was fine.

On the way home it was about 0 to start with and went up to about 10 F as I headed south.

On the trip home I'd climb a small incline and it would down shift into 6 or 7 with the cruise.

After I reach the crest. It stayed in 6th even going down hill at 65 mph.

I switch eco mode off and on and sport mode. They all stayed in 6th.

I'd goose it down to 5th or 4th and it would stop at 6th.

Finally used paddle shifters and it up shifted fine.

Then I'd kick it down and it would up shift back to 8th.

Next incline it'd do it again.

Also on one incline I want to pass a semi. Push the peddle and nuttin. No down shift at all. It was 3/4 down and no down shift. I learned not to push it further or it will kick down to 2nd or 3rd going 65 MPH. I waited a little bit and then tried again and it kicked down to 6 or 7th with a gentle tap.

I have the latest TSB's.

It seemed the cold temp stirred something up.

By the time I got home it would be in it's normal 8th gear at around 42 MPH

Has anyone seen this?

I hate taking shit like this to a dealer. Sorry we can't reproduce it.

2014RedHemiGC 12-13-2013 10:30 AM

Re: Transmission not automatically shifting into 7 and 8th gear
 
Most automatics are programmed to delay the upshift when going down hill, but the other behavior you describe sounds strange. BTW, I never use cruise on inclines, drinks too much gas trying to maintain the set speed.

lstowell 12-13-2013 04:33 PM

Re: Transmission not automatically shifting into 7 and 8th gear
 
The OP has something wrong.
Although I've noticed that even in ECO mode when wandering up and down [say like over the capitol reefs] it may stay in 6th or 7th longer before going to 8th, the no downshift smells like big troubles in the transmission or controller.

As for those temperatures, its been below zero for days and once the vehicle is warm, I've had no trouble with down shifts or getting into the higher gears on the freeways in Colorado.

Have a dim recollection it may inhibit higher gears until up to full operating temperature like the older 4-5 speeds did, as well as full throttle downshifts, but
once operating temps are reached, shouldn't be doing what it appears to be doing.

mswlogo 12-13-2013 06:53 PM

Re: Transmission not automatically shifting into 7 and 8th gear
 
Quote:

Originally Posted by lstowell (Post 944859)
The OP has something wrong.
Although I've noticed that even in ECO mode when wandering up and down [say like over the capitol reefs] it may stay in 6th or 7th longer before going to 8th, the no downshift smells like big troubles in the transmission or controller.

As for those temperatures, its been below zero for days and once the vehicle is warm, I've had no trouble with down shifts or getting into the higher gears on the freeways in Colorado.

Have a dim recollection it may inhibit higher gears until up to full operating temperature like the older 4-5 speeds did, as well as full throttle downshifts, but
once operating temps are reached, shouldn't be doing what it appears to be doing.

This was like after 40 miles. And it would go to "Normal" behavior if I reminded it, that it had 7th and 8th with the paddle shifters. For a short while.

I could step on it and it would shift normally down and back up to 8th shortly after forcing it up to 8th with the paddle and then disabling the paddle.

It's like this long stretch of no shifting with it real cold, made it numb.

I think a sensor is misreading due to low outside temp or a controller misbehaving.

I think Transmission was 156 like degrees. It stayed there for the entire 120 mile trip.

This morning with temps in low 20's it behaved normal.

curtispwns 01-09-2014 09:10 PM

Re: Transmission not automatically shifting into 7 and 8th gear
 
Quote:

Originally Posted by mswlogo (Post 944605)
It's wicked cold out tonight, about 0 F.

I just did a 250 mile round trip.

It was 20 F on the way up and dropped steadily to around 10 F

and all was fine.

On the way home it was about 0 to start with and went up to about 10 F as I headed south.

On the trip home I'd climb a small incline and it would down shift into 6 or 7 with the cruise.

After I reach the crest. It stayed in 6th even going down hill at 65 mph.

I switch eco mode off and on and sport mode. They all stayed in 6th.

I'd goose it down to 5th or 4th and it would stop at 6th.

Finally used paddle shifters and it up shifted fine.

Then I'd kick it down and it would up shift back to 8th.

Next incline it'd do it again.

Also on one incline I want to pass a semi. Push the peddle and nuttin. No down shift at all. It was 3/4 down and no down shift. I learned not to push it further or it will kick down to 2nd or 3rd going 65 MPH. I waited a little bit and then tried again and it kicked down to 6 or 7th with a gentle tap.

I have the latest TSB's.

It seemed the cold temp stirred something up.

By the time I got home it would be in it's normal 8th gear at around 42 MPH

Has anyone seen this?

I hate taking shit like this to a dealer. Sorry we can't reproduce it.

I have noticed the same thing while driving on the highway. The first time I just assumed it was really windy outside. Second time there was no wind.

mswlogo 01-10-2014 09:43 AM

Re: Transmission not automatically shifting into 7 and 8th gear
 
I believe the Rev-C update may of fixed this.
It's not a common scenario so I'm not 100 percent sure.


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