News:

SAAC Member Badges are NOW available. Make your request through saac.memberlodge.com to validate membership.

Main Menu

1968 GT350 Axle Spline count

Started by Corey Bowcutt, February 14, 2018, 06:19:01 PM

Previous topic - Next topic

gt350shelb

Some where some one is driving their collector car for the last time but they don't know it . Drive your car every time like it could be the last memory of it .

gt350hr

   Paul Bartus , as quoted on Kevin's site page is wrong about the "magnesium" being added to grey iron to make it "nodular. The material added was/is manganese. Big difference.
    Also ALL 9" equalocks were 28 spline . Never 31 that was a traction lock only. Pre '68 31 spline "locking axle" cars were Detroit lockers.
   Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.

Bob Gaines

Quote from: gt350hr on February 19, 2018, 01:18:10 PM
   Paul Bartus , as quoted on Kevin's site page is wrong about the "magnesium" being added to grey iron to make it "nodular. The material added was/is manganese. Big difference.
    Also ALL 9" equalocks were 28 spline . Never 31 that was a traction lock only. Pre '68 31 spline "locking axle" cars were Detroit lockers.
   Randy
Randy's page is more accurate then Kevin's page  8) .
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

Corey Bowcutt

I did get a chance to Check out my axles and gear ratios this past weekend and I do in fact have 31 spline axles noted by the 3 counter bored holes in the end of the axle.  I also rotated my drive shaft and counted the # of turns for 1 rotation of the tire and it is in fact a 3.50:1 ratio.  I also noticed that I appear to have posi traction.  I say this because when rotating the drive shaft both tires rotate in the same direction.  Also when I rotated one tire the other rotated as well in the same direction.  Does this indicate posi traction?  If so did they come with posi traction?

gt350hr

   Corey ,
      Ford called it "Traction Loc" and it was an option.  If your tag says 3L89 , then you r diff was originally equipped with one. It would also show on the Marti report. If not , they are often added to improve traction. It is also interesting that  GT350s  got 3.89 gears not 3.91s  which were "new for '68".
     Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.

shelbydoug

There was also something about a three disc and a five disc limited slip.

I don't remember the details but it might have been equal-lok vs. traction-lok?
68 GT350 Lives Matter!

gt350hr

   Doug ,
     That applied to Equalocks only which as I said were all 28 spline. The clutches were not "torque sensitive" like the later traction locks are. initially they had four steels and three frictions with 2 "Bellville" springs ( conical ) for clutch pressure. later units had 5 steels and four frictions with one Bellville spring. Traction locks have 4-1/2 "friction discs" and steel plates as one steel plate has friction material on one side. The traction lock design uses the "wedge action" of the spider gears to increase the load placed on the clutch pack , hence the name.
Celebrating 46 years of drag racing 6S477 and no end in sight.

shelbydoug

Quote from: gt350hr on February 22, 2018, 10:40:54 AM
   Doug ,
     That applied to Equalocks only which as I said were all 28 spline. The clutches were not "torque sensitive" like the later traction locks are. initially they had four steels and three frictions with 2 "Bellville" springs ( conical ) for clutch pressure. later units had 5 steels and four frictions with one Bellville spring. Traction locks have 4-1/2 "friction discs" and steel plates as one steel plate has friction material on one side. The traction lock design uses the "wedge action" of the spider gears to increase the load placed on the clutch pack , hence the name.

Aren't those clutch plates sourced from the C4 automatic transmissions as well?

I bought my first one over the counter in 1972 from my Ford Parts guy.

I had taken in an 9"-3.50 with an Equal lock, a "N" housing and 31 spline axles from, a 69 casting date, from of all people, a Ford Factory rep. I think he's the guy that wanted the 4.44 Detroit locker? I think I made about $150 on the deal?

That Equa lok started some discussion, not necessarily an argument. I remember the issue was it was 3 disc's. Maybe it was 28 splines? Huh?

I was a 23 year old Architect and I'm not supposed to be getting greasy crawling around under these things so it wasn't a matter of what is supposed to exist, it was a matter of what was in front of me.

The Equa-lok got sold off for $50 just by itself. No one really wanted it. The Traction-lok's are nice units. Nice and quiet.

Not like the Detroit lockers. Gee-se. That one almost got me arrested and I was only going 10 miles an hour IF EVEN THAT!
68 GT350 Lives Matter!

gt350hr

 No traction lock clutches are all by themselves despite being close in size to a C4.
Celebrating 46 years of drag racing 6S477 and no end in sight.

TXShelbyman

Quote from: shelbydoug on February 22, 2018, 01:52:35 PM

Not like the Detroit lockers. Gee-se. That one almost got me arrested and I was only going 10 miles an hour IF EVEN THAT!

Now you're scaring me Doug. My car originally had a 3.00. Someone changed it to a 3.50 with a Detroit Locker. Tim sent me some info stating that my car had been in for warranty work on 7/6/68. Rear end rebuild including a new ring an pinion. I'm wondering if that is when they changed the gear out. Not to derail the thread, but does anyone know why the build sheet shows two digits for the axle? My build sheet shows 76 but the axle code on the door tag is 6.
When things go bad just hit the throttle, may not solve the situation but does end the suspense.

Formally watts428

jguyer

Quote from: Corey Bowcutt on February 19, 2018, 04:40:44 PM
I did get a chance to Check out my axles and gear ratios this past weekend and I do in fact have 31 spline axles noted by the 3 counter bored holes in the end of the axle.  I also rotated my drive shaft and counted the # of turns for 1 rotation of the tire and it is in fact a 3.50:1 ratio.  I also noticed that I appear to have posi traction.  I say this because when rotating the drive shaft both tires rotate in the same direction.  Also when I rotated one tire the other rotated as well in the same direction.  Does this indicate posi traction?  If so did they come with posi traction?
Do the 3 counter bored holes always mean it's 31 spline axle? Had a 77 Granada with axle of that type.
"Never trust a man that don't eat cornbread, or a woman that don't cook it"

shelbydoug

Quote from: TXShelbyman on February 22, 2018, 08:58:44 PM
Quote from: shelbydoug on February 22, 2018, 01:52:35 PM

Not like the Detroit lockers. Gee-se. That one almost got me arrested and I was only going 10 miles an hour IF EVEN THAT!

Now you're scaring me Doug. My car originally had a 3.00. Someone changed it to a 3.50 with a Detroit Locker. Tim sent me some info stating that my car had been in for warranty work on 7/6/68. Rear end rebuild including a new ring an pinion. I'm wondering if that is when they changed the gear out. Not to derail the thread, but does anyone know why the build sheet shows two digits for the axle? My build sheet shows 76 but the axle code on the door tag is 6.

The problem with the "law" with MY Detroit Locker was that on a left hand turn, it would lock the inside tire.
There was just a simple situation where there was a traffic light that crapped out and we had two "motorcycle" cops directing traffic.

At my turn at the light, the cop signaled to me to turn left. The car was idling at 800, I let the clutch out easy, just feathered the throttle as one normally would, and here goes the locker. It locks the tires and as I turn spins the tires and leaves rubber.

OK, I'm not going to call anyone names. Let's just project a scenario where I need to explain to the "motorcycle contingent in 'Dirty Harry'", exactly WTF "my problem is"? Not a comfortable scenario.

The Traction-lok was in the car by the next weekend.
68 GT350 Lives Matter!

gt350hr

Quote from: jguyer on February 22, 2018, 11:26:20 PM
Quote from: Corey Bowcutt on February 19, 2018, 04:40:44 PM
I did get a chance to Check out my axles and gear ratios this past weekend and I do in fact have 31 spline axles noted by the 3 counter bored holes in the end of the axle.  I also rotated my drive shaft and counted the # of turns for 1 rotation of the tire and it is in fact a 3.50:1 ratio.  I also noticed that I appear to have posi traction.  I say this because when rotating the drive shaft both tires rotate in the same direction.  Also when I rotated one tire the other rotated as well in the same direction.  Does this indicate posi traction?  If so did they come with posi traction?
Do the 3 counter bored holes always mean it's 31 spline axle? Had a 77 Granada with axle of that type.

    The three holes are there for machining operations. The "center" is a lathe center and the outer two are holes for a "driver" for the spline operation and some turning. While this "precision method" was used for 31 spline axles , it is not unique to them. '60s axles had the three holes and were 28 spline. ALL 31 spline "performance axles" did have the three holes through '73. The process was also used on 28 spline axles from '72 forward on some vehicles.
Celebrating 46 years of drag racing 6S477 and no end in sight.

jguyer

gt350hr, thank you for the explanation.
"Never trust a man that don't eat cornbread, or a woman that don't cook it"