3.73 or 4.10 rear end gears

[RobertN]

Problem with bigs tires is the diameter chanches the overall/final sum of the gear ratio. Generally, 3.73 with 31's is like 4.11 with 33's, 4.56 with 35's etc.

The secondary issue, is bigger tires equal heavier rotating mass. That affects accelleration and felt "power". But, it also affects braking; it takes more to slow that heavier rotating mass.

going up a few inches in tire size needs bigger brakes about as bad as lower gears.

When you start changing tire sizes like that the gear ratio really suffers. The last set of gears I put into a GM were 4.88's to get the customer back into the desired RPM range. I think he was in the 35" range also. Go to Randy's ring and pinion and he has a configure program for gear ratio and engine rpm. Works slick and you can gain good insite by using it. CJ

 

[RobertN]

I see people doing this. Now way would I. He must have a 12-18" drop hitch. I see these guys doing this, and have extra braces from the hitch to the frame. Would really hate to be in emergency situation or high wind in a rig like that.

I really like the looks of a lifted truck. But to lift that much, big tires, and tow... No.

My neighbor has a 2010 2500 HD Hemi with a 9" lift and 35's...The 4:56's are certainly put to good use in his. He pulls a TT similar to mine and it does that well.

 

[DeereMann]

Yeah, I agree that 3.73 is the "medium" capability gear ratio for final drive axles. If you pull often, large loads, hilly terrain, then go with 4.10 ratio. If you don't pull much, live in flat country, go with 3.54/3.55.

Here in upper midwest, I tow some, with medium loads, in partial hills, so 3.73's suit me just fine.

 

[CJONE]

Problem with bigs tires is the diameter chanches the overall/final sum of the gear ratio. Generally, 3.73 with 31's is like 4.11 with 33's, 4.56 with 35's etc.

The secondary issue, is bigger tires equal heavier rotating mass. That affects accelleration and felt "power". But, it also affects braking; it takes more to slow that heavier rotating mass.

going up a few inches in tire size needs bigger brakes about as bad as lower gears.

That's why I mentioned the program from Randy's it is a great tool. I agree 100% on the brakes some truck have undersized brakes to begin with like the GM's and really feel the bigger tires. So care must be taken. As far as towing heavy with lifted trucks, IMHO it is not a good idea for a bunch of reasons like was stated. CJ

 

[hawkeye08]

My 2011 GMC 2500 CCSB 4WD 6.0/6sp has 3.73 and I wish I had bought the 4.10 gears instead. Empty, I don't mind, but when towing my 7000lb travel trailer, I would like to have ~200 rpms more than I have. It would have a bit more power and not have to downshift with small hills. With the double overdrive (5th and 6th are both over drive), you have plenty of gears to drive 70-80 mph if you want and still have reasonable rpms. Also note, my 2011 truck came with 18" tires, my Dad's 2008 came with 16" tires. Mine are noticeable bigger, he has 3.73 and likes it.

My brother got a 2013 GMC 2500 CCSB 4WD 6.0/6sp with 4.10 (on my advice) and absolutely loves it. He lives near Denver and has no problem going as fast as he wants on the open roads and enjoys pulling his travel trailer (I think around 8000lbs).

 

[JerryK]

Geez, my little six cyl inline 359ci turbo H.O. Cummins six speed seems to work just fine with the Dana 80 3.73 rear end... even with a couple size larger tires than stock.... [ ] [ sorry, I couldn't resist ]

 

[Raw Dodge]

Geez, my little six cyl inline 359ci turbo H.O. Cummins six speed seems to work just fine with the Dana 80 3.73 rear end... even with a couple size larger tires than stock.... [ ] [ sorry, I couldn't resist ]

How did you get 3.73 in an 02? It wasn't offered until 03.You had a 3.54 or 4.10 option that's it.....Those trucks should have had 3.42 option but they didn't offer that either...6 th is pretty low on the 5/6 speed trucks...

 

[timswi]

I see people doing this. Now way would I. He must have a 12-18" drop hitch. I see these guys doing this, and have extra braces from the hitch to the frame. Would really hate to be in emergency situation or high wind in a rig like that.

I really like the looks of a lifted truck. But to lift that much, big tires, and tow... No.

I know what you're saying but the truck pulls car trailers and TT's perfectly, no sway at all even in wind...I followed him for 2 hours back from camp when we pulled out a couple of weeks ago...Stable as can be.

 

[Raw Dodge]

If you have any way of getting 4.10s ,that's what you want.Dont listen to the people saying it will get bad mpg on the highway..that only applies to the older (lighter)trucks with 4 speed autos and smaller factory tires. Starting in 2011 the GM HD trucks gained 400 lbs over the identical 2010 models...they also got larger tires and much larger brakes..the larger tires bring the 4.10- down to about a 3.90 ratio as compared to the older trucks ,the added weight combined makes the trucks really need those 4.10s,to perform well towing,and even empty,that's why the tow rating is so much higher,th 3.73s make the truck work harder in every gear.The 6speed auto with double OD negates any mpg loses,it is able to stay in6th on the highway,with 3.73 the truck will lug and hunt between 5th and 6th constantly on the slightest grade or with the slightest headwind...what's going out get better mpg a 4.10 truck at 2000rpm in 6th on the highway at 70,or a 3.73 truck running 2400 in 5 th half the time,then lugging in 6th the other half because it can't pull 6 th except on downhills and dead flats

 

[JerryK]

Pardon wa, I got caught up in the moment. My 2002 [ old body style 2002 BR body style, not the new one they started selling in 02 ], has a 3.55 Dana 80 posi rear.... All they offered in the BR model that year was the 3.55 or the 4.10. My snowplow packaged, special ordered, non-carpeted truck still does not even snort hard pulling 8000#...... As to 3.54 or 3.55 ... you got me there. But I still have a pristine 2002 2500/3500 Dodge truck brocure... and it says 3.55/4.10. But, if you go to DieselRam.com, I list my rear as 3.54....