U-joint tech 101 -- failure analysis...

[Chris Pucci]

So I blew through 2 long side front axle shaft setups on the last run...

Now I need to build some more long sides from my parts pile.

In looking over the carnage in my pile I had a good long inner and a good outer. Few minutes later - broken ujoints are pounded out and I am ready to press in a new joint and be on my way -- when all of a sudden---- what the?!?%$#@@!!!!??

I realize that I have an inner axle shaft that is designed for the smaller 260-x -- of course it failed in my truck!! Duh!! Doh!! it only lasted about 150 yards at the most. I had even welded the caps in - so it wasn't a cap or clip failure it was a full breakage of the cross shaft...

Somewhere through my travels I must have picked up a pre-72 Chevy d44 that was still running the smaller 260-x u-joints. In my haste to always have a spare set of axle shafts I grabed them and tossed them on the pile...

Pics:

side by side of the 260-x cap and the 297-x cap... Can you pick the winner?

260-x cap @ 1.065"

297-x cap @ 1.195"

Carnage that you can achieve with the proper u-joint not holding you back :d (long side inner yoke):

 

[Binderbound]

Step out of the 90's chris. The big ones are 5-760x's now. I run the stock 5-760x spicers, with full circle snap rings, in my chromo shafts and have not had a failure yet. Of any sort. If they do, I'll go to longfield super joints.

 

[Chris Pucci]

step out of the 90's chris. The big ones are 5-760x's now. I run the stock 5-760x spicers, with full circle snap rings, in my chromo shafts and have not had a failure yet. Of any sort. If they do, I'll go to longfield super joints.

The 297 and 760 are technically the same size on the outside.... I use 760-x joints but for simplicity I just refered to them by there long know spicer #....

Your 760's survive more due to your light weight and low hp, than due to there 20-30% increase in strength ....

 

[SS2]

your 760's survive more due to your light weight and low hp, than due to there 20-30% increase in strength ....

I think this should be dans new moto..I can see it now on tractractor stickers. " tractractor-light weight & low horespower"