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4.10 or 3.55 gears

17K views 13 replies 10 participants last post by  bootstrap 
#1 ·
I have 4.10s in my truck now but the rear is starting to take a and with my stack and the gearing going down the highway is horrible i was gonna switch to 3.55s but i go to the pulls with my truck in the summer and would hate to lose the low end of the 4.10 any suggestions??
 
#2 ·
You can't have your cake and eat it too. A 3.73 would give you a compromise between the two, but might not drop your RPMs enough on the highway to be worth the loss of lower gears for pulling.

Figure out whether pulling or highway driving is more important and go from there.
 
#3 ·
I'm actually going to put a set of 225/75r16 tires on my truck. I have 3.55 gears and calculated that going to this size from a 215/85r16 would simulate somewhere around a 3.80 rear end. I tow an enclosed trailer most of the time, but don't really need to full grunt of 4.10. I think it will bump me up another 100 or 200 rpm at most speeds.

You could do the opposite and put a little taller tire to drop your rpm a little and keep a smaller set of tires just for pulling with. An inch different in height is a pretty big change in rpm without adding a ton of weight. Luckily bigger tires don't hurt us as much as gas trucks, so don't drive with your foot on the floor and mpg shouldn't drop.
 
#4 ·
I had 4:10's in a 97 dually I didnt like them they were too low. I swaped to 3:55 and never looked back. Worked so much better on the highway. I never did any sled pulling though but you would think you would want the wheel speed from the 3:55. Its not like you are pulling on asphalt.
 
#5 ·
I never thought i would say this buy I like the 4:10's on my 95. I just got done driving it 2000 miles across country (Northern Washington to Southern New Mexico) and it was not to bad. 2300 rpm @ 75 with a 265-75-16 tire and still avg 18.2 mpg. Although I dont have a stacks which I bet are really loud. When I run these tires out I will put a little taller tire on there though.
 
#6 ·
Yeah I'm not exactly what rpms I'm at but it sucks crusing at 75 80 and the stack drones and I know everyone's gonna say get rid of the stack. But yeah I'm think 3.55s or maybe 3.73s now I just want somthing that cruises the least bit better on the highway
 
#7 ·
I say to go with BOTH gear ratios. You would spend at least $500 just for a carrier and the ring and pinion. Instead just find a used axle (probably $500-$800) with the correct ratio and have 2 axles. One for pulling and one for normal driving. A couple hours or so would swap them out for the occasion you want.
 
#10 ·
One Step Further

With duallys, 4:10's and 4WD I have the maximum drag on fuel mileage.
This is a work truck though not a boulevard cruiser.
Thinking larger diameter tires and single rear wheels before going for the taller gears.
Guess it depends upon the motors torque peak rpm and where we run mostly.
Am i blowing smoke here or what?
 
#12 ·
it is a lot easier to swap a set of tires than it is a rear end!
have a small diameter, deep lug, traction set of tires for pulling sitting in the back yard.

put tall, skinny, highway tred tires on (for the least rolling resistance) to lower the cruising rpms
 
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#13 ·
Rickson Wheels

Think I am going with the Rickson dual to single conversions.
Put in an order today, out about 10 weeks.
19.5" truck tires to get about the same carrying capacity as the dual wheels.
Different diameter/carrying capacity tires allow a change in overall ratios, not sure what tires, just know they are too expensive, gack.....
Wish there was a better way, but this might do it.
 
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