andyh
2015 Tourist
Posts: 953
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Post by andyh on Mar 17, 2018 6:53:29 GMT 10
Lots of comment about Phasing on other forums but not much here. So the question is - Is it necessary in the 2014+ models? If so what is the correct alignment? 
Drive tines aligned with FD side of U-Joint ?  Or aligned with spline side of U-Joint? Interesting that there is no witness mark - and I didn't think to put one on  |
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Post by brucek on Mar 17, 2018 14:31:18 GMT 10
Lots of comment about Phasing on other forums but not much here. So the question is - Is it necessary in the 2014+ models? If so what is the correct alignment?
Drive tines aligned with FD side of U-Joint ? Andy, in line with final drive uni-joint is correct. At this position the final drive uni-joint and donut end are near enough parallel to each other. You may notice when you try and assemble 90° the other way the yoke uni-joint and donut end are not exactly parallel. The yoke and driveshaft splines are cut this way so there is only one correct way to go (two actually - you can be 180° out and still be ok). I found this recently when I had mine apart on the bench. Assembling to a different spline tooth each time will show only two places where things are in line (parallel to the F/D as I said already or 90° to the yoke joint). Any where else is not quite right - you can't assemble one or two spline teeth out for instance, it will be obviously wrong. Confusing? See the piccy.  |
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andyh
2015 Tourist
Posts: 953
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Post by andyh on Mar 17, 2018 15:26:08 GMT 10
Not confusing, pretty good description actually.
I must have tried every combination except the right one, as I couldn't get the splines to line up with the drive tines on the shaft.
I must have had my eye in when I replaced the FD. I got the orientation right and it aligns correctly.
Been for a test run and it seems ok.
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Post by brucek on Mar 17, 2018 18:02:33 GMT 10
Not confusing, pretty good description actually. I must have tried every combination except the right one, as I couldn't get the splines to line up with the drive tines on the shaft. I must have had my eye in when I replaced the FD. I got the orientation right and it aligns correctly. Been for a test run and it seems ok. That's good. As I said I had my F/D & driveshaft on the bench which made it easy to play with and 'eyeball' for correct alignment. Have a look at this Youtube clip. Illustrates the importance of correct phasing and the consequences of when it's wrong. Rotational speed at the driving end may be constant but the driven end is speeding up and slowing down. |
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andyh
2015 Tourist
Posts: 953
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Post by andyh on Mar 17, 2018 19:38:04 GMT 10
Thanks brucek, I had already seen that, what I was trying to get my head around was how did the donut end align. There were a couple of other videos from a while back, but I couldn't find one that showed the FD, shaft and donut all together. Oh and I will see how hot my FD gets tomorrow.
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Post by Uralee on Mar 18, 2018 8:32:36 GMT 10
Some shaft’s, like mine, will not align perfectly in phase no matter what spline you select. Near enough is good enough as Ural has only one Hookes joint and the slightly flexible donut can absorb the very minor speed changes.
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Post by brucek on Mar 18, 2018 10:07:36 GMT 10
Some shaft’s, like mine, will not align perfectly in phase no matter what spline you select. Near enough is good enough as Ural has only one Hookes joint and the slightly flexible donut can absorb the very minor speed changes. Agreed. I found mine was the same. At the correct 'in-phase' position it didn't look 100% correct but something you just have to live with. Any other position was plainly wrong. With all things like this there are manufacturing limits on the radial location of the splines of both mating parts when they are broached or hobbed and an adverse tolerance stack up on assembly can leave you with minor discrepancies that are (hopefully) still within practical limits. |
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Post by wilmo on May 7, 2020 10:05:26 GMT 10
It would be good to sticky this on the front page of Mechanical Questions and answers, useful info!
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Post by wilmo on Feb 3, 2021 18:22:36 GMT 10
The USA IMZ URAL site video here contradicts what is said above about aligning the drive tines with the FD side. From 10:15
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Post by Uralee on Feb 3, 2021 18:42:31 GMT 10
No contradiction there....... David has both yoke ends of the driveshaft “vertical”. That is phased.
The pinion yoke is horizontal....don’t be confused by that.
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