Will 7.5" axle fit on 8.8"?

Fox Body · 02-22-2001, 05:50 PM

2 questions:

See, just got 3.55s installed and I need a new right axle (the one I have is slightly bent). The one I have isn't all that bad, but it would do good to get me another within the next month or two.
I was told by a pretty reliable source that the 7.5" axle would not fit in the 8.8", but then another more reliable source (?) told me that it would fit b/c they are the same axles. I have a 7.5" at home and would like to use it (save $$), but ..... Can I use a right axle from 7.5" rear?

Also, a friend told me that he has an axle from an 8.8, but he doesn't know which side it's from. Now I would assume that you would have to have the same side, right? Would I be able to use an axle from an 8.8" rear if it were a left axle?

"because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds

-------------------------------
'79 Mustang Coup
4" Cowl
Weld wheels (15x6;15x8)
Stock 5.8L
C4 w/ shift kit
1.5" MAC full length headers
Holley 750 CFM
Edelbrock intake
2.5" Off road H-pipe, 2-chamber Flowmasters
8.8" Rear end w/ 3.55s (Now that's more like it!)

Front: 225/60/15 Rear: 255/60/15 Eagle GT II
14 x 4" K&N air filter (getting the Xtreme setup soon)

02-22-2001, 05:57 PM

I'm assuming you're talking about the axle shafts inside the 8.8" axle. I don't think one from a 7.5" will work because i think they're smaller and have different size splines on the end. Both axle shafts from the 8.8" axle should be identical because they're no reason to manufacture them differently so it SHOULD fit in your car with no problem. Take the old one out and compare it to the new one to make sure and count have many splines are at the end of the axle shafts. I think they made a 28 spline and 31 spline axle shafts for the 8.8" but i don't know specifics about that. If the count is the same you can garauntee that it'll fit (assuming it's out of a mustang).

Unit 5302 · 02-22-2001, 06:58 PM

The axles should be the same.

Ford ranger 7.5" axles fit, drivers side only (the rangers diff isn't centered) but the Mustang's is. You should be able to use the 7.5" mustang axles no problem. Stock are both 28spline.

85cobra · 02-22-2001, 09:30 PM

They are the same length.

------------------
1985 Mustang GT Cobra
Mostly stock. Flowtech 1 5/8" lontubes, flowtech h-pipe, Flowmaster two chambers, Mac 2.5" tailpipes, MSD-6AL with Blaster coil, Weiand Stealth intake, Eibach springs, Monroe Formula GP's.

86GT · 02-22-2001, 11:05 PM

They are the same length and the splines are the same, as long as it came out of another mustang. Differential has to be centered like the 8.8 that way the shafts are the same length.

[This message has been edited by 86GT (edited 02-22-2001).]

Fox Body · 02-23-2001, 01:22 PM

Okay, so what I'm hearing is that the 7.5" won't work b/c of different splines, but 8.8" , either side, will work.

Thanks for the replies.

"because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds

-------------------------------
'79 Mustang Coup
4" Cowl
Weld wheels (15x6;15x8)
Stock 5.8L
C4 w/ shift kit
1.5" MAC full length headers
Holley 750 CFM
Edelbrock intake
2.5" Off road H-pipe, 2-chamber Flowmasters
8.8" Rear end w/ 3.55s (Now that's more like it!)

Front: 225/60/15 Rear: 255/60/15 Eagle GT II
14 x 4" K&N air filter (getting the Xtreme setup soon)

Unit 5302 · 02-23-2001, 03:06 PM

Well, I know for a fact the Ranger has a 7.5" rear end, I also know for a fact that Ranger axles fit my 8.8" 87GT. They both have 28 spline axles stock, same diameter.

The 7.5" axles off a 79-93 Mustang WILL fit your car, if your 8.8" came out of another fox Mustang. Look out cause some of the older 80's and earlier cars had the 6.75", those probably won't fit.

If they don't, e-mail me and I'll send you a check.

Anyway, since your friend has an 8.8" axle from a stang, who cares? So long as it's from a fox, if that's where your 8.8 came from, it'll fit no problem.

One other question, where did your rear end come from? The 1986-1993 5.0's had an 8.8" and all the 7.5" rear ends were the same width as the 8.8" units, the 87-88 Thunderbird Turbo's had longer axles, same deal with the SN95 and newer cars.

Bob · 02-23-2001, 06:28 PM

The axles out of a 7.5 Mustang rear end WILL fit the 8.8 and it doesn't matter which side, because they are the same length. Stock 7.5's and 8.8's use the same 28 spline axles. When I put the 8.8 FRPP rear end in my car, I used the axles out of the stock 7.5 that was in the car.

------------------
1985 Mustang GT

'85 GT 13.20 @ 105.8 / '72 Mach1
Long list...check website!!
My Website

02-22-2001, 05:50 PM	#1
Fox Body Mustang Maniac Join Date: Sep 2000 Location: GA, U.S.A Posts: 2,266	Will 7.5" axle fit on 8.8"? 2 questions: See, just got 3.55s installed and I need a new right axle (the one I have is slightly bent). The one I have isn't all that bad, but it would do good to get me another within the next month or two. I was told by a pretty reliable source that the 7.5" axle would not fit in the 8.8", but then another more reliable source (?) told me that it would fit b/c they are the same axles. I have a 7.5" at home and would like to use it (save $$), but ..... Can I use a right axle from 7.5" rear? Also, a friend told me that he has an axle from an 8.8, but he doesn't know which side it's from. Now I would assume that you would have to have the same side, right? Would I be able to use an axle from an 8.8" rear if it were a left axle? "because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds ------------------------------- '79 Mustang Coup 4" Cowl Weld wheels (15x6;15x8) Stock 5.8L C4 w/ shift kit 1.5" MAC full length headers Holley 750 CFM Edelbrock intake 2.5" Off road H-pipe, 2-chamber Flowmasters 8.8" Rear end w/ 3.55s (Now that's more like it!) Front: 225/60/15 Rear: 255/60/15 Eagle GT II 14 x 4" K&N air filter (getting the Xtreme setup soon)

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02-22-2001, 05:57 PM	#2
84stang83zephyr Guest Posts: n/a	I'm assuming you're talking about the axle shafts inside the 8.8" axle. I don't think one from a 7.5" will work because i think they're smaller and have different size splines on the end. Both axle shafts from the 8.8" axle should be identical because they're no reason to manufacture them differently so it SHOULD fit in your car with no problem. Take the old one out and compare it to the new one to make sure and count have many splines are at the end of the axle shafts. I think they made a 28 spline and 31 spline axle shafts for the 8.8" but i don't know specifics about that. If the count is the same you can garauntee that it'll fit (assuming it's out of a mustang).

02-22-2001, 06:58 PM	#3
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	The axles should be the same. Ford ranger 7.5" axles fit, drivers side only (the rangers diff isn't centered) but the Mustang's is. You should be able to use the 7.5" mustang axles no problem. Stock are both 28spline.

02-22-2001, 09:30 PM	#4
85cobra Registered Member Join Date: Mar 1999 Location: Vaughn,Ontario,Canada Posts: 23	They are the same length. ------------------ 1985 Mustang GT Cobra Mostly stock. Flowtech 1 5/8" lontubes, flowtech h-pipe, Flowmaster two chambers, Mac 2.5" tailpipes, MSD-6AL with Blaster coil, Weiand Stealth intake, Eibach springs, Monroe Formula GP's.

02-22-2001, 11:05 PM	#5
86GT Sniffed too much n20 Join Date: Oct 1998 Location: Ont, Canada Posts: 1,018	They are the same length and the splines are the same, as long as it came out of another mustang. Differential has to be centered like the 8.8 that way the shafts are the same length. [This message has been edited by 86GT (edited 02-22-2001).]

02-23-2001, 01:22 PM	#6
Fox Body Mustang Maniac Join Date: Sep 2000 Location: GA, U.S.A Posts: 2,266	Okay, so what I'm hearing is that the 7.5" won't work b/c of different splines, but 8.8" , either side, will work. Thanks for the replies. "because, no one’s really gonna be free until nerd persecution ends." ---Revenge of the Nerds ------------------------------- '79 Mustang Coup 4" Cowl Weld wheels (15x6;15x8) Stock 5.8L C4 w/ shift kit 1.5" MAC full length headers Holley 750 CFM Edelbrock intake 2.5" Off road H-pipe, 2-chamber Flowmasters 8.8" Rear end w/ 3.55s (Now that's more like it!) Front: 225/60/15 Rear: 255/60/15 Eagle GT II 14 x 4" K&N air filter (getting the Xtreme setup soon)

02-23-2001, 03:06 PM	#7
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Well, I know for a fact the Ranger has a 7.5" rear end, I also know for a fact that Ranger axles fit my 8.8" 87GT. They both have 28 spline axles stock, same diameter. The 7.5" axles off a 79-93 Mustang WILL fit your car, if your 8.8" came out of another fox Mustang. Look out cause some of the older 80's and earlier cars had the 6.75", those probably won't fit. If they don't, e-mail me and I'll send you a check. Anyway, since your friend has an 8.8" axle from a stang, who cares? So long as it's from a fox, if that's where your 8.8 came from, it'll fit no problem. One other question, where did your rear end come from? The 1986-1993 5.0's had an 8.8" and all the 7.5" rear ends were the same width as the 8.8" units, the 87-88 Thunderbird Turbo's had longer axles, same deal with the SN95 and newer cars.

02-23-2001, 06:28 PM	#8
Bob "Old School Gearhead" Join Date: Oct 1998 Location: Peru, Illinois Posts: 617	The axles out of a 7.5 Mustang rear end WILL fit the 8.8 and it doesn't matter which side, because they are the same length. Stock 7.5's and 8.8's use the same 28 spline axles. When I put the 8.8 FRPP rear end in my car, I used the axles out of the stock 7.5 that was in the car. ------------------ 1985 Mustang GT '85 GT 13.20 @ 105.8 / '72 Mach1 Long list...check website!! My Website