Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Grand Cherokee - WK2 - (http://www.jeepgarage.org/f73/)
-   -   New transmission to have 9 speeds? (http://www.jeepgarage.org/f73/new-transmission-to-have-9-speeds-22719.html)

Lingohocken 05-03-2011 05:02 PM

New transmission to have 9 speeds?
 
According to today's Detroit News, all-wheel drive Chrysler products are to get a nine-speed box (by 2013). The 8-speed unit will be for rear-wheel drive models only. No mention this time of a six-speed option.

Which goes to show that you can't get too excited about these press reports, which are almost guaranteed to differ from each other from one month to the next. Who knows what will actually materialize, but Chrysler really needs to get a handle on its media communications.

Chrysler hopes to set its vehicles apart with new, 8-speed automatic transmissions in its rear-drive cars this year and 9-speed automatics in its front- and all-wheel-drive vehicles by 2013.
The multi-speed transmissions will improve fuel economy as much as 12 percent, which will help the carmaker compete for sales amid high gasoline prices."

jp467 05-03-2011 05:19 PM

Re: New transmission to have 9 speeds?
 
The 9 speed is a front wheel drive trans. The jeep will get the 8 speed rear wheel drive trans. The AWD they are talking about would be those on a FWD platform like a minivan. There is no 6 speed coming that's just a rumor someone started. It will be the 5 speed until the 8 speed comes.

capitalst 05-03-2011 05:19 PM

Re: New transmission to have 9 speeds?
 
Interesting....

Bmwister 05-03-2011 09:42 PM

Re: New transmission to have 9 speeds?
 
I was discussing the 545RFE transmission (comes with the Hemi) with an old engineering friend. He emphatically stated that with the existing three planetary gear sets in the 545FRE, Chrysler should be able to get eight (8) forward ratios from it through programming. The 545RFE is essentially the same as the older 45RFE that was re-flashed to add a second overdrive ratio, a 5th gear, so perhaps Chrysler will just reprogram the 545RFE to......an 645RFE or 745RFE? Eight rations would be annoying and far too many for little gain at the expense of increased wear and tear on the internal clutches, IMHO.

Who am I to doubt an old powertrain engineer and above all, I would rather have a tried and proven transmission like either of the WK2 5spd units than something entirely new. A new engine is one thing, but a transmission is what catches the most hell/abuse on a vehicle and for me that warrants more caution. FWIW, the 8spd in the Audi Q5 I looked at was terribly annoying with its constant shifting. Do we really want all those ratios disrupting the ride?

Lingohocken 05-03-2011 11:02 PM

Re: New transmission to have 9 speeds?
 
Quote:

Originally Posted by jp467 (Post 408557)
The 9 speed is a front wheel drive trans. The jeep will get the 8 speed rear wheel drive trans. The AWD they are talking about would be those on a FWD platform like a minivan.

Damn good point. Yet, by that reasoning and the content of the DN report, the WK2 arguably should be getting the 8-speed "this year."

Hardly likely. Presumably, then, the only rational conclusion is that they will start equipping some models with the 8-speed this year, with the remainder being upgraded at some future date. That scenario fits in exactly with Milous' feedback, which thus far has been the gold standard for accuracy.

The flurry of initial published reviews of the W2 virtually all concluded that the 5-speed box was responsible for the obvious slow performance at takeoff. They were all wrong, as the subsequent software tweak showed. If there's something approximating reasonable consistency throughout the power/RPM band, then an 8-speed box is not likely to make much difference in performance, even if it results in maybe a 2 mpg improvement.

Nice, but not a deal breaker.

jgc4ever 05-03-2011 11:15 PM

Re: New transmission to have 9 speeds?
 
http://en.wikipedia.org/wiki/ZF_8HP_transmission

jp467 05-03-2011 11:30 PM

Re: New transmission to have 9 speeds?
 
I would think if chrysler could get more usefull ratios out of the 545RFE they would. The new transmission that is coming is a ZF unit that chrysler will be building in their plant. From what I hear it is a very good unit.

Milous 05-04-2011 12:59 AM

Re: New transmission to have 9 speeds?
 
Quote:

Originally Posted by Bmwister (Post 408721)
...so perhaps Chrysler will just reprogram the 545RFE to......a 645RFE...

New 6-speed will be the "65RFE".

xcespwr 05-04-2011 09:44 AM

Re: New transmission to have 9 speeds?
 
Quote:

Originally Posted by Milous (Post 408817)
New 6-speed will be the "65RFE".

Confirmed for 2012 hemi?

jp467 05-04-2011 10:39 AM

Re: New transmission to have 9 speeds?
 
So my statement is wrong? They are going to have a six speed in between the 5 and 8 speed?

suzieque 05-04-2011 11:29 AM

Re: New transmission to have 9 speeds?
 
perhaps there is a future opportunity to retro fit the 8 speed to the current 545RFE equipped vehicles.

ColdCase 05-04-2011 11:35 AM

Re: New transmission to have 9 speeds?
 
Perhaps a 6 speed in 2012 with a reflash to 7 speed in 2013 with a reflash to 8 speed for 2014? Not that something similar has never happened before :)


All times are GMT -5. The time now is 02:34 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