Prop shaft removal

[Bumble Beep]

Hi all.

I removed the front prop shaft for easier exhaust/oil pan removal and didn't add reference marks (as per the service manual). Why are these marks needed? Looks to me that it wouldn't matter if the u-joint was installed in the original position or rotated by 180 degrees. Do the u-joints at either end need to be in a certain configuration i.e. yokes inline or at 90 degrees from each other?

 

[Bumble Beep]

Just realized my second question is a stupid one! But still wondering about need for reference marks.

 

[Jerry Bransford]

No need for reference marks so long as you don't pull the driveshaft apart into its two halves.

 

[Bumble Beep]

Two halves? Do you mean disconnect what's under the boot (I assume a piston-type connection)?

 

[AndyG]

What you don't want is it out of phase....where the u joints are not aligned if you looked down the shaft like a rifle.

Separating the spline shaft and re assembly if not indexed could cause that.

As far as relationship to the vehicle as was installed , I'm not certain , but I know it isn't as critical as phase, as a shop sold me one built out of phase. It was insane.

 

[Jerry Bransford]

Two halves? Do you mean disconnect what's under the boot (I assume a piston-type connection)?

The boot just covers the driveshaft's splined slip joint which allows the driveshaft to compress/expand as needed. So long as you don't pull that apart there's no chance of getting the driveshaft out of phase. Pulling the driveshaft apart and putting it back together so the front/rear u-joints are no longer aligned with each other is what gets its front and rear u-joints out of phase with each other which causes vibrations.

If you don't pull the driveshaft apart into two pieces and reassemble them so their f/r u-joints are no longer in line (out of phase) with each other you won't have any problems.

 

[Bumble Beep]

Thanks for the explanation, makes sense now. Didn't realize there was a splined joint underneath. There's no need to pull apart, so no worries then.