big blue. I appreciate your heolp, I really do, but I have said at least 5 times or more, regardless of what mode I'm in, tow, or "manual" for lack of a better wore, it will NOT lock out of 6 gear, period. Now with "manual" mode in 5th it should NOT go in 6th, thats what the problem is, it DOES go in 6. It should NOT try to haul that weight in 6th, not at 65 MPH with 3.56 gears. My 6.4 Diesel would but this Ram is over 250 lbs of torque less. I don't expect it it but I DO expect it to stay in 5th in tow mode OR manual mode. Chrysler agrees, now lets see if they can fix it. Its theirs, and their nickle. I dont know wether it the tranny, torque converter or wiper blades it WILL burn the tranny up if it continues. I hauled boat this A.M. with new tires, (i needed anyhow) Have also put on cold air box that gives it a tad more H.P., I guess. It seems a little better BUT will STILL try to run in 6th at 65 MPH, 1600 RPM's. Aint gonna happen unless they put a CUMMINS in it, I doubt they will.

 

rpms moving with tranny shifting, for miles at a time? Now I know why I was a Ford man for so many years.!!

 

you mean to tell me when it "shifts" or don't shift, and changes RPM 2100 to 1600 back and forth, back and forth that it really isnt shifting??? Thats like a Dr telling your loved ones you really didn't just die, it just seems like it!! LOL Trust me, I have over 5,000,000 miles experience driving tractor trailer.......its shifting! Do you by any chance work for Chrysler????

 

Last time. As I have said MANY times. Towing , in Manual mode,5th gear. 65 MPH. Flat terrain, hey its florida! I 95 doesnt change 2feet from Daytona to Ft. Pierce! Even locked in 5th the Tranny DOES shift into 6th. With 3.56 gears, 20" tires 65 MPH is 1600 rpm......in 6th. THAT is what it shifts into, even locked in 5th. That is what is wrong.

 

You are right! there is now way you should be seeing 1600 RPM with your setup if you lock out 6th gear. At 65 MPH this is what you should see

6th = 1590 RPM
5th = 1780 RPM
4th = 2370 RPM

 

The RPMs will definitely change as the torque converter locks and unlocks. That's the nature of an automatic transmission.

I'm not saying for sure that your trans is not going into 6th, but there are a lot of things that may make you think it is when it actually isn't. The only way for you to know for sure what gear you're in at any particular time is by checking the RPMs versus actual speed with the TC locked. And you can only do that at steady-state conditions with a light load on the engine (or else TC might not be locked up).

Rob

 

Actually, the rear axle ratio does make a difference. The lower axle ratios will make it less prone to transmission shifting.

If you look around the Ford and GM discussion sites, you'll see similiar comments regarding excessive shifting. The problem is that now there are more gears available, the engine management systems have a broader opportunity to select a gear range up or down that optimizes engine performance for acceleration and economy. Since the system is designed to be sensitive to engine load, this usually means that in what the driver perceives to be "normal" driving, there may be a lot of 5-6, 6-5 shifts. And that's the outcome of more sophisticated engine management systems.

This wasn't a big complaint with most light duty pickups in past years because the five or four speed transmissions had to stay in gear longer regardless of engine load. When carrying or pulling heavy loads, the Tow/Haul feature is suppose to be used to reduce excessive shifting and possible transmission overheating (See page 404 of the Ram Operation Manual).

Big Blue stated stated it very well. The selection of any gear in manual mode does not lock the transmission into the gear selected like a manual transmission, but limits the highest available gear to the one selected.

Keep in mind that the only way to access all six gears on a 645RFE is to enter the ERS mode. You will not have six sequential gears when in the Drive mode. (Look at page 397 in the Ram Operation Manual.)

"When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading conditions,
in hilly terrain, traveling into strong head winds, or
while towing heavy trailers), use the Electronic Range
Select (ERS) feature (refer to “Electronic Range Select
(ERS)” in this section) to select a lower gear range. Under
these conditions, using a lower gear range will improve
performance and extend transmission life by reducing

excessive shifting and heat buildup."
- page 393 of the 2012 Ram Operation Manual


NOTE: Don't get confused with the transmission and ERS description found in the Ram Operation Manual for the Ram 2500. That transmission is a 66RFE and operates differently.

Based on your last response I suspect you may either be trying to drive the vehicle in the ERS mode for normal driving, or you're not realizing the actual load being placed on the engine. If you see a gear number displayed in the EVIC while your driving, you are in the ERS mode.

But now I'm thinking you have different expectations based on past experience.

Watch the datagraph in the EVIC as your driving (this is the white horizontal bar that moves left or right indicating the vehicle miles per gallon use rate). At a true constant load the datagraph will indicate a steady reading, i.e.: 20 miles per gallon. If you see the datagraph line moving to the left (indicating a lower MPG), you're either experiencing an increased load or accelerating. You may not sense this as your driving since the vehicle insulates the driver from road conditions very well. This may cause the transmission to shift into a lower gear. This is more pronounced on new vehicles that have not been broken in yet.

Best regards,
Dusty

 

1600 RPM, 65 MPH, 20"wheels = 6th gear.

 

Oh, the 04 ford would stay in 4th (5 speed tranny) 350 miles to the keys, never shift, BUT 3000 RPM, 70 MPH.

 

thank you Pedro!!! Dusty, just how do you suggest I select a "lower gear range"??? in tow mode at 65 it DOES go to 6th gear. In manual mode it DOES go in 6th gear. So please explain how I "select" a lower gear range? As i said 3.56 gears, 20"wheels, 1600 RPMS = 6th. gear. If you can tell me how I can select a "lower gear range" problem will be solved.