Rear End Swap

[Tractor Dan]

Ok. I looked at the tech library and got most of my answer from there however i just wanted clarification. Do the 7.5 and 8.8 axles out of an Aerostar mount up to a Ranger without modification?

Also i currently have a 7.5 with 3.73 gears. I'm looking to upgrade as i went from stock tire size to 31 inch tires. I looked at the chart in the sticky and it said 4.56 gears is what i should use but could i get away with 4.10 gears? The 4.10 gearing setup seems easier to come by in my neck of the woods. Also if I would jump up to an 8.8 as long as it's out of a ranger will it mount up fine? I'm thinking as long as it's from 93 up it should work.

One last question here, sorry i have to ask so many questions. If i were to swap the rear end out doesn't the axle basically float down after you undo the U bolts? Then it's just a matter of disconnecting things? My dad was trying to tell me i won't be able to do it and it's hard, from what i know from working on and under it, it would be a time consuming task but with patience it can be done. I figure as long as i go with an axle that would mount the same and has the 9 inch drum brakes on it shouldn't be too hard.

Dan

 

[Mutant Pony]

The Aerostar had coil rear suspension. The axle shafts are longer as well.
4.10 gears work pretty good with 31's.
the brakes are probably the hardest part. As long as the shock bolts come out anyway.
It is possible to keep the brakes intact while you change axles but, that requires pulling the axle shafts.
You shouldn't reuse the u-bolts. I always cut the old ones and buy new ones. they can be hard to find in some places. I always buy 4 u-bolts, 2 center pins, and 4 quick clips and build up the rear springs while I'm there. The full set costs me about $50.

 

[Tractor Dan]

The Aerostar had coil rear suspension. The axle shafts are longer as well.
4.10 gears work pretty good with 31's.
the brakes are probably the hardest part. As long as the shock bolts come out anyway.
It is possible to keep the brakes intact while you change axles but, that requires pulling the axle shafts.
You shouldn't reuse the u-bolts. I always cut the old ones and buy new ones. they can be hard to find in some places. I always buy 4 u-bolts, 2 center pins, and 4 quick clips and build up the rear springs while I'm there. The full set costs me about $50.

What if my U bolts are maybe 6 months old? I replaced them when i put my lift blocks on because the old ones were too short. As for the brakes if i were to unhook them and then hook them back up to the new axle wouldn't i just have to bleed the air out of the lines? I think my shocks will come out fairly easy to, they are only a year or so old and i have an air compressor this time. Also how do you build up the rear springs? Just put in add a leafs or swap the whole spring assembly out for a thicker set?

Dan

 

[Mutant Pony]

When you tighten a u-bolt down properly it stretches. The second time they don't have that stretch so they end up causing a problem.
I usually just add a leaf. I get a used main leaf from another Ranger and cut just the eyes off then install it right below the main in the truck. Also a good time to replace any broken leaves.
If you're replacing a full spring you don't need center bolts or quick clips, bringing the bill down to about $35.
If your confidant with changing the brakes from one axle to the other than you have no worries. I clamp the hose so that the master cylinder doesn't run out. As long as you keep fluid in the master, bleeding is easy.
One more thing! You need a solid way to support the truck. a block of wood and a bumper jack won't do!!!

 

[Tractor Dan]

When you tighten a u-bolt down properly it stretches. The second time they don't have that stretch so they end up causing a problem.
I usually just add a leaf. I get a used main leaf from another Ranger and cut just the eyes off then install it right below the main in the truck. Also a good time to replace any broken leaves.
If you're replacing a full spring you don't need center bolts or quick clips, bringing the bill down to about $35.
If your confidant with changing the brakes from one axle to the other than you have no worries. I clamp the hose so that the master cylinder doesn't run out. As long as you keep fluid in the master, bleeding is easy.
One more thing! You need a solid way to support the truck. a block of wood and a bumper jack won't do!!!

I never thought about that on the U bolts but that does make sense now that you say that. As for supporting the truck i'm way ahead of you. I don't work under anything without it being secured and supported. I plan to either use my friends vehicle lift which is a frame lift or atleast borrow a floor jack from him and some good jack stands. Thanks for the help i'm somewhat more sure of myself now. I got a feeling between what i know and what my friend and his dad know we will be able to tackle this project eventually, if only money grew on trees. lol.

Dan

 

[Tractor Dan]

Ok. Well thinking of maybe going a new route. Simply because around here within the price and mileage range i have i just can't find the 4.10 gears in an axle. So what would it take to keep my current housing and swap the guts of it out to go from the 3.73 to the 4.10 set up? I know i'm looking at the ring and pinion but i'm unsure on what else. I'm debating on if it's worth doing it at the same time i replace my shackles and hangers or not. Really the shackles and hangers as of now are top priority. So the main question is what would it take to swap the innards of my 7.5 that has 3.73 gears and replace them with 4.10 gears. Also is it possible to do it myself or would i be better off having it done? Another question would the rear end still have to be pulled to swap the guts of the differential out? Only asking because if so, i would do it myself rather then pay my mechanic to pull it.

Dan

 

[Daringo]

Bump... same question, except I am considering going from a 4.10 to a 4.56 - how hard to swap out the gear only?

 

[Tractor Dan]

Ok. One last question as i have possibly tracked down a few explorer rear ends. They are from 95 on up year wise so it's the disc brakes. The question is on swapping the master cylinder which master cylinder do i need? There is a couple different options available. I'm assuming what ever matches what the axle has such as speed control or the proportioning vale.

 

[chazzone]

If you're smart, you will NOT clamp off the brake hose, regardless of what Mutant Pony told you.

This has the potential to cause a weak spot that can rupture later on.

All you have to do to keep fluid loss to a minimum is to keep the brake hose pointed up and wired up high.

Do not risk your life by doing something stupid like clamping off the hose!

Where the hell are the moderators here?

You should not allow someone to post dangerous disinformation on these forums.

 

[Tractor Dan]

If you're smart, you will NOT clamp off the brake hose, regardless of what Mutant Pony told you.

This has the potential to cause a weak spot that can rupture later on.

All you have to do to keep fluid loss to a minimum is to keep the brake hose pointed up and wired up high.

Do not risk your life by doing something stupid like clamping off the hose!

Where the hell are the moderators here?

You should not allow someone to post dangerous disinformation on these forums.

I wasn't planning on clamping it exactly like that. I was most likely going to get it up high like you said. Then find something close to the inner diameter of the line to act as a plug. Or something along thoose lines. Hadn't really figured out the exact path i was going to go though seeing as i have done enough plumbing i kindof had an idea not to clamp it. Though i'm wondering if by clamping he meant put it up like you said and tieing it off with a wire? Not saying that's what he meant but it could be.

Dan

 

[corrond56]

shouldn't need a new master cylinder or brake booster from what I have learned about the disc brakes. The parking brake will take modification though

 

[Tractor Dan]

shouldn't need a new master cylinder or brake booster from what I have learned about the disc brakes. The parking brake will take modification though

Hmmm. I thought i read somewhere that i would. Then again that was quite a few months ago so i might be thinking wrong. Never thought about the parking brake modification though, that shouldn't be too hard i wouldn't think. Then again depends on what it takes. I could see my luck being modifying the parking brake takes more work then swapping the axle. lol.

Dan

 

[Tractor Dan]

Ok. Real close here. This whole project is taking longer then planned on finding the parts but when looking for the best price, best deal, and having limited funds waiting is life. lol. So i got a friend who has a Ford 9 inch with 4.11 gears. Would that bolt up to my Ranger provided width and everything is the same. Mainly i'm trying to figure out that rear U joint at the axle, i would assume the 9 inch would have a need for a bigger yoke? I'm feeling out all my options. Probably just going to go with the one i found a salvage yard for $90 bucks. I refuse to disclose the name of the salvage yard until after i obtain my axle. Then yall can have a field day. lol. This place sells stuff dirt cheap. I was looking in my area and was looking at $400 this place is 100 miles away but $90 still makes the drive worth it.

Dan

 

[85_Ranger4x4]

I have heard you need a master out of a truck with ABS. If I have to I will try to stay as close to my trucks configuration as possible (std cab, longbox 4x4)

But that said I am going to try it first and see how it works with what I have.

 

[dla]

Ok. Real close here. This whole project is taking longer then planned on finding the parts but when looking for the best price, best deal, and having limited funds waiting is life. lol. So i got a friend who has a Ford 9 inch with 4.11 gears. Would that bolt up to my Ranger provided width and everything is the same. Mainly i'm trying to figure out that rear U joint at the axle, i would assume the 9 inch would have a need for a bigger yoke? I'm feeling out all my options. Probably just going to go with the one i found a salvage yard for $90 bucks. I refuse to disclose the name of the salvage yard until after i obtain my axle. Then yall can have a field day. lol. This place sells stuff dirt cheap. I was looking in my area and was looking at $400 this place is 100 miles away but $90 still makes the drive worth it.

Dan

You should read the tech library first - you're all over the place. Nobody can give much help until you get a little more focused. Aerostar->4.10->4.56->Explorer->9" - pretty scattered. Spend a little more time Googling - there is a BEST swap and you just need to see it and accept it.