Question about u-joints and engine alignment.

[kyleputzier]

I've removed my engine to repair a rusted oil pan. As I prepare to put the engine back in, I wonder to myself if the square nuts that adjust and support the rear engine mounts have moved. I was wondering if that can affect the engine alignment and how would I correct it. I've decided that the vertical height is compensated by the double u-joint of the outdrive. Is that true?

On to my main question. I have heard that u-joints need to be out of alignment slightly in order to make the bearing needles move around. Otherwise the same needle(s) would be taking all of the torque all of the time and eventually fail. It appears that a properly installed outdrive would be nearly perfectly aligned with the engine and the u-joint bearings would not be exercised. Seems wrong to me. Opinions?

 

[Don S]

Re: Question about u-joints and engine alignment.

The alignment is for the coupler and the shaft going into the coupler. Has nothing to do with the ujoints at all.

Also think about what happens to the ujoints during turns and trimming up and down.

 

[kyleputzier]

Re: Question about u-joints and engine alignment.

Got it. Engine alignment has nothing to do with the outdrive. I has to do with aligning the shaft as it naturally fits into the coupler with the gimbal bearings position. Alignment makes perfect sense now that I think of it from the couplers view. I don't need to worry about the rear engine mounts unless the front engine mounts run out of adjustment.

 

[saintlee]

Re: Question about u-joints and engine alignment.

alignment between engine and Gimbel bearing should be as perfect as possible
noise, vibration, and premature wear of coupler/bearing will result

the double u-joints are aft of the bearing - they affect steering (left-right) and adjusting trim (up-down)
they should BOTH be checked at least once a year when you remove the outdrive