lowering gear ratio

[C-Moore502]

So I have a 84 K20 with the 6.2 and my truck has the 3.73 gear ratio. I think I would like to lower it to 4.10. I'm still a little new to 4x4's so any input would be greatly appreciated. If I do change the gearing which parts besides the axles and transfer case would need to be re-geared as well?

[Da67goatman]

I think you should be fine unless your running some 35" or larger tires.

[C-Moore502]

Well I was considering getting some 35's and a 6" lift kit but I'm still trying to figure it all out.

[motion427]

Just need to regear the differentials,not the transfer case.

[Irish_Alley]

I think you will be good with 3.73. I'm running 4.10 with a sm465 and 38s. So it has a 1.1 transmission ratio and at 50 she's at 2k. That's high in my opinion I would like to step up once I get a chance

[C-Moore502]

Alrighty then, well thanks for saving me some time and money then guys

[dcayers]

You can expect to lose some fuel mileage until you put the bigger tires on it. We just pull the 4.10's out of the 84 6.2 and put 3.42 in and helped the fuel mileage tremendously. Diesel's like lower rpm range.

[1979C20]

I think you will be good with 3.73. I'm running 4.10 with a sm465 and 38s. So it has a 1.1 transmission ratio and at 50 she's at 2k. That's high in my opinion I would like to step up once I get a chance

irish, my trucks got the sm465, 4.10's or 4.11's and 30" tires and it runs 2k rpms at 45! 50 is closer to 2200rpms.

[Irish_Alley]

Lol thought I had it bad

I made a little boo boo ment 55 was 50 with the 4.56

[4x4x4x]

So I have a 84 K20 with the 6.2 and my truck has the 3.73 gear ratio. I think I would like to lower it to 4.10. I'm still a little new to 4x4's so any input would be greatly appreciated. If I do change the gearing which parts besides the axles and transfer case would need to be re-geared as well?

we have a 1985 k10 with a 6.5 turbo diesel and 700r4. it had 373's, when we replaced the tires with 33/1250r15 goodyear mtr's the gearing was too high, it was hard to pull hills (shifting between 3rd and 4th gear) and the truck lacked power. we switched out the front and rear differential gears (and added electric lockers) and now the truck runs great. i checked the speedo with a gps and it reflects the correct speed, and the engine rpm is back in the stock range. the last time i checked mpg is was 22mpg hwy (driving easy)

randy's ring & pinion site has rpm calculators that will allow you to compair engine rpm/tire size/differential gear ratio.

http://www.ringpinion.com/Calc_RPM.aspx
alec

[bake74]

So I have a 84 K20 with the 6.2 and my truck has the 3.73 gear ratio. I think I would like to lower it to 4.10. I'm still a little new to 4x4's so any input would be greatly appreciated. If I do change the gearing which parts besides the axles and transfer case would need to be re-geared as well?

we have a 1985 k10 with a 6.5 turbo diesel and 700r4. it had 373's, when we replaced the tires with 33/1250r15 goodyear mtr's the gearing was too high, it was hard to pull hills (shifting between 3rd and 4th gear) and the truck lacked power. we switched out the front and rear differential gears (and added electric lockers) and now the truck runs great. i checked the speedo with a gps and it reflects the correct speed, and the engine rpm is back in the stock range. the last time i checked mpg is was 22mpg hwy (driving easy)

randy's ring & pinion site has rpm calculators that will allow you to compair engine rpm/tire size/differential gear ratio.

http://www.ringpinion.com/Calc_RPM.aspx
alec

      Which gears did you switch too ?  4.11 s.

[4x4x4x]

So I have a 84 K20 with the 6.2 and my truck has the 3.73 gear ratio. I think I would like to lower it to 4.10. I'm still a little new to 4x4's so any input would be greatly appreciated. If I do change the gearing which parts besides the axles and transfer case would need to be re-geared as well?

      Which gears did you switch too ?  4.11 s.

we went with 411's, also added auburn gear ected limited slip/electic lockers and rear disk brakes. just had marine injectors installed, big difference in power.

[beastie_3]

im running 33 tires and 3.73 gears and I dont have a problem with it.

[1979C20]

My mom has 3.73s and 35's on her 03 avalanche andbits doin a bit of a number on her engine

[beastie_3]

key word: 2003

Our trucks can handle more than a newer IFS truck