Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Suspension/Driveline/Brakes/Wheels/Tires

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 12-19-2013, 06:34 PM
Premium Member
 
Join Date: May 2012
Posts: 127
Thanks: 14
Thanked 10 Times in 9 Posts
Rep Power: 819
200sxr is on a distinguished road
8 speed transmission behavior

Just want to validate the behavior of the transmission in paddle shift mode.

My GC is a export Diesel, here is what I have found;

* In paddle shift mode (and in both Sport mode and ECO mode) the transmission will kick down one gear; eg select a gear using the paddle, say with the engine speed around 1500rpm and if you go WOT the transmission will go down a gear.

* Again in paddle shift mode, the transmission will shift up a gear when it approaches the designed engine speed when a up shift occurs (~3700rpm - 3900rpm). The behavior is the same in either ECO or sport mode.

Is the behavior the same with the non diesel engines?
__________________

__________________
Aerodynamics are for people who can't build engines - Enzo Ferrari
Reply With Quote
  #2  
Old 12-19-2013, 09:17 PM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 1,993
Thanks: 40
Thanked 140 Times in 124 Posts
Rep Power: 4306
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 8 speed transmission behavior

Could just be my brain, but I have read that a few times and do not know what you are saying.

What does "WOT" mean?
__________________

__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #3  
Old 12-19-2013, 09:20 PM
jbjones85's Avatar
Premium Member
My Jeep: 2014 6.4L SRT8 WK2
 
Join Date: Feb 2012
Location: Raleigh/Durham NC
Posts: 672
Thanks: 9
Thanked 67 Times in 60 Posts
Rep Power: 1964
jbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond reputejbjones85 has a reputation beyond repute
I can't comment on the diesel part but wot is wide open throttle.
__________________
Reply With Quote
  #4  
Old 12-20-2013, 03:16 AM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 1,993
Thanks: 40
Thanked 140 Times in 124 Posts
Rep Power: 4306
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 8 speed transmission behavior

Thanks, it makes sense now.
So up and down shifting by itself when you are supposed to have manual control over it, and rather than hold a gear, it changes it.

Manual suggests it will do this

"In Paddle Shift 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 downshift 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."

I have not used the shifters, i will give it a try tomorrow.
__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #5  
Old 12-20-2013, 05:32 PM
Premium Member
 
Join Date: May 2012
Posts: 127
Thanks: 14
Thanked 10 Times in 9 Posts
Rep Power: 819
200sxr is on a distinguished road
Re: 8 speed transmission behavior

Yes WOT is wide open throttle, I guess it is a bit misleading as mechanically there is no real throttle in a diesel engine. Maybe I should just call it "flooring it"

What I have found in manual or paddle mode is the transmission will not hang on to the selected gear. It will down shift as I "floor it" and it will also upshift to the next gear as I approach the programmed up shift engine speed.

I understand the exception is as the car slows down or coming to a stop the transmission would shift down to the appropriate gear.

I really would prefer if I have selected a gear in manual mode the transmission would stay in that gear no matter what, just like a good old manual transmission.
__________________
Aerodynamics are for people who can't build engines - Enzo Ferrari
Reply With Quote
  #6  
Old 12-20-2013, 05:51 PM
bill_de's Avatar
Premium Member
My Jeep: 2014 5.7L WK2
 
Join Date: Sep 2012
Posts: 5,475
Thanks: 257
Thanked 257 Times in 228 Posts
Rep Power: 1800511
bill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond reputebill_de has a reputation beyond repute
Re: 8 speed transmission behavior

Have you tried it in Sport mode?

My last vehicle, non Jeep, would let the paddles over ride normal shift points when in sport, but not in drive.


---
__________________
If you need a shoulder to cry on ...

... pull over to the side of the road!

Reply With Quote
  #7  
Old 12-20-2013, 09:11 PM
Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jan 2013
Location: Michigan
Posts: 770
Thanks: 4
Thanked 16 Times in 11 Posts
Rep Power: 126959
loveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond repute
Our V6 will stay in whatever gear you command unless it will over rev the engine or lug the engine. If you put it in 8th gear going 40 and floor it it will stay in 8th gear.
__________________
Reply With Quote
  #8  
Old 12-20-2013, 09:31 PM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 1,993
Thanks: 40
Thanked 140 Times in 124 Posts
Rep Power: 4306
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 8 speed transmission behavior

I took the GC for a quick run up to Bilpin, to play with it through the twisty hill climb.'It changes up like it is in full auto mode.

Here is a video of it doing it in Sport mode. I selected first and it did the rest itself.
I didn't really try the downshift though. The two times i tried it wouldn't do it.

If it wasn't stupid enough to be filming this myself while driving I would have gotten the tacho in shot too.
Attached Files
__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #9  
Old 12-21-2013, 02:52 AM
Premium Member
 
Join Date: May 2012
Posts: 127
Thanks: 14
Thanked 10 Times in 9 Posts
Rep Power: 819
200sxr is on a distinguished road
Re: 8 speed transmission behavior

So it looks like the diesel transmission is programmed differently to the V6. It will not hold gear in paddle / manual mode in ECO, non ECO or sport mode which is a little bit disappointing!
__________________
Aerodynamics are for people who can't build engines - Enzo Ferrari
Reply With Quote
  #10  
Old 12-21-2013, 07:55 AM
Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jan 2013
Location: Michigan
Posts: 770
Thanks: 4
Thanked 16 Times in 11 Posts
Rep Power: 126959
loveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond repute
Quote:
Originally Posted by 200sxr View Post
So it looks like the diesel transmission is programmed differently to the V6. It will not hold gear in paddle / manual mode in ECO, non ECO or sport mode which is a little bit disappointing!
I have read conflicting stories on this. I have read of other people having theirs act just like yours. You are just limiting the top gear the transmission goes into. That makes sense to me because ours acts the same whether you use the paddles in sport mode or normal mode. To me it should act the way yours does in non eco mode and the way ours does in sport mode. If you want to limit your highest gear for towing or something like that all you do is put it in say 6th gear and it will go 1-6 all by itself, but if you want to control what gear it goes in, switch to sport mode and use the paddles and you can do that too.
__________________
Reply With Quote
  #11  
Old 12-21-2013, 08:10 AM
SNUKE's Avatar
Premium Member
My Jeep: 2014 3.0L WK2
 
Join Date: Jan 2013
Location: Sydney, Aus
Posts: 1,993
Thanks: 40
Thanked 140 Times in 124 Posts
Rep Power: 4306
SNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond reputeSNUKE has a reputation beyond repute
Garage
Re: 8 speed transmission behavior

But you can't get it to hold the gear selected, it won't hit a rev limiter it just shifts up.
I couldn't get it to drop into second for a tight corner, it would not drop lower than 3rd until it was past the point of use as an engine brake combined with actual brakes.
__________________
I'm just want it for the "shorter headlamps".

MY14 GC Limited, 3.0 CRD, Lux II, Granite Crystal, 18" Wheels, Tubular Side Steps.
Ordered: July 7 2013 Delivered Nov 25th
Reply With Quote
  #12  
Old 12-21-2013, 08:17 AM
Member
My Jeep: 2014 3.6L WK2
 
Join Date: Jan 2013
Location: Michigan
Posts: 770
Thanks: 4
Thanked 16 Times in 11 Posts
Rep Power: 126959
loveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond reputeloveracing1988 has a reputation beyond repute
Quote:
Originally Posted by SNUKE View Post
But you can't get it to hold the gear selected, it won't hit a rev limiter it just shifts up.
I couldn't get it to drop into second for a tight corner, it would not drop lower than 3rd until it was past the point of use as an engine brake combined with actual brakes.
In that respect the diesel might be differnt since you don't have true engine braking. It might be designed that way to control boost and such. Im thinking if you wanted a vehicle you can hustle around like that a grand cherokee with the diesel might not be your best choice.
__________________

__________________
Reply With Quote
Reply

Tags
8 speed

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
8 Speed Transmission Downshifting Behavior mswlogo Grand Cherokee - WK2 - 21 08-21-2013 06:49 AM
how to make the "6 speed" transmission in 2012 Hemi actually work as a 6 speed? mikoz Suspension/Driveline/Brakes/Wheels/Tires 8 05-29-2013 07:04 PM
8-speed transmission Christophe Grand Cherokee - WK2 - 3 02-09-2013 06:28 PM
8-speed transmission Christophe Export Grand Cherokee 2011+ 3 02-09-2013 09:02 AM
8-speed transmission ftffom Suspension/Driveline/Brakes/Wheels/Tires 6 10-25-2010 11:24 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:25 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community