RCV Performance 930 CV plunging axle

[stress]

The drive flange is not damaged, the drive flange only has enough room to handle the plunge in the CV that is why I clipped the axle to the CV at the drive flange. The CV has 1.25 inches plunge at the CV.

The mid-board as a cup shape cover so the end of the axle is 4.75 inches away from the end of the mid-board hub cover. There are not hit marks on the cover.

The axle has 3.0 inches of plunge from short distance to full drop. Each CV only as 1.25 inches of plunge so I need 0.6-0.7 axle plunge through the CV inter race. If I clipped the axle to the CV at the mid-board hub I would not have enough plunge.

The thing that is controlling short distance side to side free play I measured is the CV at the drive flange only has 1.25 of plunge and since the axle is clipped to this CV. So the axle can not move that CV plunge at the drive flange.
Its not like micro-stubs where you have something the axle can hit on the backside of the CV. So mid-board numbers are not going to look like the normal numbers you see on micro-stubs.

RCV looked at the axle with a digital magnifying tool and said the CV inter race was grinding up the axle spline and caused the inter race to dig into the axle which was putting a axial load on the axle which caused the failure. They said they have seen this before.

What I take away from this experience and talking to RCV is I should not of set up my axles planning on the axle spline being able to plunge through the inter race on the CVs. I should of had the axles built so the axle splines are only wide enough to trap the CV inter races with clips so the axle can not plunge through CV inter races on both ends of the axle. So all my plunge would be handled by only the CV joint , there is only 1.25 plunge in each CV joint. I would have had to remove about 4.5 inches of suspension travel out my rear if I only have 2.5 inches of total plunge. If I would have done this I most likely would not have axle breaking problems. Trying to plunge 0.5 inch of axle spline through the inter CV race is the problem, I was thinking that mid-boards are designed to do this, but it causes problems. If the new plunging axles I got do not work out this is what going do next.

[arrowhead]

I machined the 930 star .375 deep so my spiralocks will slide inside the cvs on both ends

[Buggy Builder]

The axle has 3.0 inches of plunge from short distance to full drop. Each CV only as 1.25 inches of plunge so I need 0.6-0.7 axle plunge through the CV inter race. If I clipped the axle to the CV at the mid-board hub I would not have enough plunge.

.

This is your problem.

You designed your suspension so the spline MUST slide thru the CV joint.

RCV told you their shaft failed because there was excessive sliding between the shaft and CV.

[bdkw1]

Every trailing arm buggy out there has the axle plunging in the star. This should not be an issue. Polishing the splines on both the axle and star goes a long way. With the axle body the same diameter as the splines, the splines will want to twist before the axle body. This will lock up the star on the axle.

[nofearmxer]

I have these same axles on a buggy. Glad to know this.

BTW, RCV is the worlds worst company to deal with. I had a guy yelling at me on the phone. All I wanted was replacement CVs for the custom axle they built. Instead they told me they couldn't, and wouldn't help me because they are not experts on every axle and have no way of knowing what CVs I have. THEY MADE THE AXLES AND CVS! I also gave them the CAD drawing of the axle, THEIR OWN CAD DRAWING! I also paid for next day air shipping. 3 days later I call and they forgot to enter the order into the system somehow, that's what i was told anyways. Then they sent me the wrong CVS! So I call them and they get mad at me for calling them so much. WORST COMPANY EVER!

Anyways, their "reason" for why this failed made absolutely no sense, like the reply above, all trailing arms have plunge and the axle sliding through the CV star. What happened to their No Questions Asked axle and CV replacement policy?