Gearing question

[georryan]

So, if you had the option of putting in a 4.10 locking rear diff or putting in a 4.30 and changing the front diff as well (Manual tranny), which would you choose? The 4runner is lifted 3" as well with larger tires (I believe they are 31" or 32" tires)?

Would the 4.30 gearing make the speedo that is setup for 4.10 more accurate (if the 4runner is lifted with larger tires)?

Will the 4.30 gears will hurt the mileage some right (not that the lift doesn't)?

 

[techno]

Personally I would only bother doing 4.30's if I went up to 33" tires and did plenty of offroading. 4.10 is fine with 31-32's. The speedo difference is very small and speedos come out of the factory with a 10% tolerance anyway.
There are plenty of good threads on the forum that debate diff gear ratios and some go right into the mathematics of it all too if you are interested.
BTW, a lift does virtually nothing to your milage, but it can affect your braking performance.

 

[RunnerUp]

i would go for the locker, unless you care more abt onroad performance.... and even then, go to 4.56s or 4.88s, 4.30s wouldnt make a big enough difference to make it worth the AMAZING amt of money required to change gear ratio's... and even then, if your going to swap gears out, you need to put lockers in... that way you only pay labor once

 

[georryan]

Thanks for the reply. I'll keep looking. Most of the posts I'd read here and on yotatech all were talking about 35" tires and gear ratios closer to 4.88 and up.

I never ran across that mathmatics thread, I'll look for that as well. Thanks.


RunnerUp:

Well I was looking at a recycle parts place and was able to get a toyota rear locker equipped diff for under 800. All I would need then would be a harness, the computer and the button (along with the welding and such for retrofitting it). It was a 4.10 gearing as well. I just wasn't sure how well that would do with a lift and for moderate 4wheeling. So I was curious if it would be better worth my effort to just go wtih a 4.30 geared one and then switch out the front diff to the same.

I suppose if I was going to really get into more intensive 4wheeling then I'd want the 4.56 gears as well and go with an ARB locker or something? The price for doing that looks to be more than 2k. So going with just the rear diff seemed to be a reasonable and cheap option, although I haven't priced out what a front diff would cost me.

Then again, I'm very new to all this. This will be my first 4x4 rig, I've always owned subarus and such and have only had friends with wheelers, so I'm still soaking up info. Thanks for the replies.

 

[RunnerUp]

okay, you are right that 4.88s are better suited for 35's, but that would really only matter if you do a majority of highway driving. 4.56's are desired for 33"s. if you want to do more reading check out this thread over on yotatech.

http://www.yotatech.com/showthread.php?t=58258&highlight=supercharger

it has ALOT of info on gearing for the 3.4 with 33"s and 35"s.

as far as regearing front and rear and going with ARB lockers front and rear, your right, it would prob cost around 2k. i know on trail-gear.com he has already set up 3rds with 4.88's and an ARB for around 1399. add in the compressor and your at 1500 w/o labor (though the already set up 3rd member would make it MUCHO easy to install in your axle housing.

http://www.trail-gear.com/toy-diffs.html

as far as buying a used differential and elocker, i wouldnt do it. you dont know how it was used or abused, and elockers seem to fail alot if their owners dont take care of them.

 

[georryan]

Wow, thanks for the replies. That gives me a lot to go over.

So, were there any manuals that came with 4.30? I'm assuming it is a 4.10. I better figure it out when I get a hold of the rig.