Shaft alignment – questions for the pros

I needed to replace the rubber isolater bushings in the rear motor mounts this year. The old ones were hard as rocks and starting to breakdown. I was able to get the old bushings out and the new ones in without much trouble. I figured this is a good time to check the alignment. Prior to this, I have not had any issue with vibrations, but since I was changing the bushings and the alignment had not been checked in years, I figured it was time. I watched Pete’s video the checked the strut alignment and strut bearing and it looked straight and tight.

My question comes when re-connecting the coupler flanges.   When the flanges are separated about a ½ inch or so, prior to the collar in the rear flange connecting with the front flange the two flanges do not line up.    



When I line them up and move them closer to where the collar is lined up with the front flange, when I check the gap, it’s even all the way around. I rotated the flanges so they were in different positions and the gap always seemed to be consistent and even.



I don’t know if I was wasting my time, but with the flanges separated, I tried to get the flanges to line up by adjusting the mounts. For whatever reason, I could not get the motor to adjust from side to side. All the mounts moved freely and could be adjusted, but when trying to pry the motor to the side, it would not budge. I also made sure the loosen the bolts that allow the side to side adjustment. I loosened the mounts and was able to see the parts of the mounts that allow the side to side were free and not froze up.

I ended up reconnecting the coupler flanges and did not need to make any adjustments.

I’ve read some post that said it’s a good idea to remove the packing prior to performing the alignment, but I didn’t see that in Pete’s video. Also, I have not had the boat in the water yet this year, so could that have affected the alignment when the flanges are separated, or maybe when they are separated, it makes no difference at all.

If anyone has thoughts or advise, it would be appreciated.

Thanks,
Andy

Andy,
You haven't posted a picture of the log/hose/packing gland which would give a visual indication if the shaft is centered in the log. Remember alignment starts at the strut and then forward. The shaft needs to be roughly centered in the log and turn freely in the cutlass before you align the engine. Is it centered and still turns freely in the cutlass? The picture showing the shaft way off to port in relationship to the engine does tell me something is wrong. Continue investigating.

You say the coupling flanges are even between them. What is the difference if any? .003" is max side to side and top to bottom. What did you check the difference with?

Engine mounts can get real stuck. Some have even had to remove them one by one to free them up on the bench.

Vibrations are snubbed by misalignment. Vibration is NOT a good indicator of alignment.

One more question, should I remove the hose and packing gland to see how centered it is in the log or should I be able to determine that by how much side to side free play there is and if it's resting in the middle?.

Andy - You can put a small jack under the manifolds & hold up the rear of the engine while you remove the mounts to free them up.    Try using some ATF & acetone mixed 50/50 as a penetrating oil, it works great.

So, after a very rainy weekend, I was able to get to the bottom of the motor not moving right to left. On the port side mount, I loosened the pinch bolt and then removed the whole mount. I knew it was not binding in the mount and proof of that was the two pieces feel apart when I got them out. (The pinch bolt fell out too because I had completely removed the nut, but that's another story.) After examining the mount to try and find out why the motor was not moving and not finding anything, I tried to move the motor without the mount in place and it moved right over with a little leverage. I then looked at the area where the mount bolts to the motor, and you could see a slight wear mark were the end of the round rod was just slightly touching the block. So I went back to the mount, and with the round rod pushed all the way into the receiving part, the rod stuck out about 1/4 inch. I then went to the bench and removed the about 1/2 of an inch, re-installed the mount and was able to move the motor to line up with the shaft side of the coupler.   And yes, prior all this, I did re-confirm the strut seemed straight and the shaft was centered in the log.

This was all Friday night and I still had not found my feeler gauges. A ran to the auto part store in the morning and was able to following the instructions in the video. Up and down seemed good, but with some adjusting I was able to get the .007 on one side and .009 on the other, but not the .010 so that's were I left it. I figured that's between .002 and .003.    I was thinking I would run it a while and then re-check.. I store the boat on a hoist in the summer. Is there any problem doing the check on the hoist or even in the water?

due to the rain, I was not able to water test, so that will be in 2 weeks.   

One more question about the rear mounts. Why are they only mounted on the top and the lower holes are not utilized. They also seem to be mounted about 1/8 inch away from the cradle.   Seems odd, but I'm guessing there's a reason. .

Has anyone heard of the mount rod hitting the block? After I was all done, with a light, I could see through a small relief in the mount that it was not touching the block.

Andy