U-joint phasing

[cranetruck]

Found this in the TM 9-2320-209-20 (1965). The u-joints are not phased correctly.

 

[moreorles2]

Bjorn- if your intention was to make us think- it worked. I did a Google search and came up with the following education about U-joints.

http://www.custompistols.com/cars/articles/ts_ujoints.htm

Bottom line is that one again you are correct- the fixed yokes must be parallel and they are not in the TM photo that you provided.

 

[Recovry4x4]

Yes, the evil phasing gremlins. Gotta watch out for them.

 

[jodka]

The caption says "Earth borer drive shaft and universal joints." Is it is ok to rotate an earth borer at non-constant speed? If so, then then the phasing as pictured would be correct.

- Allen

 

[emmado22]

Anyone got real life pics of a M35A2 with correctly phased joints so not so smart guys like me can check?

 

[willysmd]

Good call, you learn something everyday on here

 

[cranetruck]

I suspect that if little or no flexing is involved, the phasing is less important.

The drive shaft on the xm757 from the transmission to the transfer case is phased incorrectly and must have been so for years.

A formula showing vibrations as a function of the angle can probably easily be found.

 

[FSBruva]

Bjorn -

As an aside - it's obvious you are taking your time to do the XM757 right. It looks great!

Matt

 

[cranetruck]

Thanks Matt.
It's kind of like building a house and living in it before it's finished....you get used to the unfinished parts and the house never gets finished.
I'm trying not to jump ahead and start driving the thing before it's finished, so I keep it on blocks...he he he.

 

[SierraHotel]

I will have to check this weekend, but as I recall, the ends of the U-joints between the transmission and transfer case are slightly rectangular, making it so that you cannot get them out of phase. Kind of threw me at first because they look square. I never considered phasing. Thanks Bjorn..!

 

[jodka]

Bjorn wrote:

A formula showing vibrations as a function of the angle can probably easily be found.

A plot of that function is shown here in the Wikipedia u-joint article. The article also contains the formula.

The plot is reproduced here:

 

[jodka]

With reference to the above plot: it still seems that while pulsing the drive wheels through an incorrectly phased ujoint pair would vibrate the entire truck, pulsing an earth borer through an "incorrectly" phased ujoint pair might be harmless, and thus any phasing for that particular application would not in fact be incorrect.

- Allen

 

[rizzo]

I had to take the inter axle shaft apart on my M108 and the splines have one larger spline so that it can only be put together the one way

 

[FSBruva]

rizzo-

Is it the correct way? Just curious how widespread the military's "phasing" issues extend - saw three pictures in a 5-ton parts manual that demonstrated incorrect phasing. I think it was the -34P?

Matt