For gods sake if your buddy has a 2012 then get in and give it a try....SOLVED.

 

here is how it works...your transmission is the 545RFE which is a 5 speed with a secondary second gear. So in normal driving you get regular second gear and 5th gear which is the overdrive. Now when you use tow haul it basically removes the 5th gear overdrive and adds the secondary second gear so you still have 5 forward gears. Plus when you push the tow haul button it will read 5 in the evic display for those 5 gears. Now your buddy who has the 2012 truck has the 65RFE trans which is the exact same as ours except for the software which allows him to access both of the second gears while in ERS mode. So if he enables ERS on his truck and it says 6 in his evic then he still has access to his high gear. Same goes for tow haul on his truck. If he presses his tow haul button and his evic says 6 then he has access to his high gear also. So get in his truck and give it a try. That is the best I can explain.

 

If you want to go through your 6 gears like the 2012, do a test from take off. Use your slap shift starting in 1st, then 2, 3, 4, 5 then to get to the 6th gear just hold your stick to the right to bring it back to auto and that last gear will engage. One way to look at it.

 

I'm just looking to see if more then the 2nd secondary gear program was changed. I knew that in regular drive and then in ERS was not the same gear ratio. I should have looked in the owners manual to start with. The discussion,question started because in my truck in 5th ERS there is obviously a difference in gear ratio and RPM turned at 60 mph over regular drive,5th gear. My friend say not so in his 2012. In my year model truck 5th more or less is deleted in ERS. Because in ERS top gear is 4th direct. It may say 5th. Thats the question I was asking more or less. The answer was in print in the owners manual. Is 2012 the same deal or not?

 

no change in rpm at interstate speeds whether mine is in drive or
6. Call it what you want

 

Ok. Mine has a big difference in drive or select fifth. If it operates like the owner manual states. There has to be a notable difference as mine is not Fifth OD if select shift 5. Its been changed to direct(No O/D gear) 4th. Tow/haul also does away with o/d 5th. It also changes it to direct 4th as the highest gear.

 

Dumb question, I need to research this but does the 2012 now have a true 6 speed trans. Lower 1st and closer gearing would certainly help, I thought we had to wait on this 8 speed they are starting to use in the cars.

 

Same as previous year 5 speed with a somewhat different programing that allows more usage of 2nd gear that is split. Its called a six speed for 2012. But really the same as the five speed in 2009 trough 2010. I believe gear ratios are the same as previous years. MARKETING. the NEW 6 speed. Yea right. LOL

 

The 545RFE (1999-2011) has the following gear ratios:

• 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
• Rev = 3.00:1

The 645RFE (2012) has the following gear ratios:

• 1st = 3.00:1
• 2nd = 1.67:1
• 3rd = 1.50:1
• 4th = 1.00:1
• 5th = 0.75:1
• 6th = 0.67:1
• Rev = 3.00:1

Note that 1:1 direct drive is 3rd gear on 545RFEs, and 4th gear on 645RFEs. Overdrive begins at 4th gear on 545RFEs, and 5th gear on 645RFEs. The 545RFE and 645RFE use the same transmission case and internal drive archetecture with a different torque converter for 645RFE.

The major difference between the 545RFE and 645RFE is the latter uses all six forward gears sequentially in the Electronic Range Select mode, but uses the 545RFE shift sequence in the normal drive mode. When in the normal mode, the 645RFE operates like a 545FRE and never uses 2nd and 3rd in succession (3rd becomes 2nd prime).

In both 545RFE and 654RFE transmissions, selecting Tow/Haul Mode shuts off MDS, prevents torque converter lock-up in 4th & 5th gears (545RFE) or 5th & 6th gear (645RFE), and utilizes a prolonged shift schedule in all forward gears.

Regards,
Dusty
2010 Ram Big Horn 1500 Quad Cab 2WD, 5.7 Hemi, 545RFE, 3.92 LSD, dual exhaust, 20” wheels

 

Good job explaining the difference, accurate and easy to understand. The new torque converter is supposed to help a little with fuel mileage.