Axle Research

[rice_man]

I wanted to do a little research on the rear end I'd like to build. The ultimate end goal (years down the road, most likely) is a gen 3 coyote swap. In the meantime, I'm planning upgrades along the way, one step at a time.
The '82 GT had a 7.5 rear end. I want to eventually end up with a 5-lug 8.8 with 3.73 gears, a 31 spline carrier with fox length axles and trac-lok. Cobra brakes are in the works after that.
Junkyard parts are my drug of choice wherever possible.
If what I've read is correct (and this is what I'm trying to confirm):
1) Any 8.8 from 87-98 should be a more or less direct bolt in and be the same width as the current axle housing (shooting for a fox 8.8 if possible).
2) If I can find the an 8.8 carrier from a mid-90's explorer with t-lok and 3.73 gears, it should drop right in to a fox 8.8
3) There is no vehicle out there that has fox length 31 spline 5 bolt axles that'll work with disc brakes - I'll need to get Mosiers or something of the like.
4) Once I have the above sorted, I can follow the 5-lug swap thread stickied here in the forum to finish collecting the brake parts I want. I know I'll need a set of caliper brackets, but everything else should be easy enough.
Thanks for the help. I just don't wanna dork this up.

 

[AeroCoupe]

If you are planning on running slicks I get going to 31 spline but if it will primarily be a street car then 28 spline will work just fine. I would upgrade to some Moser replacement axles but other than that just rebuild the stock trac-lok, new bearings, new seals, and swap gears.

The 8.8 housing is the same from 86 through 98. If you are starting from scratch what you are wanting is the complete rear end out of a 94-98 GT. This will get you the 8.8, rear disc brakes and will bolt into your Fox and you just need to swap gears and rebuild it. These rear ends are 3/4" wider per side than the Fox 8.8 however there will be alot of choices in 9" wide wheels for this combo. When you step up to 10" you really need to measure to get the correct back spacing and you will need to roll the fender lip and most likely use a BFH to massage the inner wheel whlls but you would have to do this with a Fox width rear end.

 

[rice_man]

If you are planning on running slicks I get going to 31 spline but if it will primarily be a street car then 28 spline will work just fine. I would upgrade to some Moser replacement axles but other than that just rebuild the stock trac-lok, new bearings, new seals, and swap gears.

The 8.8 housing is the same from 86 through 98. If you are starting from scratch what you are wanting is the complete rear end out of a 94-98 GT. This will get you the 8.8, rear disc brakes and will bolt into your Fox and you just need to swap gears and rebuild it. These rear ends are 3/4" wider per side than the Fox 8.8 however there will be alot of choices in 9" wide wheels for this combo. When you step up to 10" you really need to measure to get the correct back spacing and you will need to roll the fender lip and most likely use a BFH to massage the inner wheel whlls but you would have to do this with a Fox width rear end.

I don't plan on running slicks, but I do plan on driving it like I'm mad at it. Plus, my luck is terrible. With a 3rd gen Coyote going in eventually, I want to fool with the rear end one time, do it right, and be done. I figure shooting for something good for over 500hp would be a good idea and from what I was reading, the 31 spline stands a better chance than the 28. If I have to buy axles either way, why not go bigger too?

My plan was to find a 94-95 cobra and rob parts off of it - this will get me front spindles and large discs on all 4 corners. I can use the axle housing off of it too.

My biggest reasons for posting was that I a) wanted to verify that my plan was sound and b) confirm that no vehicle ever brought to market had 31 spline fox length axles for a 31 spline carrier.

 

[Mustang5L5]

Yes, an 86-98 8.8 axle housing is the one to get. No changes to the housing itself, just the brakes and such bolted to it. You might be able to use a Mark 7 axle as well, but those seem to be harder to find these days as a lot of those have been scrapped by now.

There is a model explorer that does come with a 31 spline carrier. I don't know what model would have it though but that's an easy google search.

No fox-lenght 31 spline axles exist in the wild. I would go with some Moser's here as i've heard tales of the cheaper 31 spline axles twisting. Buy once, cry once.

 

[rice_man]

Yes, an 86-98 8.8 axle housing is the one to get. No changes to the housing itself, just the brakes and such bolted to it. You might be able to use a Mark 7 axle as well, but those seem to be harder to find these days as a lot of those have been scrapped by now.

There is a model explorer that does come with a 31 spline carrier. I don't know what model would have it though but that's an easy google search.

No fox-lenght 31 spline axles exist in the wild. I would go with some Moser's here as i've heard tales of the cheaper 31 spline axles twisting. Buy once, cry once.

Thanks! That's what I was hoping to find. Appreciate the info!

 

[chrlsful]

"...86-98 8.8 axle..."
who (model) has the 8 ? Is it earlier AND later?

 

[AeroCoupe]

Not really understanding your question.

 

[General karthief]

"...86-98 8.8 axle..."
who (model) has the 8 ? Is it earlier AND later?

My understanding:
86 through 98 mustang model years have the same axle housings.