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-   -   07 tranny issue, I think! (http://www.jeepgarage.org/f5/07-tranny-issue-i-think-18080.html)

JCFiredog 01-28-2011 11:30 PM

07 tranny issue, I think!
 
OK I am new, I have not even owned a car of my own in 12 years. (Company Cars!) Bought a used 07 WK Limited with the hemi and the QDII. I really love it other than one issue. While driving I noticed that at times I could drive different highway speeds at different RPM. So I started messing around. I accelerated to the speed limit and put the cruise on. If I push the accelerator down and accelerate 2-3 mph then let off the gas it seems to allow the torque converter to lock up. The engine will drop 300 rpm at 60-65 and even more at 79. :confused: I took it to the stealership I bought it from (had 46k) they ran codes and said it did not need any updates and there were no codes so no issues... I am calling BS!!! The transmission guy seemed to not care that it was doing this. He even made it do it while he was driving.

Am I looking at an issue in the future? I do feel that after he was in the computer it seems to shift more noticeably. Still there are times when it does this non lock up thing. I am convinced it will be an issue and the dealer is not interested in a fix.

Anyone? All I can think of is the shift schedule is wacked.

Thanks!!!

jeepgcoman 01-29-2011 03:31 PM

Re: 07 tranny issue, I think!
 
Sounds normal to me. What you're feeling is indeed the converter lock kicking in and out. When it comes on MDS must be off and the engine RPM drops to match (within 5-10 RPM) the torque converter speed. I have a screen on my DashHawk set up to monitor this activity. Also, when the MDS is active the converter is not locked up, and the engine RPM is higher than the converter speed.

One thing that is crappy, IMO, is the stock shift schedule on the 545RFE tranny. You can resolve this by purchasing an Superchips tuner and their Advanced Trans. Tuning App. With it you can modify you upshift/downshift schedules any way you want. This makes the transmission almost descent. Wish they had put the NAG1 in it, like the 3.7 and 6.1. The 4.7 and 5.7's get stuck with the inferior one. I have the NAG1 in my Hemi LX, and, IMO, it's a way better setup. With a tuner you can make it into a true autostick too.

vman_86 01-29-2011 03:57 PM

Re: 07 tranny issue, I think!
 
there really is nothing worse than a tranny that makes funny noises...

or better yet, something that starts making funny noises and then you realize it's a tranny ;)

JeepCoop 01-29-2011 05:14 PM

Quote:

Originally Posted by vman_86 (Post 344097)
there really is nothing worse than a tranny that makes funny noises...

Or better yet, something that starts making funny noises and then you realize it's a tranny ;)

lol!!!!!

vman_86 01-29-2011 05:21 PM

Re: 07 tranny issue, I think!
 
haha, i was hoping someone would read that and find it funny

JCFiredog 01-29-2011 08:40 PM

Re: 07 tranny issue, I think!
 
Quote:

Originally Posted by jeepgcoman (Post 344091)
Sounds normal to me. What you're feeling is indeed the converter lock kicking in and out. When it comes on MDS must be off and the engine RPM drops to match (within 5-10 RPM) the torque converter speed. I have a screen on my DashHawk set up to monitor this activity. Also, when the MDS is active the converter is not locked up, and the engine RPM is higher than the converter speed.

One thing that is crappy, IMO, is the stock shift schedule on the 545RFE tranny. You can resolve this by purchasing an Superchips tuner and their Advanced Trans. Tuning App. With it you can modify you upshift/downshift schedules any way you want. This makes the transmission almost descent. Wish they had put the NAG1 in it, like the 3.7 and 6.1. The 4.7 and 5.7's get stuck with the inferior one. I have the NAG1 in my Hemi LX, and, IMO, it's a way better setup. With a tuner you can make it into a true autostick too.

So if I am reading this right it would be normal to be driving down a flat road and it not lock in? I mean I was driving in OK. Yea one of the flattest states, very little grade and when I get up to speed it never locks in. I will be driving along at 2500 rpm at 70 MPH. This is with or without the cruise on. Now if I am cruising along and I push on the gas and it accelerates a couple miles an hour then just let off the RPM will drop to 2000 to 2100 and stay there. I can feel the MDS at times but it only moves 100 or so. This seems weird. I would think it would automatically lock up by the time I was cruising down the road at 70+ mph.. Oh well I guess I can keep forcing it to lock in. It actually makes quite a bit of difference in fuel mileage.

So this Superchips with the tranny tuner how hard is it to use? I am plenty mechanically inclined and good with my hands but I am worried about making changes and screwing it up totally!! I bet if it possibly to screw it up I can do it!!! Does it come with some sort of starting point? I am more fearful of making changes and burning something up or worse!!! :eek: Thanks!!

jeepgcoman 01-29-2011 10:50 PM

Re: 07 tranny issue, I think!
 
The way you described it above is NOT the way it should work. You should not have to force the converter to lock up. It should happen automatically, and you may feel a slight bump, along with the RPM drop. (IMO, to get an accurate assessment you should have some way of monitoring Turbine Speed, Engine RPM, Engine Load, Throttle Position and Vacuum....i.e DashHawk) For example, if I am cruising along with the cruise on and the MDS active, it will lock up within 1-2 seconds after the MDS kicks off. Sometimes it happens almost simultaneously. I can feel the noticeable RPM drop and the bump, and also note it on the DashHawk. Throttle position, engine load and other engine parameters will also impact the feel. Have you tried switching the Tow/Haul button on? This will lock the converter and limit the gear to 4th with no MDS? Does that work properly?

On mine with stock settings, it upshifts from 4 to 5 right at 63 mph. This sucks, because most of my highway driving is around 65 mph. In my operating environment, which is mostly rolling hills at 2500-4000 ft. elevation, the engine RPM is too low to support 5th and still have MDS available. When I run the SC with the ATT App., I set the 4-5 upshift to ~67 mph. This allows me to be in 4th (with much more MDS) at my normal cruising speed and if I want 5th (more level terrain) I can just tweak the throttle a little and get it to upshift and still get the MDS to come on. If I want to go back to 4th, I just backshift it to 4th and then back to D and I get my MDS again.

As far as the SC AAT App. goes, it is very easy to setup. If you don't want to mess with it too much at first, just use their canned setup. It's not bad. What I did was make notes (as above) of where I had grief with the shiftpoints....4-5 speed ~63 mph (highway), 3-4 speed ~33 mph (around town), 1-2 speed ~13 mph (school zones), etc., and then set them where I wanted them (all higher) to shift. I am on my 3rd adjustment and feel it is about right now. The SC folks purposely don't give you a lot of guidance, as it is almost strictly driver preference. There are also plenty of sample shift schedules on these and the SC related forums. Also, don't worry, you won't mess anything up....I think you'd really have to work hard to do that. I also added the Sonnax Line Pressure Booster to mine. This helped the shift quality quite a bit.

lll2for3lll 01-29-2011 11:49 PM

Re: 07 tranny issue, I think!
 
Ok so it's starting to look like slightly hard downshifting is normal.

JCFiredog 01-30-2011 12:50 AM

Re: 07 tranny issue, I think!
 
OK so I should get a Dash Hawk and a Programer. Looks like I have some research to do, gotta figure out where to buy and how to use em!!! Hey my 07 does not have the MDS light like my wifes Crew Cab Dodge Ram Hemi does, so how do you know for sure it is in MDS mode? I can feel that little change when it activates sometimes. But at times I wish we could see something tell me it was on. Does the Dash Hawk show MDS activation? Thanks for all your help. By the way with the converter locked inand cruise on at 70 I pulled 20.2 MPG, per evic.

JeepCoop 01-30-2011 01:27 AM

Quote:

Originally Posted by JCFiredog (Post 344322)
OK so I should get a Dash Hawk and a Programer. Looks like I have some research to do, gotta figure out where to buy and how to use em!!! Hey my 07 does not have the MDS light like my wifes Crew Cab Dodge Ram Hemi does, so how do you know for sure it is in MDS mode? I can feel that little change when it activates sometimes. But at times I wish we could see something tell me it was on. Does the Dash Hawk show MDS activation? Thanks for all your help. By the way with the converter locked inand cruise on at 70 I pulled 20.2 MPG, per evic.

I could be wrong, but I think the MDS came out on the 08 Grand Cherokees. I don't think I have MDS on my 07 Hemi, but again I could be wrong lol

jeepgcoman 01-30-2011 09:20 PM

Re: 07 tranny issue, I think!
 
MDS is on all 5.7 Hemi's, except some of the earlier Rams. All of the 5.7 Hemi WK's have it. Beginning with the 08's they've added an "econo" light that shows activation. The DashHawk does have a PID for the MDS activation but, IMO, a light is the better way to go. I have one on mine. Where mine is mounted is much easier to see and you don't have to take your eye off the road to see it. Here's a thread that tells you almost anything you may want to know about the MDS. How to install the light is referenced in Post No. 14 of the thread: http://jeepgarage.org/showthread.php?t=17136 If you have any questions about it, I'd be happy to attempt to answer them for you.

lll2for3lll 01-30-2011 10:06 PM

Re: 07 tranny issue, I think!
 
MDS has been around for a while. It's on my late uncles mid 2000 RAM.


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