I was told that several years ago those axels were a little short and would twist the splines under hard load. I have them in a 8 3/4 with green bearings. It’s time to put that rear end to use and then I heard that. A search didn’t turn up anything.
Anyone ever heard of this?

Well, you could measure them and relieve all doubt.

Assume nothing. I would check. All doubt will be removed & you'll be able to move onto the next problem.

Hate to take it apart again but guess that would be the best bet.

I got Dutchman axles from Cass (DRDIFF). He use to sell Yukon. They fit dead on

The only reason they would cut them a hair short is if you are running the green bearings, they do not use the adjuster to set the end play. If the thrust button is still in the carrier it could cause the axles not to seat correctly. I doubt it will even be an issue with the splines unless they are really shortened.

A longer axle will twist the splines sooner than a shorter axle will, correct

Less spline engagement will twist before greater spline engagement, which is the question.

Put a custom 9" 31 spline Dutchman in the chev truck in the pic.. Best thing I did to it....

"I was told"

The three most dangerous words.

Since Randy has been around quite a few years, and this is the FIRST time I have ever heard that complaint, I would classify it as pure horse potty.
The other comments above have some value, if you decide to measure the axle. As it's out of the car, it would seem to be the time to do it.

Mark Williams has an interesting page concerning axles. It's worth a read. https://www.markwilliams.com/

The comment that longer splines weaken the axle is a MW selling point. The example is a low cost axle manufacturer that buys blanks with extra length, then puts several inches of splines on the axles, creating a universal part. When you order an axle, the universal axle gets pulled off the shelf and cut to length, most times leaving an inch or two of extra splines. The splined shaft has a smaller effective diameter and the axle would normally twist/fail in that section. If the splines are the right length but just machined where they are needed and nothing more is done to the shaft, the axle tends to twist off at the end of spline engagement. The right way to do it is to taper the shaft diameter down to the minor diameter of the splined area. Then there are no stress concentrators.

I believe that the axle will develop maximum strength when spline engagement equals the shaft diameter.

R.

so I did order my green bearing and Yukon’s from Randy’s but was never asked what bearing I was using. Also I am using a 742 diff. Assembly was not a problem and got no info on elimating the thrust button.
More searching and I found a couple posts on BB Dart.com on this subject, old ones but may still pertain. They mention twisting off the end of the Yukon’s.

http://www.bigblockdart.com/forum/showth...Yukon#post58452


http://www.bigblockdart.com/forum/showth...Yukon#post35744

I need to cipher all this out to see what the heck I have to do if anything. Might just call Randys after I dis assemble and measure axel length.
I vaguely remember hearing about this but thought I’d ask.

I've twisted off three stock A body 8 3/4 axles drag racing, all of them twisted off at the end of the splines closes to the wheels
On your deal you could use some wheel bearing or thick chassis grease on the splines and then reinstall the axle to see how far the splines are engaging into the posi unit or spool
All the stock Mopar axles have rolled splines on them, not machined like some of the better after market Hi Po axles
A friend of mine twisted the end off of one of Mark Williams 30 spline 8 3/4 axles, it had been in a stick shift 340 Demon for a lot of runs, he had removed it and saw the left axle splines where twisted about 1 1/2 spline from original
I told him to swap the axles form side to side It broke off 3 to 5 runs later in his E/SA automatic Demon, that axle shatter on that end between the splines and the other axle end, it did not twist off
I thought all Mark Williams race axles had a life time warrenty so I told him to call them, he did and they said it was 10 yrs at that time, not lifetime any more
They also told him to NEVER reverse or swap the axles from side to side after one run
He bought a cheaper set, maybe Mosers or Currys, and never broke another one
On your deal I wouldn't worry very much about it unless your going to race it a lot at the track with good slicks and lots of traction