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-   -   Strange Shifting (http://www.jeepgarage.org/f181/strange-shifting-31340.html)

RiverCityOffroad 11-20-2011 01:56 AM

Strange Shifting
 
I have a 2010 WK HEMI. Please watch the video and notice when I manually shift from 2nd to 3rd there is a very, very small dip in RPMS at steady throttle.

http://www.youtube.com/watch?v=QdCUzFk6f0o

The Jeep doesn't shift right and surges on the road under normal, steady acceleration or travel. I decided to manually shift it and found that from 1 - 2 there's a large change in RPM, 2 - 3 almost none, and from 3 - 4 another large drop in RPM.

Can anyone else try this and see if my "3rd gear" in the auto is malfunctioning?

Thanks

FlyinRyan 11-20-2011 02:02 AM

Re: Strange Shifting
 
I cant tell...

Stock tune?

RiverCityOffroad 11-20-2011 03:57 AM

Re: Strange Shifting
 
It has a Predator on it right now - 87 Tune + MDS off. I'll take the Predator back off tomorrow and see if it still does it. I'm wondering if the tuner I have has issues...when it's on there the Jeep drives strangely. Going to remove it and update tomorrow.

Will report back.

I agree that it is difficult to see what I mean in the video. It drops about 300 RPM from 2nd to 3rd and then about 1000 from 3rd to 4th at the same throttle input.

This Cherokee I have is not right, I'm about convinced.

FlyinRyan 11-20-2011 10:26 AM

Re: Strange Shifting
 
Tune back to stock ASAP, and you may want to voice your issues to Diablosport...

RiverCityOffroad 11-20-2011 07:59 PM

I returned it to stock today. Surprisingly it does the same thing without the tuner installed.

I think it's just our Cherokee. I bought it used with 15k miles on it an it hasn't been right since day 1. Bad move on my part.

FlyinRyan 11-20-2011 08:19 PM

Re: Strange Shifting
 
The stock tune (TCM side) does alot of weird stuff with T/C lockup, it may be weird to you, but it is likely normal because of the way the shift/tc lockup schedule is...

This is why trans tuning is becoming more and more popular, because the factory tuning SUCKS.

RiverCityOffroad 11-20-2011 09:13 PM

Re: Strange Shifting
 
Quote:

Originally Posted by FlyinRyan (Post 518915)
The stock tune (TCM side) does alot of weird stuff with T/C lockup, it may be weird to you, but it is likely normal because of the way the shift/tc lockup schedule is...

This is why trans tuning is becoming more and more popular, because the factory tuning SUCKS.

I'm picking up what you're putting down here. The whole thing just seems to work against itself as a whole. Very strange little vehicle we've got there.

Thanks for your help!

Marcus

FlyinRyan 11-20-2011 09:39 PM

Re: Strange Shifting
 
Quote:

Originally Posted by MarcusRTJ (Post 518938)
I'm picking up what you're putting down here. The whole thing just seems to work against itself as a whole. Very strange little vehicle we've got there.

Thanks for your help!

Marcus

Check PMs...

jeepgcoman 11-20-2011 09:46 PM

Re: Strange Shifting
 
Like Ryan said, the TCM for the 545RFE's does weird things with the TC lock/unlock. On my 06 the RPM difference is ~75-150 RPM, with the lockup RPM being lower. Personally, I think they overuse the lockup feature, especially at lower speeds/RPM. At lower speeds it tends to lug the engine, and cause the MDS to kick off and lower the fuel economy slightly. I think their intent though is to aid the economy by reducing slipage. On mine it doesn't work, but then again, I am not completely stock anymore.

Ryan, have you gotten any control over the TC lockup with the CMR tunes?


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