3.73 to 4.10 gears (or even 4.56)

kaspar139 · June 11, 2001

To all, I switched tire size from 265's to 33" BFG Mud, so I went to my dealer and was discussing the effects of going from 3.73 gears to 4.10s, and the mechanic said I wouldn't even notice the difference in power! Can this be true, or would I need to go to 4.56s????

DigUout · June 11, 2001

I haven't driven a truck with 4:56's and 33" tires, but I can tell you that with 4:10's and the 285's (close to your 33) I don't have the acceleration like I had with the smaller tire. I read all about MPG loss and rubbing, but had no idea that the power loss would be so significant. Yet the truck looks so good with larger tires, I hate to go back to the stock 245's.

If you're going to change gears anyway, I'd go with the 4:56, just in case you want 35's down the road. Least then you won't have to change gears everytime you get bigger tires. You may see a power increase with the 4:10's, but I don't think they will give you the maximum power you likely want. I'm trying to find some under the hood mods, (not affected by altitude) to give me some of my power back. Since we're in the same boat, let me know what you do.......

Frank S · June 11, 2001

I really can't believe the amount of power loss that you guys are having with the larger tire swaps.

I just went to a 32x11.50 Goodyear MTR and mine seems to be doing fine.

I guess that it has something to do with your engines making more power in the higher rpm ranges.

76BBSub · June 12, 2001

Maybe related to unspring weight, which is significantly more "important" than unsprung? I forget the exact relationship, but unsprung weight has several times more impact on performance than unsprung weight...and big tires are heavy, plus the effective gear change added in, I can beleive the problems you are seeing.

Jeff

kaspar139 · June 12, 2001

I think I am going to go with the Precision Gear 4.56 gears. They are available on Performance Products (http://www.performanceproducts.com) for 15% off for Father's Day sale. So I'll spend around ? on front & rear gears. NOW Where should I have em installed cuz I sure can't do it??? 76BBsub (or anyone), can you think of any place in Houston or would a 4Wheel Parts place be ok for this? I am definitely not going to the dealer, they will charge me an arm and a leg for it.

DigUout · June 12, 2001

Quote: from yZR2k on 5:51 pm on June 11, 2001
I really can't believe the amount of power loss that you guys are having with the larger tire swaps.

I just went to a 32x11.50 Goodyear MTR and mine seems to be doing fine.

I guess that it has something to do with your engines making more power in the higher rpm ranges.

What I am experiencing is loss of throttle response. I have no doubt I could still hit 95MPH+, on a straightaway. But what I've lost, or feels that I've lost, is a good percentage of the "step on it and pass no problem power." Previously (with the 245's) I had no doubt, with a clear line of sight, that I could pass on the curves and inclines. Now, I feel the need to be a little more cautious. Also, I've put away the toys for the summer, but I am wondering how it'll feel pulling a six place snowmobile trailer up 3Kft in elevation in 5 miles next winter?

Worst case scenario, I still have the stock rims and tires, and may change them out for the winter.

76BBSub · June 12, 2001

Probably one of the 4-wheel places in town could handle it. I had a buddy that got some new gears installed locally, forget the shop's name, but they screwed up anyway so you don't want to know em.

I think Internet Racer's Supply does that kind of stuff, too.

Jeff

kaspar139 · June 12, 2001

DigUout, that is the same feeling I have. The ol "4 Cylinder" feeling... man, can't wait to get those gears

y2kz71 · June 12, 2001

kaspar139, your new gear ratio is now 3.93 which is not too bad. Click on the link below for tire and gear conversion also speedometer calculator. Its a pretty cool site.

http://www.bncoffroad.com/tire_gear_cal.html

kaspar139 · June 13, 2001

But the actual is no longer 3.73, it is 3.57. Besides, I am simply going mad over the loss of throttle response, like DigUout describes.

kaspar139 · June 13, 2001

Ok, I am down to the death hour, as I am prepared to pay for the gears. I am looking for assurance that if I get the 4.56 instead of 4.10's that my trucks engine won't rev too high all the time, and won't run at 3000 rpms at 70mph! THoughts!!! I need help quick!

I know, I am acting like a pussE, but SHOOT, this is a tough decision. (I want to cuss, but it will put the ol **)