newer disc mustang rearend into fox,will it fit???

[pimpinphil]

hi,
i was wondering,will any of the newer model mustang rearends swap into my 88 fairly easily?i need a rear for it,and would like to have disc rear,just for the ease of break jobs,and better looks,also better breaking,and i have to run all new break lines anyway,and the emergency break looks like it should be fairly the same as well,but does it mount the same?thanks.
phil

 

[90mustangGT]

I'm not an expert here but I have heard that the axel on the newer SN95's is wider. Also you'll need a different master cylinder. Check out www.svo73mm.cjb.net lots of good info there.

 

[Daggar]

You can swap in the rearend from an 89-95 with no trouble. Just remember that you must also change some brake lines and the master cylinder and probably the proportioning valve.

 

[Mavrick]

I'm pretty sure that 94-95 axles are .75" wider than fox's on either side, and 96-present are something like 1.25" wider on either side than the fox's.

94-95 you can still use, with different offset rear wheels to make it fit right, but the 96-present are too wide.

 

[Daggar]

I believe you're right about it being wider Mav. Still... never heard anyone complain about the little bit of extra space in back. Would be great to have that extra room up front where you could really use it eh?

 

[trbkrb]

The info above is not exactly correct. READ Matt's website 90mustangGT listed above for the correct info. The 94-98 cars are the same size and are 3/4" wider on each side than the 79-93 cars. It will work fine with the 8" wide Ford wheels. Using 9" wide Ford wheels and it is a bit too wide. The 99+ cars are about 1.5" wider on each side and the complete rear end will not work on a Fox. You can get them to work, but that would require special offset and backspacing of aftermarket wheels.

 

[Daggar]

The info above is not exactly correct. READ Matt's website 90mustangGT listed above for the correct info. The 94-98 cars are the same size and are 3/4" wider on each side than the 79-93 cars. It will work fine with the 8" wide Ford wheels. Using 9" wide Ford wheels and it is a bit too wide. The 99+ cars are about 1.5" wider on each side and the complete rear end will not work on a Fox. You can get them to work, but that would require special offset and backspacing of aftermarket wheels.

Ok... that then brings me to ask a question. Granted, the 94-98 rear axles are .75 in wider. Why is that a problem? I mean, for most folks wanting to install a set of 275/40/17s on the back of the care over a set of 9 in wide wheels have to use a spacer to do it correct? (assuming a stock axle) How does less than a 1/3 of an inch on each side cause you to have to revert back to 8 inch wide wheels?

 

[trbkrb]

It is really only a problem with Ford 9" wheels. They will fit, but it just depends on if your car is lowered, or if you have rolled the fenders, and exactly how wide your tires are as to whether you will have rubbing or not. The wheel edge is moved out about 1/2" assuming the difference between a 8" and 9" wheel is split evenly on the inside and outside of the wheel. That moves the edge of the rear wheels out the .75" due to the longer axles and another .5" due to the wider wheels, or 1.25" total.

For example, I have the stock width rear end using Ranger axles. If I put the SN95 axles on my car, my 8" wheels will be out .75" further. Change to 9" wheels, and and the wheel itself would be out another .5", or right under the edge of the fender. (I just measured it) The tires usually stick out even further than the wheels (I have 255s and they stick out about 1/2" past the wheel), so the tire would likely hit the fender on every bump.

I can live with the additional .75" from the SN95 axles and it will work. I will probably do that in the future, but adding 9" wheels with the SN95 axles would be more effort than I want to put on it.

Not saying you can't do it, just that it will require some other steps to make it work right, or you can use aftermarket wheels that will fit.

Good luck!

 

[Daggar]

Ok... so basically with what little I know about this already and what you've told me so far then that extra .75 in on each side would be a good thing (assuming that the information I've gotten so far about needing spacers for a 275 series tire on the stock axle). I might however, have to roll the fenders (car is at stock height at the moment). What I'm gathering though is that the extra width gained from a 94/95 axle would be a better alternative to using a spacer (I'm not enthusiastic about spacers) on the stock axle. Tell if I'm wrong but... extra space **IS** required (regardless of how you get it) to accomodate the size tires I'm talking about.

 

[TheUser]

I don't know about the spacers and all, but the reason for that is probably because, without spacers, the tires would hit the quad shocks...some people flip the quad shocks - i'm not sure if that eliminates the need for spacers or not...look into it.

I should also mention that there is a kit you can buy to make the SN95 rear discs line up correctly on a fox from www.northracecars.com, but that's adapting the SN95 spindles and discs, not sure about the whole rear end.

 

[Daggar]

Great! I'll give them a call and see if this kit will work for the 86 or if it's for 87-89 crowd only.

 

[trbkrb]

Using the SN95 rear setup will help with the spacer issue if you are using about a .75" spacer. As I said before, I have 8" wheels and 255 tires on stock width axles. I can just squeeze my finger in between the tire and the shaft of the quad shock, and my quads are already flipped. With a 9" wheel and stock width axles, I could not use the quad shocks with any tire wider than the 255s since they would hit the shafts.

Yes, the North Racecars brackets will work with an 86, as they just relocate the calipers so you can use the stock length axles with the SN95 disc setup. The 8.8 housings are the same from 86-98. Only the axles are longer on the 94-98, and of course the stock disc brake brackets.

 

[Daggar]

The 8.8 housings are the same from 86-98. .

If the housings are all the same... why is it each time I call and talk to companies about doing a 5 lug rear disk brake conversion for my 86 they tell me that they don't have a kit for that? Plenty out there for 87-89 but nothing for the 85-86. I did speak to one guy from Springfield motorsports (Virginia I think) that said he had a complete package for the 86 but it included some modified axles (the axles they use for 87-89 would not fit). I was all giddy and excited about the thing until the sticker shock. $3950 for the whole package. The package was all quality stuff. Baer brake calipers and disks front and back 4 Cobra R 17" knockoffs and 275/40 tires but wow!!! That's allota dough I'd rather have under the hood. I guess I'm asking... what are the differences in the axles and other parts where brakes and suspension components are concerned between the 86 and 87 Stang?

 

[trbkrb]

LOL!!! The ignorance of some people....The people you talked to are just going by what the "part was designed for". MANY guys with the pre 87 cars have changed to SN95 setups and even the M2300K Cobra brake kit. It just may not all quite fit exactly like it was designed, but it can be made to fit. Problems are the ebrake and the MC/ booster setup. Stangplus2birds on here has the Cobra kit on his 86, so that kind of kit WILL work. They probably just want to cover themselves on the legal end since it was "designed for 87-93" cars.

Read Matt's website in the 2nd post. He goes over all the interchangeable parts and how you can convert. If a kit will fit a 87-93 rear, then it will fit a 86.

The only differences in the 86 to 87 V8 brakes are the 86 has a 2 port MC, vs 3 port on the 87-93, and the ebrake adjustment is a bit different. The front spindles and brakes standard on the 86 are the smaller "4cyl" brakes that came on the 87-93 4 cyl Mustangs, and are not the same as the V8 brakes and spindles, so the SVO/MarkVII rotors do not work on 86 and earlier cars unless you change the spindles. But they can be changed to SN95 spindles that are the basis of most all 5 lug big brake conversions easily. Plus the brake lines are SAE thread instead of metric. I think that covers it.

 

[Daggar]

Sweet... i think that covers it for now. In a nutshell, I can use any 87-89 rear didsk 5 lug conversion kit for my 86. The fronts I pretty much have a handle on already. Thanks for the info.