Rear end 8" or 9"

David Fulford · 01-17-2001, 04:58 PM

I have a 69 fast back that the axle housing has a hair line crack in. It is right in front of where the springs rest on the housing. Would welding it be a temporary fix until I can find a used housing. Also is there an easy way to tell if it is an 8" or 9" rear end and what number of splines the axles have.
Any suggestions on where to look for a used housing would be appreciated.

Tom351 · 01-17-2001, 05:14 PM

Someone correct me if I am wrong, but I am pretty sure that an 9" has a bulge on the rear side of it from the ring gear, while the 8" does not.

------------------
67 Fastback - Arctic White Pearl paint
351W ,Trick Flow Aluminum Heads, Edelbrock TorkerII, Comp. Cam, Performance Automatic C-4 Trans, 3.55 gears, Front Disc Brakes, 1-1/8" Fr. 3/4" rear sway bars.

My 351W Fastback

Gearhead999 · 01-17-2001, 09:46 PM

Quick way to tell a 8" from a 9". If you can take all the pumpkin nuts off with a deep socket it is an 8". You have to use an open end wrench for the bottom nut on a 9".

Dave

Clark Rodgers · 01-18-2001, 09:39 AM

Well David, it looks like they gave you all the right things to look for to determine if it's a 9in. The way you determine the splines is look at the end of the axle where your lugs are. The center area will be solid if it's 31 and it will be recessed in if it's a 28.
Welding the crack will work but I would replace it as soon as possible.

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69 351W Sportsroof deluxe

David Fulford · 01-18-2001, 10:03 AM

Well Gentlemen, once again you are all life savers. Appreciate the help.

01-17-2001, 04:58 PM	#1
David Fulford Registered Member Join Date: Oct 2000 Location: Charlotte NC Posts: 193	Rear end 8" or 9" I have a 69 fast back that the axle housing has a hair line crack in. It is right in front of where the springs rest on the housing. Would welding it be a temporary fix until I can find a used housing. Also is there an easy way to tell if it is an 8" or 9" rear end and what number of splines the axles have. Any suggestions on where to look for a used housing would be appreciated.

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01-17-2001, 05:14 PM	#2
Tom351 Registered Member Join Date: Oct 2000 Location: Atlanta,GA,USA Posts: 278	Someone correct me if I am wrong, but I am pretty sure that an 9" has a bulge on the rear side of it from the ring gear, while the 8" does not. ------------------ 67 Fastback - Arctic White Pearl paint 351W ,Trick Flow Aluminum Heads, Edelbrock TorkerII, Comp. Cam, Performance Automatic C-4 Trans, 3.55 gears, Front Disc Brakes, 1-1/8" Fr. 3/4" rear sway bars. My 351W Fastback

01-17-2001, 09:46 PM	#3
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Quick way to tell a 8" from a 9". If you can take all the pumpkin nuts off with a deep socket it is an 8". You have to use an open end wrench for the bottom nut on a 9". Dave

01-18-2001, 09:39 AM	#4
Clark Rodgers Registered Member Join Date: May 1999 Location: Rowlett,Texas Posts: 306	Well David, it looks like they gave you all the right things to look for to determine if it's a 9in. The way you determine the splines is look at the end of the axle where your lugs are. The center area will be solid if it's 31 and it will be recessed in if it's a 28. Welding the crack will work but I would replace it as soon as possible. ------------------ 69 351W Sportsroof deluxe

01-18-2001, 10:03 AM	#5
David Fulford Registered Member Join Date: Oct 2000 Location: Charlotte NC Posts: 193	Well Gentlemen, once again you are all life savers. Appreciate the help.