Skip to main content

Replies sorted oldest to newest

Spicer halfshafts were big when oem u-joints were an exhorbitant price, making the spicers a cheaper option than new u-joints. The oem halfshafts are rated for something like 700 HP and perfectly good for almost all but racing applications, making spicers an uneccesary upgrade IMO. In fact for anyone considering upgrading I'd recommend going to more modern CV axles. Sacoperformance is selling a CV axle upgrade for $1195 probably not much more than you have to pay for the old technology spicer halfshafts.

Find the CV's here at the bottom of the page...
http://www.sacoperformance.com/products.php?cat=14

Julian
quote:
Originally posted by Joules5: Spicer halfshafts were big when oem u-joints were an exhorbitant price, making the spicers a cheaper option than new u-joints. The oem halfshafts are rated for something like 700 HP and perfectly good for almost all but racing applications, making spicers an uneccesary upgrade IMO.


I totally agree Julian. There's nothing wrong with spicers but there's nothing wrong with the stockers either. Just have a look at the two side by side and you can see the stockers actually have favorable geometry for strength. In fact, some time ago, Dennis Quella told me that the Hill Climb guys there in Colorado had used the stock Pantera half shafts with great success for decades. Proper U-joints are now readily available for stockers and that was really the only issue.

quote:
In fact for anyone considering upgrading I'd recommend going to more modern CV axles.


Yes, and I am going that route, but I must admit it's more of a luxury than necessity, but dont think the conversion is going to save you a bunch of unsprung weight. -In most cases it won't. You may however pick up a percentage point or two improvement in getting your flywheel horsepower to the ground as they are more efficient than U-joints and at constant velocity, a better preformance and track option for cornering traction. -Pretty tough to argue you need that on a street machine. But hey, the lines are often blurred between need and want for me when it comes to my Pantera. The other thing to remember is CVs maintain (near) constant angular velocity through their usable deflection range whereas u-joints suffer as angular displacement increases through your suspension. Pantera's are pretty tame as far initial angular deflection and don't have much travel at all compared to off road vehicles so there is less to be gained is this respect.

quote:
Sacoperformance is selling a CV axle upgrade for $1195 probably not much more than you have to pay for the old technology spicer halfshafts.


That's not bad compared to what it would cost to spec the components yourself depending upon how you valued the cost of the adapters. I must say, I'm not a fan of the adapters. Just adds more weight and is a another set of critcally stressed fasteners and potential point of failure in your drive train. The real dough comes from sourcing proper CV stub axles for the ZF and companion flanges for the Pantera Rear uprights. I must advise however, even this approach wont save you appreciable unsprung weight. As an incidental benefit it may gain you a little more tail pipe clearance due to the smaller diameter axle.

quote:
Find the CV's here at the bottom of the page...
http://www.sacoperformance.com...cat=14


That site also has the rear uluminum uprights listed but "out of stock". I believe Ken Green was involved with the development. They are nicely done and use a modern packaged cartridge bearing and hub assembly. I was never able to confirm the total weight of this set up with Ken but the those packaged assemblies aren't especially light either but are convenient for replacement. I'd like to know the total weight. The stock rear Pantera upright weighs 14 lbs bare. You can save 6-8 lbs by re-engineering this piece with lighter materials and using stock components at the potential expense of some toughness and durability. I doubt you get that much out with the uprights and axles shown at that site, but I'd like to corrected if that is not the case. That CV package was originally conceived to go along with the upright package which at that time was being considered to be offered at $3300k. However, you still needed to address, hats, rotors, and rear calipers and mounts before you were done.

In for a penny in for a pound (sterling that is Big Grin)

Best,
Kelly
Last edited by panterror
We’ve discussed this numerous times before but it is worthwhile to repeat it again. Not all stock half Shafts can successfully have their U joints replaced. The problem is caused by a factory machining error in the yokes that were machined too large/incorrectly. From some of the examples I’ve seen it looks like the machined bore was not smooth so the U joint caps fit tightly when first installed at the factory and then over time worked on the yoke and become loose. In the case of my own half shafts some idiot tack welded some of the caps to the yoke. http://www.panteraplace.com/Te...e%20rebuild%2014.jpg Got to love the shade tree mechanics, especially the ones that have access to welding equipment!

The horrific damage a broken half shaft can cause to your car not counting killing you in crash far out weights the cost of a quality set of new half shafts. If you have ever seen a car damaged from a broken half shaft you all understand what I’m talking about. The ones that rip the side out of the ZF are pretty interesting too!

Mike
Last edited by pantera1887
Fair point Mike. Not sure how wide spread that problem was. Your car is a 71; right? If we wanted to start a list of the inconsistancies in Pantera production that could lead to hazard when increasing the performance envelop, it could turn into a very long discussion. Not sure that is just a problem limited to Panteras.

Though for the reasons you mention it can be a serious matter, IMO this issue is more a matter of proper maintenance than inferior design.

One that come to my mind is the stock stub axles in the rear uprights never had the proper interference fit with the ball bearing thus the ball bearing was never properly preloaded and worse yet, often resulted in fretting of the stub axle often leading to premature failure.

Many things depended upon how much Vino Luigi had for lunch. Smiler

But then again, this site is for celebrating the Marque. I'm planning on having mine for a Lonnnnnggggg time!

Take Care,
Kelly
I had a problem with the original half shafts in my '71. At 30k miles, the u-joint caps were rotating. I was heavy into preventative maintenance, so I knew that lubrication was not the issue.

Upon disassembly, I found plenty of grease and no flat spots on the trunnions or the needle bearings. What I did find was that all of the yoke bores were extremely rough. This was not caused by the u-joint caps slowly rotating, as some of the caps had not rotated. The yoke bores looked as though an extremely rough cut had been made with whatever "boring" device was used, and it was not followed by a finish cut. In this case, the "high spots" of the "rough cut" appeared to be approximately equal to the required final finished diameter. If a clean-up (or finish) cut had been made, the u-joint caps would have fallen through the bores.

I had to go over a few heads, but I got Ford to give me two new half shafts.

John
Last edited by jb1490
Sacoperformance rear Aluminum uprights weigh 10 lbs bare, but assembled weight (with bearings, hubs, etc.)is the same (within a pound) of a simuar equiped stock unit with the GT-5S units heavier. The kit retalis for $4995.00 and includes everything required except the Porsche 996 Turbo brake calipers. Their CV Joint Kit also comes in at the same weight as stock or Spicer half shafts. I can get you a set of their uprights bare ($2995.00), but no stock components will fit, and the kit saves over $1,200.00 for individual components.
Hustler,

I am having the SACO Performance entire kit installed on my '74. I was given a choice of CV boots on the axle. I obviously went with the best ones that they offered for heat resistance. Ike is the person to talk to about this -- he knows the ins and outs of any technical question you may have. And if he doesn't know, he will find out and get back to you.

Best of luck,

Mark
Post
×
×
×
×
Link copied to your clipboard.
×