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Topic: 7.5" axles into an 8.8"? (Read 3245 times) previous topic - next topic

7.5" axles into an 8.8"?

Ok guys.  Been reading all I can find on this.  I swapped the Fox mustang 8.8 into my Bird last weekend.  Now I can swap over the axles, backing plates and brakes for a stock width wheel track right?

7.5" axles into an 8.8"?

Reply #1 –
If disc brakes then yes. Drums no. The axle tubes on the drum brake rear are longer.

I had to buy an 88 XR7 8.8 to keep the 10" drums and have the correct track width. Also, as a FYI, if you want stronger axles buy aftermarket axles for a 93 Mustang Cobra. They are the same length as the Thunderbird/Cougar axles. I've got 31 spline Moser axles for a 1993 Cobra and a 31 spline Traction-Lok and they fit like factory in the 88 XR7 housing.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

7.5" axles into an 8.8"?

Reply #2 –
Ya I was meaning drums.  Guess I will deal with spacers or new rims with a different back spacing.  At least until an SN95 diff comes up for sale.  Cougar and TBird parts are rare around here.

7.5" axles into an 8.8"?

Reply #3 –
They are rare here too. With the newest ones now 30 years old I have a hard time finding parts, especially since most rusted away 10 years ago. I ended up getting the 88 XR7 rear from a forum member in Iowa about 5 years ago. It was a process to get it even though it was only a state away...
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

7.5" axles into an 8.8"?

Reply #4 –
Ron, is there any V8 '94-'98 Stangs being parted in your area? That would have everything you'd need, pretty much....

'99 stuff would work, but the rear housing is wider yet than a Fox CatBird so you'd be going the other way with that setup, but an option if need be, worst case.

Edit; if you wanted disc brakes...drums, no idea. I converted my TC rear to drums a few years ago, wasn't hard, Ranger axles, '88 Crown Vic drums (10 inchers), and then I used the stock Sport backing plates and brake shoes. Worked great. Had to put 5 flat washers over the studs on one side before the drum went on, else the drum sed the backing plate and screeched.

I sold that rear to a guy here, was a bit of a job getting the rear into the trunk of my Lexus. Ughh
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

7.5" axles into an 8.8"?

Reply #5 –
Should have asked but are you going 5 lug?
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

7.5" axles into an 8.8"?

Reply #6 –
What year car are you working on?  On my 84, I swapped the 7.5 for an 8.8 from a 88 mustang lx. The axels, drums and backing plates bolted right back on like the 7.5.
84 COUGAR/90 HO, 1.7RRs, performer RPM,700DP, equal length shorties, stainless EXH ,T-5,Hurst pro-billet, KC clutch, 8.8/ 4.10s, line-lok, bla ,bla, bla.
71 COMET/289,351w heads, 12.5 TRWs, 750DP, Liberty TL, 9"/6.00s, 11.9x @112 , bla,bla,bla.

Never shoot your mouth off, unless your brain is loaded! ....I may get older, but I'll never grow up!....If you're not laughing, you're not living!  :laughing:

7.5" axles into an 8.8"?

Reply #7 –
On the older (pre '85) you can, but I think he's got an '87 or '88, so that's not an option.
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

7.5" axles into an 8.8"?

Reply #8 –
Mines an 84.  I wasn't planning to go 5 lug right now.  But down the road at some point.  If I swapped a rear in with disc brakes I wouldn't be taking a step backwards and bolting drums on it. That doesn't make sense to me. 

I guess since I want to change the fluid in the diff anyways I will rear it all apart and see if they will interchange and give me the width back I want.  If not, I'm not too concerned really.    SN95  GT's  are hard to find up here too and every idiot that is parting one thinks they are on a gold mine.

7.5" axles into an 8.8"?

Reply #9 –
With an 84 the rear is the same width as the Mustang. Just swap your brake parts over to an 86-93 Mustang 8.8 and you should be good.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

7.5" axles into an 8.8"?

Reply #10 –
That may be true of American Birds, but not true of the Canadian versions.  The wheels definitely set in further.

7.5" axles into an 8.8"?

Reply #11 –
Interesting..

Got a pic of how it sits?
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

7.5" axles into an 8.8"?

Reply #12 –
Quote from: 1WLD BRD;465212
That may be true of American Birds, but not true of the Canadian versions.  The wheels definitely set in further.

Mine is Canadian. The only way the wheels will sit further in is if you use the Mustang axles and drums. They are 3/4 " shorter per side.
84 COUGAR/90 HO, 1.7RRs, performer RPM,700DP, equal length shorties, stainless EXH ,T-5,Hurst pro-billet, KC clutch, 8.8/ 4.10s, line-lok, bla ,bla, bla.
71 COMET/289,351w heads, 12.5 TRWs, 750DP, Liberty TL, 9"/6.00s, 11.9x @112 , bla,bla,bla.

Never shoot your mouth off, unless your brain is loaded! ....I may get older, but I'll never grow up!....If you're not laughing, you're not living!  :laughing:

7.5" axles into an 8.8"?

Reply #13 –
It's a complete mustang differential so....  Ya it has the mustang axles and drums.  But that is what the question was.  I can swap the 7.5 axles and brakes onto it and get my width back right?

7.5" axles into an 8.8"?

Reply #14 –
Where abouts in Ontario are you quickshift?  I work in Hamilton and live in Cayuga