Idendify a Rear Anyone?

[etel64 10]

This is the rear in my 69 Mach. I dont think this is the original. I know its an open rear and am interested in making it a Traction lok. Can I buy the center section if it is a 8, 8.8, 9" rear?

[maxum96 32]

It's an 8". If your car is an original Mach1, someone took the original 9" rearend out and put that 8" in. Mustangs with 351 or larger engines came factory with a 9" rearend. Boss 302 and 65-66 Shelby Mustangs were the exception to that rule.

Edited November 12, 2012 by maxum96

[JTG 10]

I thought stock Mach I cars with a 351 2V came with an open 8" rear?

[maxum96 32]

I thought stock Mach I cars with a 351 2V came with an open 8" rear?

 

 

My car was an H code (351w 2V) car from the factory. Mine came with a 9" rearend.

[Lemon Owner 11]

my car was an h code (351w 2v) car from the factory. Mine came with a 9" rearend.

 

x 2

[rawlinss 14]

http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=vornhagenmotors&ftab=AllFeedback&rt=nc&myworld=true

 

I was able to convert my 8" rear end to a 3.55 POSI rear end for $650 plus shipping from the contact above....

 

I saved him as a favorite seller in my ebay account, he doesn't appear to have anything on line currently, but you might be able to contact him)

Edited November 12, 2012 by rawlinss

[TonyV8 10]

So this is a 9 inch rear end more round than oval?

 

[02Lightning 10]

So this is a 9 inch rear end more round than oval?

 

Yes, another way you can tell from the other side is one of the bottom bolts you can't use a socket on it. You have to use a open or box end wrench on it to get the nut off. On an 8" you can use a socket on all of the nuts.

[miketyler 15]

Here's a good page I have bookmarked that explains the variations and differences in 9" rears and some 8"

 

http://www.kevinstang.com/Ninecase.htm

[LindenBruce 27]

This is the rear in my 69 Mach. I dont think this is the original. I know its an open rear and am interested in making it a Traction lok. Can I buy the center section if it is a 8, 8.8, 9" rear?

 

For the 8" and 9" the answer in short is yes, you can buy a different center section. The 8.8" is set up more like a GM 10 bolt, the carrier is integral with the housing. Bruce

[etel64 10]

Thank you all. that was very helpful. Looks like I should be looking for a 8" locking center section. I want to wear the tires evenly.:cool2:. Would the drive shaft need to be different? are the yokes different?

[RPM 1,190]

The traction loc or Detroit locker has nothing to do with the shaft or yoke. Bad news is that 8"ers are usually more expensive than a 9".

Edited November 23, 2012 by RPM

[cobra3073 24]

As Maxum 96 noted and/or inferred, ALL 1969 351 (2V and 4V) Mach 1 should have a 9" ring gear set from the factory. Most of them share a 28 spline axles but some might have the 31 spline axles. The 302s would have an 8" or 7 3/4" ring gear but that application was not available for the 1969 Mach 1.

 

I missed it but if you post up your rear end code, we should be able to tell you exactly what your Mustang came with from the factory.

 

Also, as noted, the 8'' stuff might be more expensive to acquire than the 9" but their are "providers." The easiest approach would be to just drop in a complete 9" carrier with the 28 spline as you would not have to change your axles shafts unless you go to 31 or 35 spline.

 

BT

[maxum96 32]

Most of them share a 28 spline axles but some might have the 31 spline axles. The 302s would have an 8" or 7 3/4" ring gear but that application was not available for the 1969 Mach 1.

 

 

Only the big block cars got 31 spline axles if I'm not mistaken. Possibly Boss 302's did too. Mustangs with 289/302 engines (with the exception of the Boss 302, Shelbys and I've been told K code 289's) all got 8" rearends. 6 cylinder cars got the 7 3/4" ones.

Edited November 27, 2012 by maxum96

[cobra3073 24]

Only the big block cars got 31 spline axles if I'm not mistaken. Possibly Boss 302's did too. Mustangs with 289/302 engines (with the exception of the Boss 302 and Shelbys) all got 8" rearends. 6 cylinder cars got the 7 3/4" ones.

According to "The Hollander", the 1969 Mustangs with 302 engines could have either the 8" or the 7 3/4" diameter ring gears.

 

It is pretty well accepted that "during the day", Ford routinely utilized "mis-matched" parts on the line, when necessary.

 

I would be curious as to what Members on the Site originally had in their "regular" 1969 302 based Mustangs for ring gears.

 

Hope this is not off topic.

 

BT

[maxum96 32]

According to "The Hollander", the 1969 Mustangs with 302 engines could have either the 8" or the 7 3/4" diameter ring gears.

 

It is pretty well accepted that "during the day", Ford routinely utilized "mis-matched" parts on the line, when necessary.

 

Not trying to be argumentative here. But in nearly 30 years of playing with vintage Mustangs and many many hours of junk yard scrounging, I have yet to ever see a factory V8 Mustang with a 7 3/4" rearend. Have you ever seen one? The only ones I've ever seen was where someone swapped a V8 into a 6 cylinder car. Just because it's in the Hollander exchange list doesn't make it so.

[cobra3073 24]

Not trying to be argumentative here. But in nearly 30 years of playing with vintage Mustangs and many many hours of junk yard scrounging, I have yet to ever see a factory V8 Mustang with a 7 3/4" rearend. Have you ever seen one? The only ones I've ever seen was where someone swapped a V8 into a 6 cylinder car. Just because it's in the Hollander exchange list doesn't make it so.

...and I ABSOLUTELY believe you as it relates to your inference that "The Hollander" is not necessarily correct.

 

Yes, I too have spent a LOT of time in the junk yards (hence the reference to Hollander) searching for the "gold." I also confess that in my nearly 40 years of swapping out Ford engines, rear ends and transmissions, I have not concentrated on the small block stuff (other than the Clevelands) so I have never even CHECKED a "regular" 302 Mustang rear end.

 

I, too, am not trying to be "argumentative" but was just curious...still am.

 

BT

[1969vert 55]

Some of the 250 six cyl came with 8" also ..5 lug..

[maxum96 32]

Some of the 250 six cyl came with 8" also ..5 lug..

 

That I have seen. I think that was starting in 1969 or 70. But I wouldn't swear to it.

[etel64 10]

63C B5 3A 26B 16 6 X

BODY CLR TRIM DATE DSO AXLE TRANS

 

 

Thanks Cobra, I deciphered this as a 3:00 axle.

 

What does one mean by "provider"?????

 

I am hoping to just replace the center section and not the axles. the housing is all done and clean, installed and running.

 

What was with the 7.75 ring confusion ? Is there a 8.75 ring and a 9"?

[cobra3073 24]

63C B5 3A 26B 16 6 X

BODY CLR TRIM DATE DSO AXLE TRANS

 

 

Thanks Cobra, I deciphered this as a 3:00 axle.

 

What does one mean by "provider"?????

 

I am hoping to just replace the center section and not the axles. the housing is all done and clean, installed and running.

 

What was with the 7.75 ring confusion ? Is there a 8.75 ring and a 9"?

Yes, you are correct in your deciphering of the gear ratio.

 

Provider has to do with the aftermarket companies such as Currie, Strange, etc. Here is a link to a company that carries the 8" carrier (center section) as a complete unit. You should be able to utilize your current housing and axles.

 

http://www.justrearends.com/

 

Yes, there is an 8" and a 9" rear end. Both 8" and 9" rears could come with the same number of splines on the axles (28) while the 31 spline axles are found only on the 9", per the sources. For the '69 Mustangs, the 9" rear end was generally found on 351, 428 and 429 engines.

 

Generally speaking as it pertains to Mustangs, the 7 3/4" rear end came on those built with the six cylinder engine.

 

Our external discussion on this thread had to do with whether or not some 302 engines (which usually came with an 8") might have come with a 7 3/4" inch ring gear. I am sorry if this somewhat "off-topic" discussion may have caused confusion.

 

 

BT