gears and tire size

[audiodude332001]

Hey everyone, planning on lifting the ex very soon. I looked at the axle code on the door and it says that I have 3.27 gears. The ex has great accelleration with the factory size tires on it, but how will 3.27 gears do with 32's or 33's. I know that my accelleration will suffer a bit, but will it suffer all that much?

Thanks,
Andy

 

[unclemeat]

It may be almost undriveable. I had 3.73 gears and 33s and it was a dog. I now have 4.56 gears. A 4.10 gear and 33s is basically a stock equal.

 

[DarkMan]

To maintian you current "power to the ground" feel, use a simple ratio. (Ahh algebra)

( (cur. gear) / (cur. tire diameter) ) X (new tire diameter) = (required gear)

If you've got 3.27s and are running 28" tires, 32" tires would require 3.73 gears to keep the same feel.

(3.27 / 28) X 32 = 3.737

It's important to remember that the size of the tire is not always the same as the actual, loaded diameter.

I went from stock size (measured at 27.5 inches) to 31x10.50s (my pirelli scorps where actually 31 inches when brand new). I also have 3.27 gears. The change to acceleration was very noticable. But since I can't afford new gears, I'm just putting up with it.

 

[audiodude332001]

Thanks DarkMan.
How noticable is it for you. Do you have an auto or 5 speed? I have an auto. Is accelleration still somewhat good? Im lookin at puttin on a set of 32's, but I dont have the money to spend on new gears. I might be able to have a buddy of mine install some new gears for me since he's done it plenty of times on his jeeps. What do you think would be a good gear for good accelleration with 32's? I was thinking either 4.10 or 4.56. What do you think? I don't want to loos too much accelleration power because I always accellerate fast right off the line. Also, I dont want my MPG to drop alot because of the new tires. Did you notice a significant drop in MPG with your new tires?

 

[audiodude332001]

Bump

 

[unclemeat]

4.56 may be a little low for 32s. I have a five speed 33s w/4.56 top speed is about 75. I would recommed a 4.10 for 32s, unless you plan to go with a bigger tire in the future.

 

[snowburns]

how would 3.55s work with a set of 32s? I can't afford to regear, but I'm buying new tires in the spring...

Also what would it be like if you had something like a 4.10 and went back to stock tire size?

 

[RiverRat]

IMHO 32" and 4.56 is great. 33" and 4.56 is good.

3.55 and 32 will be kind of doggy. 30" and 4.10s would be perfect.

From the tire and gear chart at 65mph, in drive (1:1) ratio.

30" - 4.10 - 2992 rpm

32" - 3.31 - 2259 rpm

32" - 3.55 - 2423 rpm

32" - 4.56 - 3112 rpm

 

[snowburns]

doggy, but doable right? I mean, if I have slower acceleration/top speed I'm cool with that, keeps me from speeding (usually I drive at the speed limit to 5 or 10 over)...as long as it's not bad, but if it's like a crawl I don't know what I'll do...

 

[audiodude332001]

Thanks everyone, A friend of mine will install the gears for me if I want him to. He just told me to get all of the stuff that I need and get the truck and the parts to him. I'm going to go with 4.10. All I need is a new Ring and Pinion, right? Where is the cheepest place to get these?

Thanks,
Andy

 

[unclemeat]

You need an install kit. You may want new bearings. You will need silicon sealer and gear oil. You may also need the friction modifer if you have a stock limited slip carrier.