Half Shafts

Just wondering where people get their halfshafts.  What we've done in the past is take a stock polaris halfshaft (assembled with CVs on it), cut it and then weld in an extension.  As you can imagine we have reliability issues with the halfshaft breaking at the weld.

We've thought of making a custom axle and using the the stock CVs but we have never been able to remove one of the CVs from the stock axle.  Is there a trick to taking a CV off?

At the moment I'm leaning toward using aftermarket CVs with a custom made axle.

Thanks.

We went the weld route and then switched because of reliability reasons.  We found someone local for us to mix and match halfshafts.  Try the www.cvman.com, he helped us put together as driveshaft that was the length we needed with OEM cv joints.  We had a honda outer joint, kawasaki inner, and a yamaha rhino axle.  The driveshaft was custom length and he was able to get it made for around $100 dollars.

Sorry here is the contact info

We have always made our own halfshafts, although we use u-joints.  It really isnt that hard to do and we only use 1.25" x 0.095" tubing for the shafts.  Also, chamfer the ends of the tubes before welding if you havent in the past in order to get more weld penetration.

We have done a lot of experimentation with half shafts for our Formula car.  This year in Baja we will be using the same methods


As far as the experimentation, we have tried the following:  straight cut the insert and shafts, chamfer and weld in a lathe.  In our Formula car, the axles lasted two laps.

We have tried to fishmouth the insert, then weld, and those axles lasted one launch. 

Last, and most successful, we cut the insert at a 45 degree angle, and then welded it in a lathe.  EVERY axle with this method has lasted indefinitely, and had no issues.  Our Formula car from last year has not shown any signs of fatigue or failure, and we have thoroughly thrashed that car.

All welding was TIG with ER70S-2 filler, and since we could not get the axles apart, there was no heat treatment.  The inserts up to this point have been 4130, but 4340 would be preferable.


The insert wall and OD is dependent on the axle OD's and the power the engine produces.  This year we will probably buy 4340 tubing and go with that. 

Originally posted by blue2kss Last, and most successful, we cut the insert at a 45 degree angle, and then welded it in a lathe.  EVERY axle with this method has lasted indefinitely, and had no issues.  Our Formula car from last year has not shown any signs of fatigue or failure, and we have thoroughly thrashed that car.

We gave this repair a try last night. Took it for a spin in the snow afterward and it didn't break immediately, so that's good. Once we get the car out to our test track we will be able to more thoroughly beat the crap out of it.

I'll let you know how it goes.

Quick update: After a 4-5 hour stint at our track, the 45° halfshaft is still going strong. We will probably go with this method for the new ones as well. It's significantly faster to fabricate. 

Here is a Solidworks Model of what we did. Cut it on a 45° angle, make an insert angled the same on both ends. Keep in mind it doesnt matter if they are misaligned along the axis, just that the angle is the same. I would use the same saw and do all the cuts at the same time. They dont have to be exactly 45, they just have to be the same. 45 just carries more load.

For this one we didnt even bother welding in the lathe. We just clamped it to a piece of angle iron and welded. Also, we chamfered all the edges to be welded using the bench grinder.

ER80S-D2

My initial plan was drill holes and put a pin to hold it true. But then I got lazy. No Pin, no key, no sleeve. Cut and Welded. So far so good. 

We managed to do it last year with Ranger IRS axles.  We used a slip fit piece of pipe over the driveshafts and welded the pipe on both ends.  Some teams cut the extensions at a 45* angle for more weld area, but instead of this we used 4 plug welds at each end.  Havent had a problem yet!

We actually just got done doing this yesterday.  We used the same rear end (outlaw IRS).  We used the 45 degree method as mentioned above.  We extended each half about 6 inches to give our desired track width.  Just take your time to get them trued up.  We clamped them in the angle to get them close with good tack welds.  Then put them back in the car and trued them up by marking the high points.  Some weld in the lathe and that works well also.  The diameter of the outlaw shaft is .940" if I remember correctly and we just bought a piece of 1" solid cold drawn (can't remember alloy) and turned it down to .940" to make it all line up good. 

Edited by racers.baja - 2010-Feb-02 at 11:20am

okay, sorry about that.