Time for a lift - preparations to be made?

[kythri]

So, I'm ready to buy a lift for my '99 XLT.

I'm going to go with a 4" suspension lift, and I'm going to put 33" tires on 15" wheels under it.

Reccomendations on proper preparations?

I'm thinking that I want to re-gear the diffs - go from 3.73's to 4.10's. Would it better to buy upgrade products somewhere, and have the existing differentials re-geared, or should I look for a wrecking yard front and rear diff with 4.10's from the factory?

Any kind of preparation to be done to the transmission or transfer case?

 

[Blacksheep Josh]

from what i've read, as long as you re-gear to the ratio that will suit your tire size, your transmission and engine should be okay.

 

[Mbrooks420]

I'd get a huge tranny cooler. What motor do you have? If you aren't going the scrapyard route, I'd look if 4.56's might be better for 33's.

 

[kythri]

I've got the 4.0L SOHC V6 in it. 4.56's seem a bit much - I'm going to have it off-road more than it is now, but it's still going to be primarily a road vehicle, and I want to keep SOME mileage...

It's got a Limited Slip in it right - will that have to be replaced when re-gearing?

 

[Mbrooks420]

I'd have the clutches and springs replaced while you are in there. I read (maybe on the ranger station) about a way to rebuild it with an extra clutch disc and stiffer spring, so it takes more force to break the clutch free.

 

[HahnsB2]

I've got the 4.0L SOHC V6 in it. 4.56's seem a bit much - I'm going to have it off-road more than it is now, but it's still going to be primarily a road vehicle, and I want to keep SOME mileage...

It's got a Limited Slip in it right - will that have to be replaced when re-gearing?

4.56 will probably be better for millage, you don't want it lugging too much, with 4.10s and 33s you'll be higher geared than you are now, with 4.56s you'll be slightly lower geared than now.

 

[kythri]

I've got 3.73's now.

4.10's are higher, but 4.56's are lower?

Maybe I'm totally missing something here. Can someone explain?

 

[Mbrooks420]

A numerically higher number will have a lower gearing ratio. What he means is your final drive ratio(tire size, gearing, and trans gearing) will be higher (numerically lower) with 33's and 4.10, than with 3.73's and 235's.

 

[kythri]

That's what I thought.

So, if I've got 3.73's and 31's now, how will I be higher with 4.10's and 33's and lower with 4.56's and 33's?

 

[Glen4X4]

You've got to factor in your tire size as to what the gearing will seem like at the tires itself.

 

[Glen4X4]

you may want to look at this http://www.explorerforum.com/forums/showthread.php?t=67200

 

[kythri]

you may want to look at this http://www.explorerforum.com/forums/showthread.php?t=67200

Didn't read all 20+ pages, but I did searches of the thread for 4.10 and 4.56 and "gear" - didn't see too much there on determining proper gear ratio for tire size...

 

[Glen4X4]

I just figured it'd be helpful for you to see what size tires with what body lift you could do. You'd be fine to go to 4.10's or even 4.56 gears when we talk lifts and proper gearing and all that on here we don't feed a line of BS.

 

[kythri]

I just figured it'd be helpful for you to see what size tires with what body lift you could do. You'd be fine to go to 4.10's or even 4.56 gears when we talk lifts and proper gearing and all that on here we don't feed a line of BS.

Cool, cool - yeah, I've been here for a while, and am well familiar with the tire/lift thread, but it's much appreciated.

The lack of BS is also a big reason why I'm here - I'm just not as familiar with the gear ratio bit, and was confused as to how 4.10's would be higher, and 4.56's would be lower than the 3.73's I've got now.

Of course, now I just need to find someone who'll do the ring/pinion swap for me...

 

[Mbrooks420]

With 4.10's and 33's you'd be geared "higher" than stock. Like having 3.55's instead of 3.73's(the math there isn't right, just an example. With 4.56's and 33's it would be more like having 4.10's as opposed to 3.73's. It wasn't apparent that you weren't on stock tires.

 

[kythri]

Gotcha. Apologies for not providing all information, and I appreciate the input!