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Old 11-12-2011, 12:00 AM
hpc3 hpc3 is offline
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Location: Piedmont of the Carolinas
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Vehicle: 2010 Ram 1500 Laramie Crew 4x4
Trim Level: Laramie
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Default I don't believe this is the case with the shift patterns on the '10 545RFEs...

Quote:
Originally Posted by snrusnak View Post
The mpg is not any better because it is literally the exact same physical transmission. The rams before 2012 have a 545rfe "5 speed" transmission, but it actually has 6 forward gears. One of the gears is in between 2nd and 3rd and is called 2nd prime. It is mainly used for downshifting only. When you select tow/haul mode the gear pattern gets changed to eliminate the 2nd overdrive gear, and make the 2nd prime the 3rd gear, 3rd becomes 4th, 4th becomes 5th. The 2012 "6 speed" is the same it just has different programming so it always uses all six forward gears. 2nd and 2nd prime are so close in ratio that mpg is unaffected. IMO they did this to be able to market their truck as a "6 speed". Only other change was the torque converter. The predecessor to the 545rfe in chryslers was the 45rfe(still again the same physical transmission, just programming differences).

45rfe:
1st 3.00:1
2nd 1.67:1
2nd Prime 1.50:1
3rd 1.00:1
4th 0.75:1
Reverse 3.00:1

545rfe:
1st 3.00:1
2nd 1.67:1
2nd Prime 1.50:1
3rd 1.00:1
4th 0.75:1
5th 0.67:1
Reverse 3.00:1

545rfe in tow/haul mode:
1st 3.00:1
2nd 1.67:1
3rd 1.50:1
4th 1.00:1
5th 0.75:1
Reverse 3.00:1

65rfe for 2012 rams:
1st 3.00:1
2nd 1.67:1
3rd 1.50:1
4th 1.00:1
5th 0.75:1
6th 0.67:1
Reverse 3.00:1
Although the gear ratios are the same there is no difference in normal driving between tow/haul and normal operation on mine. The trans in 2WD uses the following pattern(that I really hate with a passion):

1st
2nd prime
4th
5th
lockup

3rd is never selected, nor is 'true' 2nd unless it is a kick-down in 4wd mode. I've watched the schedules off and on now with a diag tool and can't understand why Chrysler would do this. I would be much happier if my truck used 1st, 'true' 2nd, 3rd, 4th and then 5th ... this should be possible with the gear sets... correct me if I'm wrong.

I'd buy a tuner if I could remap the gear change schedules. From what I've read the Supertuner one only allows torque management adjustments and shift timing on the stock trans programming, no gear selection changes. This is the one thing on my truck that really bothers me after a 1.5yrs of troublefree ownership. The 2ndP to 4th gear lag for town driving is awful, kick down response as well. If Chrysler would close the gaps in the first three 'true' gears this truck would be about perfect. I can tell you on the '12s(which I have not driven) if they are skipping gears for mileage or emissions reasons it will be no better than what I have today. The trans is *never* in the right gear for towing with the stock schedule. I have to manually shift or exaggerate the accel pedal to get it to respond.

Looking for help. Any tuning feedback appreciated.
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