half shafts

[mike_starling]

Guys,

Will need to acquire half shafts some time in the near future. What I don't know about them is legion.

Need to go from a G50-52 to Corvette hubs. The original vendor of my kit used a 14" slip shaft with U's at both ends. An adapter plate had to be made from the gear box flange to the flange on the inboard U. I can't locate the maker of the slip shaft he recommended (Marc Industries) on the internet.

Engine will generate lots of power and torque. Strength will be an issue. (I remember when Ford broke more than a dozen half shafts on Mark IIs at Daytona one year.)

Anyone have the bolt circle information on the transaxle?

What material should be used for that adapter plate?

Where do I go to look for this kind of hardware?

What additional information am I going to need to order parts?

Thanks VERY much,

 

[Mark Worthington]

Mike, I would give Marty a call at Raxles. (888) 257-8192

He made some very nice, strong half shafts for my Mustang Cobra, which stood up to many 5,000 rpm clutch dumps with drag radials in a 3,500 pound car. He can make new half shafts for you with CVs or he could also make the required adapter plates should you choose to keep your U-joint setup.

There are probably other vendors out there who build custom half shafts. I know that GKN was building the OEM half shafts for the Mustang Cobras and they were making aftermarket pieces available. I'm not sure if they would do a one-off setup for you but it wouldn't hurt to ask.

 

[Mike Dozier]

Mike

Either copy Lynn's adapters or ask Peter @ DRB to sell
you a pair. I can send you the Spicer part numbers that
make up these half shafts if you like.
Or you can buy those from Peter also, but at a premium.

MikeD

 

[mike_starling]

MikeD,

I'd sure appreciate the parts list.

I can make the adapter if I had some idea of the material required. Bolt circle measurements would also be helpful, but can wait until I get the rest of the parts and then measure them.

Thanks!

 

[Ron Earp]

Mike, do you have the hubs and transmission? If so it would seem like any drive shaft shop could do this job. All they would have to do is fit a tube with u joints on either end and balance that assembly. Certainly a 1.5-1.75" steel tube would take whatever torque you coule put through it.

 

[Mike Dozier]

Ron

Have to have a slip joint somewhere in the assembly
to allow for suspension travel. The Corvettes have a slip
yoke with u-joint on the pumpkin...the transaxles we deal with do not.

Mike...I'll locate the list. The adapters I've seen are
made from steel bar...around 3/4" thick...some with a pierced
hole in the middle to reduce weight...others just solid.
Aluminum would be neat...but I'd be concerned over pulling
out the threads under heavy load.

MikeD

 

[Mike Dozier]

Mike

Here are the Spicer parts I bought:

(2) 3-2-119 Flange yoke
(2) 3-3-2591KX Slip yoke
(2) 2-40-1711 Tube shaft
(2) 3-28-47 Tube yoke
(4) 5-178X U-joints

These are found in Spicer's catalog J300P on their website
www.spicerdriveshaft.com
I paid $ 450 for the above, and still need to have them
welded together and balanced by my machine shop.
These parts go together with 2.50 " .083 " wall tubing,
and when finished look something like below.
Thanks to Dave Harris for the photo.

Check with Lynn on the length of the tubing needed per side.
My guess is around 7.00 ".
Regards

MikeD

 

[mike_starling]

Mike,

thank you!

Is going to save me LOTS of interesting challenge. It's hard to find this kind of info in Charleston, WV. Love the place, but it is just a bit "out of the way."

 

[BenL]

I like this document on the Spicer/Dana website: <u>Failure Analysis Guide</u> http://www2.dana.com/pdf/3272.PDF

 

[Mike Dozier]

Typical adapter...again thanks to Dave Harris.

MikeD

 

[Mike Dozier]

Another view

 

[Chris Duncan]

Have you considered CV axles? They are more spendy at about $1,500.

If you go that route here's what I'm doing on my G50, not sure if it's the same as the G50-52.

Inboard is a 108mm Lobro joint which bolts up to the G50. Outboard is another 108mm Lobro with a stub/flange adapter that fits in the C4 Vette hub splines and has a flange that bolts to the Lobro.

This setup is good to about 600 RWHP.

Another way to do it is with a '85-'89 Cad DeVille outer joint which fits in the C4 hub and then make a custom shaft with the Lobro spline on one end and the GM spline on the other. This is only good for 400 or so RWHP though.

The builder, Bret at www.markwilliams.com says there's another hub similar to the C4 vette that's the next diameter larger, like a Tbird? Says he can make a 1000 HP axle with that.

 

[Lynn Larsen]

I suppose this is as good a place as any to put this.

I had a brain fart last night when I reassembled my half shafts and looked at them wondering, "are those u-joints in phase?" I couldn't recall which way was the right way, but I knew that they needed to be right or they would vibrate.

So I looked it up on google and here is a diagram to use as a go by: