Topic: 69-70 Mustang 9 inch Rearend question

[70Twister]

Did they only make a 9 inch Traction-lok 3.50 gears with 31 splines only? Was any of the small block cars made with 28 splines with the same stuff?
I also need help with this rearend tag I can find it in my books :
        S319D
3L50   9   5B05

[ClevelandKid]

Heres some differential info.  3L50 means 3:50 Traction Lok. Most Traction Lok rears came with 31 spline axles.

http://www.mustangtek.com/differential/Differential.htm

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

[J_Speegle]

Looks like the tag and the third member is from a different time period (not the classic period we normally deal with) since the first line is not follow the W code pattern we normally see. Date code appears to back up the same issue.

Ford books show a number of applications where they built 3.50Ls with 28 spline but we don't know if this is one of them.

If its a loose third member you can count the spline - not an easy task. Or insert a 31 or 28 axle into the spline. If in a rear end - check the design on the end of the axle (at the brake drum) and report back or post a picture

[70Twister]

My 70 Twister Special calls for a 3.50 Traction-loK axle and has a S code on the door tag. I'm trying to see if its the right rearend still in the car it has 28 spline axles!
The date code on it is hard to read: ?D8 Has a C7AW E case.
 The tag in the question is a extra rearend I have. I was just wondering about what it is?

[J_Speegle]

My 70 Twister Special calls for a 3.50 Traction-loK axle and has a S code on the door tag. I'm trying to see if its the right rearend still in the car it has 28 spline axles!
The date code on it is hard to read: ?D8 Has a C7AW E case.

The date code and case number will not help you in this situation

Lets try this - If you can remove a wheel or hubcap to look at the center of the axle behind the wheel - which of the following do you see at the end of the axle (either side)? Your just looking for the round center section that will stick through the rear brake drum


A



B

[70Twister]

Mine is the "A" picture!

[J_Speegle]

Mine is the "A" picture!

Then the axle is a 28 spline given the housing its in and the car year

[70Twister]

Thanks Jeff!
When I removed the rearend from the car it look like it had never been removed before.
I just wanted to make sure it was the right one before I rebuilt it and put my NOS parts in it!
Any markings I need to put back on it? Dearborn car Oct. 1969