Re-gearing for Km2s : Suggestions Wanted

[99runnerwa]

When i re-geared to the 4.88's i saw a huge difference in acceleration (all relative, it is still a 4runner). My mileage around town went from about 14 to around 16-17. at 70 mph i am running just under 2500 rpm with my 33's. My overall gear ratio including the tires is a little bit lower than stock but it helps out with the extra weight i am carrying. if you do use it as a dd and see any highway use i would caution against anything lower than the 4.88 or you will be seeing some high rpm. I went with the Drivetrain Specialists East Coast Gear Supply with the ARB lockers installed. It is pricey but they ship it fully assembled and they warranty it. This saved me a lot of time and head ache and worry down the road. there are a few other places that do the same thing but that is the one i ended up going with.

 

[mory]

My 98 sr-5 4x4 with stock 4:10 with 305-65-17 with procomp 1089 wheel 2.5 lift fronth and 3.5 lift rear in city i get 16-17 mpg and in highway get about 21-22 mpg and going 70mph at 2,200RPM, the only drawback is going up high hill lost lot power, still debating about 4:88, i get almost gas mileage my bother 97stock limited 4x4.

 

[FrankM23]

To brian

4.88s for a daily driver.
5.29s for an off road rig.

That's assuming you're auto tranny. Like YotaZach85 said, don't bother with 4.56s. I completely agree that they will not be worth the money. If you're a manual, 4.56s will be good though.

Brian why does it make a difference if its a 5 speed as compared to an automatic, both being with 4.56's. Ive got the stock 3.91 gears with a 5speed but want to run either 265/75/16 or 255/85/16. And have been searching this thread for ages! No armor though. And its definitely DD wheeling maybe once a month. Only for now! So curious, whats the difference

 

[brian2sun]

The 5 speed's 5th gear is lower than the auto's O/D (4th gear). Your rpms will be a few hundred higher at highway speeds than an auto's would be if you both had the same diff ratios. So 4.88s and 5.29s are a little on the low side (high rpms) for a 5 speed/33s DD with little or no armor/extra weight.

Even with 3.91s, since you have a 5 spd, I probably wouldn't bother regearing just for 265/75s. Your 3.91s + 5 spd = about the same power as an auto with 4.30s. I ran 265s with my auto and 4.10s for years and always felt like it had good power so it's just not worth the $$ IMO unless you go to 33s.

If you want 255/85s or any other 33s, I suggest 4.56s because your is a 5 spd DD without extra weight. 4.88s would be best if your going to add 500+ lbs. or ever run 35s. 5.29s if you're gonna run 35s and have armor.

Note: This is all assuming you have the 3.4 motor. If you have the 2.7, there are better people to ask on here who have that motor.

 

[FrankM23]

The 5 speed's 5th gear is lower than the auto's O/D (4th gear). Your rpms will be a few hundred higher at highway speeds than an auto's would be if you both had the same diff ratios. So 4.88s and 5.29s are a little on the low side (high rpms) for a 5 speed/33s DD with little or no armor/extra weight.

Even with 3.91s, since you have a 5 spd, I probably wouldn't bother regearing just for 265/75s. Your 3.91s + 5 spd = about the same power as an auto with 4.30s. I ran 265s with my auto and 4.10s for years and always felt like it had good power so it's just not worth the $$ IMO unless you go to 33s.

If you want 255/85s or any other 33s, I suggest 4.56s because your is a 5 spd DD without extra weight. 4.88s would be best if your going to add 500+ lbs. or ever run 35s. 5.29s if you're gonna run 35s and have armor.

Note: This is all assuming you have the 3.4 motor. If you have the 2.7, there are better people to ask on here who have that motor.

Good point. Ive got the 2.7. Alas I seek more answers!!