Changing out 7.5" rear to 8.8"

[adsm08]

It says I have a 7.5" 3.73 ration gearing, 28 spline axles.

Then you have a 7.5. The front of the 8.8 axle housing is deeper to accommodate the wider gear. It WILL NOT WORK with a 7.5 gear set. The pinion depth and backlash can never be correct. If you truly had a 7.5 gearset installed in an 8.8 housing there is no way on God's green earth that it has 189,000 miles on it.

 

[agrich2]

Thanks for the info

Thanks to all the people in this forum I now see the light. I have done all the major work on my truck myself but I don't know anything about rear ends. I am learning the hard way.
THe guy at the local driveline shop don't know jack about Ford rear ends. That is correct as someone pointed out.
I have a 7.5 and all of the 8.8 gears I just ordered are not going to fit in it.
Thanks for posting the pics of the diff covers, a picture is worth a thousand words.
Now the real question is do I just keep moving towards wholesale swapping out to put a 8.8 under my truck or send parts back and get 7.5 parts to rebuild what I have. I guess I can at least keep the axles I just ordered from Superior. They are supposed to be the same.
The one thing is that I will have to go buy a used axle housing and I can rebuild it at my leisure while I drive my truck. If I pull my axle housing I am committed from start to finish.
I really want to do the job right and get the axle housing painted up nice so it doesn't rust up. We have a lot of deicing around here and that salt chews up everything under the truck.

 

[infantry grunt]

with the money you are planning to invest in this rearend,I would go to a junk yard and buy an explorer 8.8.got mine for $275 99'explorer rear w/disc breaks.just check it out real good before you buy it.i used my old leaf spring perches and paid a professional welder to come to my house to weld them on cost $40.thats what i would do if you are wanting to upgrade

 

[straycat]

I have a 99 Ranger 4x4 3.0L X-cab.
Suprisingly, I have a 3.73 7.5" ring/pinion in a 8.8" axle housing. Came stock and I am the original owner.
I have 190K on the truck and the rear end is starting to show signs of wear.
I am going to change all the rear differential parts and upgrade to an 8.8" 3.73 ring/pinion with all new spiders gears/bearings/seals...ect.
The main question is will I need a different carrier or will I be able to use what I have and bolt the 8.8 kit right to it???
Everything I read in the tech sections states it's a direct replacement.

Thanks,
Aden Rich

What size tires are you running? You might as well get a 4:10 over a 3:73. I run this gear with 33x12.5 KO tires and I love the gearing. I never heard of an 8.8 rear housing using a 7.5 set up?

 

[agrich2]

8.8 rear end

There is not such a thing.
The local guy at the driveline shop led me astray.
He saw the notches in the lower differential housing and told me it was a 8.8.
Once I saw several pics of the covers for both, I have a 7.5.
I am running 31X10.5.
This is my daily driver so I don't need bigger tires.
I don't 4X4 a lot, but I do haul loads of gravel and tow so I was thinking the 8.8 would be the way to go.
I have seen posts about changing the rear end to and Exploder but wouldn't that be a bunch more work.
How does the emergency break work with the other setup?
Would it just be easier to find a 8.8 rear end with 10" drums???
I thought about 4.10's but then I would have to change the front as well-more work

 

[Gotta_gofast]

Thanks to all the people in this forum I now see the light. I have done all the major work on my truck myself but I don't know anything about rear ends. I am learning the hard way.
THe guy at the local driveline shop don't know jack about Ford rear ends. That is correct as someone pointed out.
I have a 7.5 and all of the 8.8 gears I just ordered are not going to fit in it.
Thanks for posting the pics of the diff covers, a picture is worth a thousand words.
Now the real question is do I just keep moving towards wholesale swapping out to put a 8.8 under my truck or send parts back and get 7.5 parts to rebuild what I have. I guess I can at least keep the axles I just ordered from Superior. They are supposed to be the same.
The one thing is that I will have to go buy a used axle housing and I can rebuild it at my leisure while I drive my truck. If I pull my axle housing I am committed from start to finish.
I really want to do the job right and get the axle housing painted up nice so it doesn't rust up. We have a lot of deicing around here and that salt chews up everything under the truck.

Another example of how valuable a "knowledgeable" shop can be compared to your average idiot. Just for giggles, I would take the truck to them and ask them what rear end it is again. If they still say 8.8, give them your 8.8 guts and tell them to install it. haha.

Your easiest option is to find an 8.8" axle from another ranger with the same gearing as your front axle (3.73:1). This will literally swap right in. For budget minded folks, find one with a trac-lock limited slip diff. For some more bones, look for one with an open diff and install a powertrax no-slip locker (ask me how much I love mine!). In my old V8 ranger I used an explorer 8.8 31 spline axle, which is not too complicated to install but needs some special touches like relocating the spring perches. Explorer axles are roughly 1.5" wider and have larger axle tubes so new larger U bolts will be needed.

I paid $200 for my explorer 8.8 axle. I would suggest paying no more than $200 for a complete drop in 8.8 from a Ford Ranger. Return the parts you have and purchase a complete 8.8. If you have any "rebuild" parts for the 8.8 you may wish to keep them to rebuild the new axle. But stuff like gears and axle shafts may be overkill (especially on a 3.0L).

 

[straycat]

Another example of how valuable a "knowledgeable" shop can be compared to your average idiot. Just for giggles, I would take the truck to them and ask them what rear end it is again. If they still say 8.8, give them your 8.8 guts and tell them to install it. haha.

Your easiest option is to find an 8.8" axle from another ranger with the same gearing as your front axle (3.73:1). This will literally swap right in. For budget minded folks, find one with a trac-lock limited slip diff. For some more bones, look for one with an open diff and install a powertrax no-slip locker (ask me how much I love mine!). In my old V8 ranger I used an explorer 8.8 31 spline axle, which is not too complicated to install but needs some special touches like relocating the spring perches. Explorer axles are roughly 1.5" wider and have larger axle tubes so new larger U bolts will be needed.

I paid $200 for my explorer 8.8 axle. I would suggest paying no more than $200 for a complete drop in 8.8 from a Ford Ranger. Return the parts you have and purchase a complete 8.8. If you have any "rebuild" parts for the 8.8 you may wish to keep them to rebuild the new axle. But stuff like gears and axle shafts may be overkill (especially on a 3.0L).

Haaa haaa, good one, Bro!!!! Good price for the 8.8 you got.

 

[ZMan]

Haaa haaa, good one, Bro!!!! Good price for the 8.8 you got.

Pull-a-part has em for 100, though you have to remove them yourself, which is kind of hard sometimes.

For the op: Hooking up the ebrake isnt hard with a explorer axle, they have an internal drum so your cables hook up to it the same.

 

[agrich2]

Exploder rear end

What do you do about the width difference in the rear ends?
Do you just let you tires hang out another 3/4" on each side, or do you get rims that setback that distance?

Having trouble finding a Ranger rear end where I am located.
Is there a ton of soccer moms out there driving the Exploder into the ground which is why there are more rear ends?

 

[85_Ranger4x4]

What do you do about the width difference in the rear ends?
Do you just let you tires hang out another 3/4" on each side, or do you get rims that setback that distance?

Having trouble finding a Ranger rear end where I am located.
Is there a ton of soccer moms out there driving the Exploder into the ground which is why there are more rear ends?

Actually then it would match the front.

Right now they are slightly different... and I bet you never noticed.

'83-'89 w/D28 axle:
58" front / 56.5" rear

'90-'92 w/D35 axle:
59.5" front / 56.5" rear

'93-'11:
59.5" front / 58.5" rear.

Explorers ('91-'01) are 59.5" on both ends.

http://www.therangerstation.com/forums/showthread.php?p=1184789#post1184789

 

[Gotta_gofast]

On my old ranger it was narrowed to fit wide drag tires. on a stock application, if it looks goofy you can find 1/2" wheel spacers for the front.

 

[Gotta_gofast]

Actually then it would match the front.

Right now they are slightly different... and I bet you never noticed.

'83-'89 w/D28 axle:
58" front / 56.5" rear

'90-'92 w/D35 axle:
59.5" front / 56.5" rear

'93-'11:
59.5" front / 58.5" rear.

Explorers ('91-'01) are 59.5" on both ends.

http://www.therangerstation.com/forums/showthread.php?p=1184789#post1184789

Damn, I gotta go measure my axles tonight. lol

 

[85_Ranger4x4]

Damn, I gotta go measure my axles tonight. lol

Now that you know it, it will bug the heck out of you too.

At least it does me...

 

[Gotta_gofast]

Yea the truck is muddy from making my own path on a new jobsite so I don't feel like crawling under it but yes it does kind of bother me. Most all of the parts interchange with the explorer so it would make sense.

 

[upnsmoke]

Pull-a-part has em for 100, though you have to remove them yourself, which is kind of hard sometimes.

Good point about pulling it by yourself, that really can be time consuming and a little labor intensive. Not to mention you have to be a human fork truck to carry it any significant distance it by yourself. My pull a part sells them for 65 without drums. I found my most recent one in a 90 Ranger. Had 10" drums and the bed was off the truck and the driveshaft was already cut, but near the axle so I got an extra yoke. I wasn't there for an axle, but I couldn't walk away from that. Then it took me almost as long to carry/drag it to the gate as it did to pull it from the truck.