Different axle ratios front/rear

[mrwhite2you]

Hello all, somewhat of a newbie here, so I figure I will introduce myself first and foremost. My name is Mike, I live in the Milwaukee area (WI) close to 3 of the Harley Davidson plants. Which works out well, because if I'm not wrenching my truck, I'm wrenching my bike. (no comments, please) I'm relatively new to the Chevy truck world... owned 4-cyl cars my whole life. After buying my house, I now have a need for a REAL vehicle. After about 6 months of shopping, I found a TX Suburban, very little rust, with new motor and trans. The price was perfect, so I snatched it up. Very few changes have been made, but many are planned.

Most recently, I got a good deal locally on a corporate 14 bolt FF with 3.73 gears. The truck came stock with 3.42's, and in WI the 4WD is a requirement in the winter, so now something else has to be figured out. I was planning on putting a plow on the front (got a used fischer for free from my brother) so a beefier front might not be a bad idea, but even if I keep the 10 bolt, I'll end up putting the 3/4 hubs on it just so I can have 8 lug axles all the way around.

In the meantime, I am wondering if I would be able to get around the difference in gear ratios simply by running 2 different tire sizes. Right now, I have 3.42 front and rear, and 27.5" diameter tires front/rear. If I up the rear to a 3.73 (with the new axle) and the rear tire to a 30"... would this work? I know the downside with this idea is now I have to start carrying two spares... 1 6 and 1 8. but this may be the most cost effective solution for now. That way, when I change the front axle/hubs to be 8 bolt and re-gear to 3.73, I can up the front tires to be 30" as well.

Or... if there is anyone out there with 2 3/4 ton rotor/hubs/spindles for a 10 bolt/D44 that they are looking to part with cheap...

[1FaastC10]

you *could* do that, however as you mentioned, you need 2 spares then, and it would look retarded. i would just look for a 3.73 geared 10 bolt/D44, and bolt it in place as well. 8 lugs all around, 1 size wheel and tire. it would make life much simpler for you, and any parts guy you come in contact with.

[1969 GMC]

i would try to find an 8 lug frontend too...and scrapped and junk Gm solid axle 4x4's are everywhere, so you should have NO problem finding an axle. finding one with the right gears might be a challenge, though.

remember, if you have different ratios in the front and rear axles, DO NOT drive on pavement in 4 wheel drive. stuff will break. but since 3.42 and 3.73 are so close, you would probably do alright in snow and mud, and other slippery stuff.

[Deltaskier]

I thought different ratios would trash your xfer case if you put it in 4WD. You're only allowed a .01 difference IIRC.

[The Dude]

it sounds like the rear end is not even under the truck yet so why dont you ust wait untill you have a 373 geared 8 lug front axle and swap them both at the same time.
but it would work with different size tires, you would have to calculate the exact sizes out. but this is the same idea used in a 4x4 tractor, different gears for different sized tires.