I just bought a 2005 Ram 1500 3.7, with an Auto Tranny. I tow a small trailer. The truck does not have an option to leave it in 3rd gear when towing. It has 1st, 2nd and D on the column with a tow/haul button. The manual says to put it in Tow/haul mode when towing and the shift patterns will be changed. It also says it will STILL go into overdrive when Tow/haul is on. Does anyone know how to keep it in 3rd gear only for towing? is there and after market shifter that will allow this? or Can I have a switch wired in someplace to keep it in 3rd (to fool the computer)?

 

I've been wanting the same thing but there is nothing out there. The best out there is programers for $800.00 but you still will not be able to put the tranny in 3rd and stay there. My towing would be so much easier if I could select the gear I want when I want it. I like having an auto most of the time but when it comes to the hills I sure wish I could select the gear I want.

 

I think they have added this capability for the 06s. They are supposed to have the tow/haul mode and an OD off mode that takes out 4th and 5th gears.

 

I don't know why you'd want to downshift to third gear,cause it would be screaming with rpm's on the highway and sucking your gas. Right now your tow/haul button should keep you in 4th gear. Eliminating 5th gear should be enough.

 

When I'm towing my 8500lbs up hill and doing 50-60mph I want it in 3rd and not shift up to forth until I want it to. Tow a heavy load and you'll know.

 

i dont think there are 5 gears... i did some research on the trannsmission 45rfe has 5 gears TRUE but it is 2 second gears!! when you take off from the start you have a ~1.5 second gear, when you pass on the highway its like a ~ 1.67 second gear.. thats just wat i read though.

 

Jcarp if you knew you going to tow 8500lbs. why didn't you at least buy your truck with the 4.7 V8,I know the 3.7 is a good motor but if your going through mountains that will be a lot of strain on that motor over time. I have the hemi which is no problem in fourth gear.

 

You are right about the 45rfe. Most 5.7s come with the 545rfe which is a 5 speed. I'm not sure which he has with the 3.7

545rfe

1st 3:1
2nd 1.67:1
2nd prime 1.50:1
3rd 1:1
4th .75:1
5th .67:1

Even with the extra torque of the hemi there are conditions where it would be desirable to to lock it into a 1:1 ratio. Engine braking in the mountains comes to mind.

 

V-6 has the 45RFE automatic transmission. The 45RFE is a 4-speed automatic with an alternate second gear for the 4-2 kickdown when driving on the highway.

Gear ratios for the 45RFE are as follow:
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

2nd Prime is the alternate 2nd Gear for the 4-2 kickdown

The 287 and 345 Hemi V-8s are mated to the 5-45RFE Automatic transmission. The 5-45RFE is a 5-speed automatic with an alternate 2nd gear and 2 Overdrive gears.

Gear Ratios for the 5-45RFE are as follows:
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

2nd Prime is the alternate 2nd Gear for the 4-2 kickdown

 

Yea i wasnt sure but i knew there was a kickdown and some overdrives. thanks for cleearing it up in my eyes! ahhaahaaha i put it backwardss 1.5 and 1.67 or w/e lol