Mercruiser alignment issues

[tigger3650]

Problem started awhile back when I had a newer 3.0 installed. After it was installed I would get a rattle from the stern when stressing the u-joints (drive full left/right/up/down). Mechanic said it wasn't bad and the metal hull just amplified it. Unfortunately I was out of town and didn't have time to get him to fix it. Getting the boat ready for a trip to the Keys in 2 weeks and needed to replace the shift cable. Since I had the drive off, and knowing the rattle issue, I replaced the Gimbal bearing, 1 u-joint, and the bellows. I only replaced 1 joint because 1) I couldn't get the one closest to the drive out. Everything I tried kept catching on the drive housing and 2) While installing the other one, one of the needles moved and I ruined the joint. Good news is, the one I was able to replace was stiff, but now both move freely. There is the long/brief history. Now to the issue at hand:

Obviously (I think) the motor was out of alignment to begin with. Once the new bearing was in I aligned the motor. Bar sliding with just 2 finger and would spin easily. I go to put the drive on and fight for three hours trying to get it to seat all the way in, rechecking the alignment multiple times. It would slide in to where the threads would be flush with the mounting surface of the drive and not move any further. A couple of times I got about 1/4in of threads to show but that was it. Finally I gave it a solid whack with a chunk of wood and it went right into place. Fired it up on the muffs, shift cables all adjusted everything looks/sounds good (except the exhaust bellows came off the outdrive side). I put the bellows back on and headed to the ramp the next day. Put the boat in the water, pull away from the dock and as I turn the rattle is worse than it ever was. I don't have to turn the wheel far at all and it starts rattling.

I pulled the drive off and the alignment bar won't even go passed the coupler and touch the splines. I move the front mount from full up to full down in 1/2 turn increments and it never would slide past the coupler. I even tried lifting up on the front of the motor several time while someone applied pressure to the bar. No joy.

I then tried pulling the bearing back out to re set it. After several attempts at what seemed like no movement, I gave up on the route and tried to slide the bar back in. I gave it a few whacks in multiple directions like the book directs and the bar will now go in with quite a bit of force. I am still unable to align it back to where it slides in and out easily. It was getting late so we threw the drive back on and this time while it was on the muffs I moved the drive side to side. Rattle is still there.

What can I try next?!?!?

Should I try adjusting the mount a few turns with the motor running and see if the rattle changes?

 

[alldodge]

Try rotating the motor 90 degrees or so, and see if it gets worst or better. If rotating changes things then the coupler is warped.

Also check the dimensions of your alignment bar to ensure it was made correctly. The dimensions are in the sticky's

I couldn't get the one closest to the drive out. Everything I tried kept catching on the drive housing

This statement gives me concern, because you should be able to get to the rear U joint. Has the drive been taken apart and some time

 

[tigger3650]

The drive was "rebuilt" before I purchased the boat. Other than the water pump being replaced, no It has not been apart recently.

I have rotated the motor several time and did not notice much change.

I'm thinking of pull the new bearing and reinstalling it. What are the chances of damaging the bearing by doing this?

What is the level of "tech" in pulling the top off the drive and possibly pulling that shaft. It resembles a differential on an axel and I'm not overly comfortable when I'd comes to shims and lash adjustments?

 

[alldodge]

Do see removing the gimbal bearing without damage, even if only slightly. If it is seated and is smooth to the feel you should be good.

Your going to need some tools to remove/reinstall the drive shaft. The pic is a Bravo and you can see there is plenty of room to get at the rear U joint. If your is different post a pic

Also with drive off, can you move the drive shaft yoke in and out?

 

[tigger3650]

My shaft sits further back in the housing. I will double check the sliding movement but I don't recall any movement of the yoke.

As far as tools, I have a pretty good collection of them. What specifically / special tools may be needed? I could look it up but I am at work and don't have access to my manuals handy.

 

[alldodge]

Having an older drive you may be ok wit no room for U joint, would need someone more familiar with them to advise on U joint.

Bearing Retainer Wrench 91-17256
Torque wrench ft lb ( depends on length 15 inch = 111, and 36 = 91)
Rolling torque wrench 6-10 in lb (if you find play and just to insure its correct)
To check gear spacing need shim tool 91-60526 (if needed)

Measure the length of the drive shaft and see if its 9 9/16 inch long. If its 8 1/8 long, then someone used the older drive shaft

 

[tigger3650]

Thanks, I will check it this evening when I pull the drive again.

Any comments on trying to adjust the mount while idling to see if the rattle changes?

I also reached in and felt the bellows to see if I felt the shift hitting there, and it isn't. I pushed the drive over and held it hard for a few seconds in each direction. I plan on taking a closer look to see if anything is making contact.

 

[alldodge]

Any comments on trying to adjust the mount while idling to see if the rattle changes?

IMO, while this may reduce the noise, it would only be giving a false sense of getting better if it did. If alignment and all things are correct then there should be no issues/sounds

 

[tigger3650]

Another quick question, can I pull the cover off the top of the drive without draining it or having to take anything apart? Just want to see if there is anything obvious.

 

[alldodge]

Yes

 

[tigger3650]

OK, so I pulled the drive again and found nothing obvious. I looked for any signs of contact being made both on the shaft/yokes or inside the transom assembly. Nothing. The drive did come off very easily Normally I have to gorilla handle it to get it out. I know the alignment was not good when we put it back together last night, but didn't want anything getting into it.

Here is the puzzling part. I slid the alignment tool in and it went all the way into the splines. Something we fought with the night before. I tweaked the motor mount a bit and it slides all the way in super smooth. We rotated the motor and checked the alignment multiple times, a few tweaks (less than 1/4 turn) here and there. Tightened everything down and checked the alignment again, turning the motor all around and it is perfect. Slides in and out with 2 fingers and I can't tell a difference in the spline marks on the grease.

Put the outdrive back on with fingers crossed. It slid in really smoothly. Has never gone on that easily either. Started it up and still have the rattle in tight turns. It's not coming from the drive itself. Not coming from the bell housing. Laid a pry bar on the shaft of the coupler and it didn't even vibrate much less bounce.

Pulled the drive again and rechecked the alignment, it was still perfect.

I'm thinking of ordering 2 more ujoints and replacing both(somehow ) to see if it cures it.

Any other ideas?

 

[tigger3650]

Forgot to mention the drive shaft does not slide in or out at all.

 

[alldodge]

Have you done this yet?

Measure the length of the drive shaft and see if its 9 9/16 inch long. If its 8 1/8 long, then someone used the older drive shaft

 

[tigger3650]

I forgot to ask, which portion of the shaft? Overall length from the housing to the end of the splines? Splines to yoke? Yoke to inside the housing?

I did measure one part and it was 15" and I remember earlier in the thread that was mentioned concerning torque values.

 

[alldodge]

This

 

[tigger3650]

This brings up another thought. The boat is an '85, the motor came out of a' 90'sish Bayliner. They left my outdrive and transom assembly and said they couldn't put the newer one in because the cutout in my transom was bigger than the one required for the newer one. I was not about to replace the transom, again. I was wondering if there is a difference here?

 

[tigger3650]

Is that the splines end or the end that goes into the drive case

 

[alldodge]

That is the spline end, the one that goes into the coupler

 

[tigger3650]

Ok, I will measure that this afternoon/ evening when I get back to the boat.

Just out of curiosity, where are you going with this?

Let's say it is one or the other, what next?

One of the thoughts we had was if the shaft was too long/short what would it cause?

I can see being too long, it would "kink" it at the u-joints, but wouldn't it do this all the time, not just when articulated?

Too short, I would think it would pull from the splines?

Another note, the reseal kit came with 3 O-rings for the shaft. My shaft only has 2. This may/not help with identifying the shaft length.

 

[Maclin]

If one of those 3 is larger than the others then that one is probably the water passage Oring.