Contemporary Cobra Watts Linkage

PDUB · #1 (**permalink**) 08-18-2010, 12:35 AM

Thanks for the info Daze... the newer stub axle looks pretty whimpy

! Is it up to high HP applications? Looks like they changed the splines on it... or am I missing something? I'll send a PM for more info. Thanks again.

cobrarkc · #2 (**permalink**) 08-18-2010, 06:56 AM

Quote:

Originally Posted by PDUB

Thanks for the info Daze... the newer stub axle looks pretty whimpy

! Is it up to high HP applications? Looks like they changed the splines on it... or am I missing something? I'll send a PM for more info. Thanks again.

You can still use the old stub axle by using a combiation u-joint. 1410 to 1350 and don't worry about the smaller 1350 u-joint they can handle up to 1000hp. This is where i got mine, even though they don't have it listed, ask them they have them.
http://www.dennysdriveshaft.com/c130...al_joints.html
Most u-joint places can get them for you.

Dazecars · #3 (**permalink**) 08-18-2010, 10:19 AM

Quote:

Originally Posted by PDUB

Thanks for the info Daze... the newer stub axle looks pretty whimpy

! Is it up to high HP applications? Looks like they changed the splines on it... or am I missing something? I'll send a PM for more info. Thanks again.

If you look at the two stub axles, old and new, the splined sections are about the same diameter, and that is where the torque is transferred to the wheel flange. With that in mind the newer stub axles have more splines which should make them stronger than the older Jag stubs.... make sense??

PDUB · #4 (**permalink**) 08-21-2010, 01:21 AM

Quote:

Originally Posted by Dazecars

If you look at the two stub axles, old and new, the splined sections are about the same diameter, and that is where the torque is transferred to the wheel flange. With that in mind the newer stub axles have more splines which should make them stronger than the older Jag stubs.... make sense??

The new splined section looks much sorter, and the splines look like they might strip out with any sort of wear, i.e. the surface area in which they mate to the hub looks whimpier. The old one looks like the input shaft on a toploader... that is pretty tough!

I'm not an ME, so I cannot say for sure, but it just looks weaker to me. I would love to hear from an expert, since I am interested in persuing the outboard brakes...

Cobrarkc, did you go with the outboard system?

Dazecars · #5 (**permalink**) 08-21-2010, 09:30 AM

I too am not a ME. I am sure the shorter splined section will reduce strength, but as fas as the splines them selves, lots of fine splines will always be way stronger than fewer heavy ones. its like a fine thread bolt vrs a course thread bolt, or a 19 spline axle vrs a 30 spline axle.

Ralphy · #6 (**permalink**) 08-21-2010, 10:04 AM

Quote:

Originally Posted by Dazecars

I too am not a ME. I am sure the shorter splined section will reduce strength, but as fas as the splines them selves, lots of fine splines will always be way stronger than fewer heavy ones. its like a fine thread bolt vrs a course thread bolt, or a 19 spline axle vrs a 30 spline axle.

I did the math once years ago on a fine vs. course thread. Thinking the surface area was maybe close to the same in area. However because the surface or depth was less. The solid section of the bolt minus the thread is greater making the area stronger. Plus resists backing off better. A fine threaded bolt is better, unless it is in an area where the nut is continually taken on and off.

PDUB · #7 (**permalink**) 08-22-2010, 01:55 AM

Quote:

Originally Posted by Ralphy

A fine threaded bolt is better, unless it is in an area where the nut is continually taken on and off.

Is this due to wear? Does that mean the smaller spline would be more likely to wear faster with the fore and aft torque of the drive line?

Ralphy · #8 (**permalink**) 08-22-2010, 05:30 PM

Quote:

Originally Posted by PDUB

Is this due to wear? Does that mean the smaller spline would be more likely to wear faster with the fore and aft torque of the drive line?

PDUB, We use a lot of fixtures at work. What I have seen is a chance of pulling threads out with continual use, bolt in bolt out. A splined shaft has a large surface area vs. fasteners I would not think you would see wear on a shaft vs. a bolt. I would not worry.

Helicoils work even better!

cobrarkc · #9 (**permalink**) 08-23-2010, 08:09 AM

Quote:

Originally Posted by PDUB

The new splined section looks much sorter, and the splines look like they might strip out with any sort of wear, i.e. the surface area in which they mate to the hub looks whimpier. The old one looks like the input shaft on a toploader... that is pretty tough!

I'm not an ME, so I cannot say for sure, but it just looks weaker to me. I would love to hear from an expert, since I am interested in persuing the outboard brakes...

Cobrarkc, did you go with the outboard system?

I am not an ME either but here goes. Think about a Ford 9" rear axle there are either 28 spline or 31 spline with the later being stronger. Now think about how much of the axle is splined, around the same amount that is splined on the newer Jag axle stub. The part after the splined area the is necked down only holds the axle stub into the hub and doesn't need to be as thick.