I have an 02' ram 4x4 quad cab w/4.7 motor & 20" hemi wheels, want to know if a gear swap would help with towing a travel trailer. If so what gears should I go with

 

Most definitely, do you know what gears you have now? 3.55 or 3.92? Also, has the transmission ever been updated from the 45rfe to the 545rfe?

 

I have 3.55 and no the trans has not been upgraded

 

What size tires you running?

 

275/65/20

 

4.10s would be your best bet, but if you have the transmission software updated to make your 45rfe into a 545rfe you'd have essentially two over-drive gears and with such a step up to 4.56 gears would be the way to go.

Without the extra over-drive gear 4.56s will give you great power for towing/hauling, but you'd lose a bit of fuel economy on the highway...

 

My rig is in the shop right now getting 4.56s and a Detroit TruTrac put in. Based on Hammer's recommendation to me, I'd go with 4.56s since you're running 34s.

 

Just out of curiosity, how would updating the transmission software add another overdrive?

 

• 45RFE Gear Ratios:
  • 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 only:
  • 5th 0.67:1

 

I don't know how you'd have to go about updating your 45RFE to a 545RFE but with my Durango I had to replace the TCM with one from an 02 Cherokee as they had the 545RFE programming in their TCMs. Basically the 45RFE has two sets of planetary gears in it and it only uses one. By updating the software within the TCM you are essentially telling the trans to utilize the second set of planetary gears, thus giving you a second overdrive. I guess technically with the 45RFE you have 5 forward gears (Including 2nd prime) and 6 (also including 2nd prime). If you didn't know the 2nd prime just uses a higher 2nd gear ratio for passing and the likes.

And for your gearz situation, if you don'tplan on getting anything bigger than 35's I would get 4.1s, anything bigger than 4.56 gears. I'm currently debating a 4.1 install on my 4x4 to run 33s, but the parts cost is ridiculous just because I have a 4x4.