is this an alignment problem?

[peteua636]

Hello.<br /><br />I have alpha 1 Gen 2 drives. I changed the u-joints and when checking the alignment noticed that the grease lines "tracks" were not even all the way around the alignment tool on the starboard side. I adjusted the engine up in the front and made sure both sides had equal threads showing on the motor mounts. The drives went back on the boat extremly easy. Now when I am out on plane as the bow dips up and down I get a noticable pulsing vibration felt in the floor. <br /><br />Any ideas?? Is this the sign of the gimbal bearing starting to go bad?

 

[WillyBWright]

Re: is this an alignment problem?

It could be. It could be a harmonic, but I'd think you'd have noticed that before. Did you check the bearing while the drive was off?

 

[peteua636]

Re: is this an alignment problem?

Yes...Bearing seemed smooth and had no play front to back or side to side.

 

[Bondo]

Re: is this an alignment problem?

It appears you've got it pretty well lined up.....<br />Exposed threads on the bolts really don't mean much.... It amazes me that they Do equal each other...........<br /><br />What are your Props looking like ?????

 

[peteua636]

Re: is this an alignment problem?

The props are SS I have had them off and balanced. The Balance company says they were way out it seemed to make a bit of difference. I have also overhauled the gearcase-checking all shafts for straightness...nothing was bent. Then each componet of the gear case was balanced. I just cant seem to work this vibration out...

 

[BMDODGE]

Re: is this an alignment problem?

MOTOR MOUNTS ???

 

[peteua636]

Re: is this an alignment problem?

Mounts seem to be in good shape. Not sure how to actually check them but I didn't find anything missing broken or loose.

 

[Rhadley]

Re: is this an alignment problem?

Just to make sure; you did use the alignment tool to set the pitch of the engine and not the number of threads protruding from the mount, right? Seems somewhat suspicious that there was no vibration before you changed the engine position.

 

[peteua636]

Re: is this an alignment problem?

Yes....As stated above I adjusted the mounts due to the uneven grease tracks on the alignment tool. When this was completed there were even tracks around the tool.

 

[Bondo]

Re: is this an alignment problem?

How about your Engines ?????<br />Is it Possible you have a high-speed Skip ???

 

[peteua636]

Re: is this an alignment problem?

you mean like a timing issue ie a pickup coil failing?

 

[Bondo]

Re: is this an alignment problem?

Or a Fuel Delivery Issue.....

 

[peteua636]

Re: is this an alignment problem?

engines do not seem to break up or miss at all

 

[itstim]

Re: is this an alignment problem?

Today I tried to put my drive in and it wouldn't go. I checked the alignment and it was slightly off so I pulled the tool out slightly so I wasn't in the coupler but still in the bearing and torqued the inner race of the bearing a little in the right direction and the drive shaft slid right in bumping up against the bell housing with ease. With alignment issues I wonder if we worry whether the engine is in the right position before we check to make sure whether we have exhausted all possibilities of the gimbal bearings position. If one or the other is in the wrong position the drive shaft won't line up right?

 

[peteua636]

Re: is this an alignment problem?

I am guessing this is so. What I found is that by doing it the "clymer" way and trying to count threads is rather difficult. I re-checked mine and found that the left motor mount was not equal to the right using and I.D. caliper. Now having the height the same on both side the pulsing vibration is gone. AMAZING!! it was off by almost 1/4". Glad I kept on trying to smooth it out!!<br /><br />Thanks for everyones help!!

 

[Fishermark]

Re: is this an alignment problem?

My Mercruiser installation manual suggests "setting" the gimbal bearing after inserting the alignment tool by hitting the end of the alignment tool sideways in 90 degree increments. In other words hitting the end of the tool upwards, then downwards, then left, then right. This insures the gimbal bearing isn't out of place. Is this what you mean you you say you "torqued" the inner race?

 

[itstim]

Re: is this an alignment problem?

I think what happened in my case was when I put the drive shaft in after alignment the 1st time that I may have bumped the inner race so that it alone was not aligned anymore. When I "torqed" (slighty moved) the inner race in the right direction the drive shaft slid right in...and I mean right in, bumped up mated surfaces.