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Deciphering Fox Axels

I propose we work together to attempt to document rear widths in sticky worthy format for future people wanting to do rear axel swaps. There is a wealth of info here but some know it, some don't and others come in that ask it over and over again.

I have created a simple cad drawing of a basic rear assembly with what I consider relative dimensions and we have people out there that have rears laying around where we could get accurate measurements and list them out in the same format. As an example Vinniebirds info here  for Mustang, 85 TC and 88 Bird.

I have a 1984 Mark VII 7.5 Disk Break Rear I can measure out and also a 90 Mustang 8.8 (Mustang rears changed arround 90 something I believe)
I did my dimensions this way as opposed to the bearing to bearing measurement that Vinnie took because I believe the distance from housing flange into the bearing race is uniform from housing to housing and this is easyer to measure.

Also have Axel Measurements for both sides of axels because I know the Ranger and Areostar 8.8 axels are not the same from side to side. Most of ours will be the same.
And I know Chuck seems to have most of this in his head, possibly he can help us out.
heres some Info to get things going, Can anybody add or correct any of this? I will edit this post as new info is offered. 

Car = TBird/Cougar
Year =1983-1985
Ring Gear = 7.5
A = 61”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug
------------------------------
Car = TBird/Cougar
Year =1986-1988
Ring Gear = 7.5
A = 61”
B = 56”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug
------------------------------
Car = TurboCoup ONLY
Year =1987-1988
Ring Gear = 8.8
A = 61”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug
------------------------------
Car = Mustang
Year =1979-1993
Ring Gear = 7.5/8.8
A = 59.5”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug
------------------------------
Car = Mustang
Year =1994-1998
Ring Gear = 7.5/8.8
A = 61”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 5 Lug
------------------------------
Car = Mark VII
Year =1984-19??
Ring Gear = 7.5
A = 59.5”
B = 54”
C =
D =
E =
F =
G = 5 Lug
------------------------------
Car = Ranger/Bronco II
Year =1983-1992
Ring Gear = 7.5/8.8
A =
B =
C = 29-5/32"
D =
E =
F =
G = 5 Lug
------------------------------
Car = AreoStar
Year = 1986-1997
Ring Gear = 8.8
A =
B =
C =
D = 29-5/32"
E =
F =
G = 5 Lug
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Deciphering Fox Axels

Reply #1
Well no one will read it anyway....but ok.
Firstly, Vinnie's bearing surface measurement is to to the outer flange of the housing itself....and that is the proper place to do so.

From bearing surface to bearing surface...
8.8 Mustang rear 54"
7.5 TC rear (1985) 54"
7.5 '88 T-Bird rear 56"

From axle flange to axle flange (wheel mounting surface)
8.8 Stang rear 59.5"
7.5 TC rear 61"
7.5 '88 Bird rear 61"

I guess I'll have to do this...

Car = TBird/Cougar
Year =1983-1985
Ring Gear = 7.5
A = 61”
B = 54”
C =
D =
E =
F =
G = 4 Lug

Car = TBird/Cougar
Year =1986-1988
Ring Gear = 7.5
A = 61”
B = 56”
C =
D =
E =
F =
G = 4 Lug

Car = TurboCoupe only
Year =1987-1988
Ring Gear = 8.8
A = 61”
B = 54”
C =
D =
E =
F =
G = 4 Lug

Car = Mustang
Year =1979-1993
Ring Gear = 7.5/8.8
A = 59.5”
B = 54”
C =
D =
E =
F =
G = 4 Lug

Car = Mustang
Year =1994-1998
Ring Gear = 7.5/8.8
A = 61”
B = 54”
C =
D =
E =
F =
G = 5 Lug

On the Mk 7's they changed from the larger 11.5" disks in the rear to the 87-88TC type.  Not sure what that meant for axles/housings, etc.  The early ones with the larger brakes are going to be 1" wider overall than the Tbird/Cougars and the SN-95 Mustangs.

I have not measured/compared any 99-04 Mustang rear ends to verify if things changed.

There is no need for Dr and Pass side axle lengths...they are the same.....
Long live the 4-eyes!  - '83 Tbird Turbo

Deciphering Fox Axels

Reply #2
My 1984 Mark Rear has (had) the 11.5 vented disk so I will be able to supply that info. I'll try to get the measurments tonight.

One side of the Ranger and Areostar axels will swap with some of these housings.. I belive it is the left side axel. (I added that so we could include that info is somebody just wanted 5 lug swap with same axel leangths)

So for the one's above I was figuring listing them as...
Car = TBird/Cougar
Year =1983-1985
Ring Gear = 7.5
A = 61”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug


You definatly know more about this than I Chuck, and your listing is already more accurate. Are you offering to record the info in your post if we can make measurments and supply you with them?
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Deciphering Fox Axels

Reply #4
More Detailed Info...

"
To keep the stock rear wheel offset and drums, the '83-'92 Ranger/Bronco II Left (driver) side axle (29-5/32") from a 4cyl or 3.0L V-6 with the 7.5" rear end, or '86-'97 Aerostar RIGHT side axles (29-5/32") is what you want. They are the same rear axles, the center section is just on the opposite side when you compare the rear ends. The pumpkins are also off center unlike the Mustangs, so you will have to find two vehicles to pull axles from!
"

And the link
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Deciphering Fox Axels

Reply #5
Updated my chart but double checking where that 29-5/32" for the Ranger and Areostar leangth is measured from.
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Deciphering Fox Axels

Reply #6
Quote from: Jim_Miller;138280
My 1984 Mark Rear has (had) the 11.5 vented disk so I will be able to supply that info. I'll try to get the measurments tonight.

One side of the Ranger and Areostar axels will swap with some of these housings.. I belive it is the left side axel. (I added that so we could include that info is somebody just wanted 5 lug swap with same axel leangths)

So for the one's above I was figuring listing them as...
Car = TBird/Cougar
Year =1983-1985
Ring Gear = 7.5
A = 61”
B = 54”
C =
D = Same as C
E =
F = Same as E
G = 4 Lug


You definatly know more about this than I Chuck, and your listing is already more accurate. Are you offering to record the info in your post if we can make measurments and supply you with them?



I can mod my post I suppose.

One thing on the Ranger axles.....yes they will fit in the shorter housings...but unless the axle from the other side of a Ranger rear is 3/4" longer than the one used for the Mustangs....using 2 of them will narrow the rear track on a Tbird....
Long live the 4-eyes!  - '83 Tbird Turbo

Deciphering Fox Axels

Reply #7
Tbird axles (ALL..7.5 and 8.8) are 29-7/8"  (or 29.895") from the end of the axle (splined end) to the outer face of the lug flange....

They are 29-1/2" to the inside of the lug flange....

This measurement is the same for the 94-98 SN-95 Mustang 5-lug axles....
Long live the 4-eyes!  - '83 Tbird Turbo

Deciphering Fox Axels

Reply #8
Quote from: Chuck W;138293
I can mod my post I suppose.

One thing on the Ranger axles.....yes they will fit in the shorter housings...but unless the axle from the other side of a Ranger rear is 3/4" longer than the one used for the Mustangs....using 2 of them will narrow the rear track on a Tbird....


If I follow what your saying ...

You wouldn’t want to do that, besides it wouldn’t work.
The Diff in the Ranger/Areostar is offset the axels are Unequal lengths and the other axel wouldn’t fit the Mustang housing. (However it might fit another housing.. 88 Bird possibly?)
However using them in the 8.8 Stang housing gives you a 1.5 inch narrower bolt in 5 lug (correct?)
This is then .750 narrower per side

On my Stock 88 Bird I measure 1.5 inch of wasted clearance on the inside between the wheel well and tire on each side. (yes, I’m using the term “wasted” very loosely there.. but I like to live on the edge sometimes)
I’m hoping to utilize that clearance by having rims with a 6” backspace as oppose to the 5” (as best as I can measure with a tire on) backspace of the original 14” rims.

Now if my rims were a 5” backspace (or somebody else’s were) this 1.5 narrower rear 5 lug set up would be perfect.

Just allows a whole other option.

All this is why I would like a record of all the C,D,E and F Dimensions. What COULD we actually mix and match?
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Deciphering Fox Axels

Reply #9
Quote from: Chuck W;138295
Tbird axles (ALL..7.5 and 8.8) are 29-7/8"  (or 29.895") from the end of the axle (splined end) to the outer face of the lug flange....

They are 29-1/2" to the inside of the lug flange....

This measurement is the same for the 94-98 SN-95 Mustang 5-lug axles....


Here is where things start to get a bit confusing for me. Thats like the Dim I have for the ranger areostar axels (29-5/32")
Is that Relevant?
Or is end (splined end) to bearing race more important?

On the rear I'm working with for my Bird
the 1984 Mark VII axels Splined end to outer lug flange is at LEAST 2" longer than the 4 lug that came out of the 90 mustang rear.
 
Yet they still fit the housing for the Mustang (there's post on the site here about this someplace)

Not even sure an accurate measurment can be taken for the race area but thats what matters on a axel<-->Housing swap.
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Deciphering Fox Axels

Reply #10
Jim, you're making my head hurt....

Using the 29-5/32" Ranger axles in the shorter housing gives the same overall width as the Fox Mustangs... 59.5" .... in 5-lug.  I have no idea what the length of the other side Ranger axle is....The 29-5/32" dimension is from the splined end to the faqce of the lug flange.....  add .75" to that and you're at approx 29.9"....which is the Tbird/SN-95 axle length.

The Mk7 axles will be .75" + .50" = 1.25" longer than the Fox Mustang axles... Your early Mk7 axle housing is the same width as the Mustang housings...so yes...the longer axles fit in the same housing, even though the resulting overall width is 2.5" wider.
Long live the 4-eyes!  - '83 Tbird Turbo

Deciphering Fox Axels

Reply #11
I threw the info into a spreadsheet to make it more manageable.
I might have gotten all the information correct, I might not have...

Spreadsheet

updated 18:30 02/19/2018 Ye olde Griffshp.com is gone

Deciphering Fox Axels

Reply #12
Quote from: JeremyB;138359
I threw the info into a spreadsheet to make it more manageble.
I might have gotten all the information correct, I might not have...


Axle Spreadsheet

Looks right to me.  Glad to see the 99-04 stuff in there too.

I know Jim has an 84 Mk7 axle, which will be the same as my 84 SVO rear I have in the '80 XR-7.

There will probably be more than one Mk7 variation.

Thanks for organizing it better.
Long live the 4-eyes!  - '83 Tbird Turbo

Deciphering Fox Axels

Reply #13
Quote from: Chuck W;138304
Jim, you're making my head hurt....
[/COLOR]
lol Chuck!, my Dad's been telling me that exact same thing for over 40 years!
If it helps at all let me say I really do appreciate your help and humoring me. Of all the people on this site this would be WAY harder without your help. Seems to all be obvious to you, however confusing for me.
 
Jeremy, Wow that looks great Thanks!
 
First the comparison of the two, I think I said 2” difference, I was mistaken a bit.. here they are standing side by side

 
1990 Mustang Axel
Overall 29-1/4
Tip <-->beginning of machined surface (race) 26-1/4
Tip <-->ending of machined surface (seal) 27-3/4

 
1984 Mark VII Axel
Overall 30-1/2
Tip <-->beginning of machined surface (race) 26-1/4
Tip <-->ending of machined surface (seal) 27-3/4

 
Differance is more like 1-1/4
 
Also
The bearing Begins .750 into the end of the housing
The Backing plate Flange is 1” in from the actual end of the housing (outer edge of the seal)
The bearing is .625 wide
 
I will draw this bering area up tomorrow at work to better illustrate it, right now it’s late and I need to get sleep.
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Deciphering Fox Axels

Reply #14
Compairing to Jeremy's info from a ford document (pretty reliable source!)
It's saying the mustang axels I measured at Overall 29-1/4 (29.250) are actualy 29.180
I would be measuring .070 longer i think the Keeper grouve and end are much larger than .070 so I'm going to assume my measurment with the tape measure if OFF
 
you can bet my Mark VII measurment is off about the same.
 
I have a 0-18" calaper at work but nothing to measure 30" any more accurate than what I have.
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