3.73 to 4.10 swap advice please

fang619 · Mar 5, 2011

im looking to swap out my stock 3.73 ring and pinion on my 7.5 axle to a 4.10 ring and pinion set, just wondering how high the difficulty level is on this project because i am not familiar with gear swaps, any advice or related postings would help :icon_surprised:

88_Eddie · Mar 5, 2011

MY ADVICE:
first off...... you need to do A LOT of research. i've never done it myself (i plan on it in a year or so). it's a very precise process that can require some very expensive tools.

read all the articles in the tech library, check out youtube and other forums/sites. pirate4x4 has a good one
http://pirate4x4.com/tech/billavista/Gear_Setup/

i'd consult some of the member's on here before you do it as well.

secondly......i wouldnt even bother with the swap for a few reasons. that axle is weak and sinking $$$ into it isnt worth it. it would really suck if you spent all that $$$ regearing and then you blow up the diff or snap an axle shaft.

you could probably find a 31 spline 8.8 with 4.10 gears and get it installed for less than (or maybe a little more) it would cost to buy just the gears for the 7.5. or if you wanted to keep the 7.5, you could probably find one with 410's already in it too

it really depends on what tire size you're running and how hard you beat on it (giggity)

The Jester Race · Mar 5, 2011

http://www.pirate4x4.com/articles/tech/billavista/Gear_Setup

Edit: Damnit, beat me to it.

-Jester

fang619 · Mar 5, 2011

yeah i did want the 8.8 axle but i wasnt sure if i would be biting off more than i could chew if i would have to mod the leaf and shock mounts on the 8.8
any idea if i could just swap the two axles out if i did find a 8.8 with 4:10 gears?
money is kindve tight right now and i was planning on getting some gears from cl for $100 and getting a master install kit also but it might just be cheaper to get a whole new axle hopefully

disciplerocks · Mar 5, 2011

I suggest getting an 8.8 Ex axle with 4.10s in it already from the u-pull. Cheapest and easiest. Moving the spring perches is much easier than installing gears.

fang619 · Mar 5, 2011

would moving them just be cutting the factory welds and re welding them to the new postition?
im also worried about swapping out brake lines

b2rich · Mar 5, 2011

good luck finding a 8.8 and a d35 with 4:10s. Im currently looking for one and i finally found one in Michigan. hell if im going to pay shipping.
They are very rare to find in a stock application. :annoyed:

88_Eddie · Mar 5, 2011

fang619 said:
yeah i did want the 8.8 axle but i wasnt sure if i would be biting off more than i could chew if i would have to mod the leaf and shock mounts on the 8.8
any idea if i could just swap the two axles out if i did find a 8.8 with 4:10 gears?
money is kindve tight right now and i was planning on getting some gears from cl for $100 and getting a master install kit also but it might just be cheaper to get a whole new axle hopefully

you'll have to grind off the old leaf spring perches, they are on the bottom on an explorer 8.8. if you go to a u-pull to get the axle, including paying someone to weld the new perches on, buying new perches and the purchase of the axle, you could probably do the swap for less than $100.

and yes, if you're careful, you can reuse the factory perches.

there's a good article on the swap in the tech library. but like disciple said, welding the spring perches on is way easier than learning to install a ring and pinion.

b2rich said:
good luck finding a 8.8 and a d35 with 4:10s. Im currently looking for one and i finally found one in Michigan. hell if im going to pay shipping.
They are very rare to find in a stock application.

yeah they are, but he only needs an 8.8, unless it's a different vehicle that is under his avatar

disciplerocks · Mar 5, 2011

Junkyard here is full of them, but all the D35s are IFS. And he only needs the rear. Its 2wd.

b2rich · Mar 5, 2011

disciplerocks said:
Junkyard here is full of them, but all the D35s are IFS. And he only needs the rear. Its 2wd.

im still learning to read

my bad.

trail B2 · Mar 5, 2011

Your not going to find a 4:10 8.8 axle out there from an Explorer Rangers had them on special application only it's been said on here.There is quite a few 7.5 4:10s out there in mid 80s all were automatics My B2 came with one.The cheapest easiest way would be to buy one of those.

JPRanger03 · Mar 6, 2011

Just out of curiosity, what prompted you to want to do the swap? Mounting larger tires?

kunar · Mar 6, 2011

trail B2 said:
Your not going to find a 4:10 8.8 axle out there from an Explorer

sure you can! i have a 31 spline 8.8 with factory 4.10's and l/s sitting in my yard waiting to go in my truck. its even got disk brakes. you just gotta know where to look man.

06RangerXLT · Mar 6, 2011

ill be going from 3.55's to 4.10's on my 8.8

gonna do it when i do my input shaft seal and change my diff fluid.

i do alot of town driving, and even with my 235's it kills my gas mileage and power.
if i had anything other then a 4.0 id have to giver hell going anywhere.

Ranger Sport Honduras · Mar 6, 2011

i installed 4.10 gears on my 7.5" a while ago.
for what i saw(my cousin is a mechanic and he did the job, i was just helping) its not THAT hard at all.
it was a 3.73 and i got a set of 7.5" used 4.10 gears.
but i wont tell u to do it on your own because of that. maybe mine wasnt too difficult because we went from Ford oem to Ford oem.
id try to check with some mechanics, maybe someone could do the job without charging u a huge amount.

3.73 to 4.10 swap advice please

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