Engine Alignment help please!
 

Hi There

i am trying to align my 2006 bravo one/350 mag mpi. I stripped an aluminum coupler in the first 150 hours of the boat. I bought it used with only 20 hours on it. So i bought an actual merc alignment bar and the 91-863372 adapter i believe that fits in the bellhousing. I have moved my engine fully up/down and the gap on the top of the tool doesnt change! And to make things worse im having no luck reading the grease marks. Seems no matter where i move it the grease marks are heavy on top and port side. I tried moving the engine side to side a tiny with a porta power and still no change. I also have a digital protractor and the transom angle is 14 degrees. I read on here that merc uses a 13 degree offset so i tried to set the height all around 13.5-12.5 and the bar would barely go in after trying to center gimbal bearing. The bar goes in fairly good around 14.2-13.9 degree angle. I just cant get it to a 2 finger pull. And its not the bar, it goes in nice to my spare couplers and gimbal bearings! Its driving me nuts why does the adapter tool in the bellhousing not working? Am i doing something wrong? The bellhousing hinge pins are tight and so is the top and lower gimbal ring pins. Anyone have any advice? I prob have 40 hrs into trying to get this alignment perfect. And jumping in/out of the boatba million times is getting old. I attached a pic of the adapter at a point of when the bar was a 2 finger pull and i shouldnt have moved it but i was trusting the tool.... i kept track of how many turns i moved it and put it back but no luck. Im close but want perfect!https://cimg4.ibsrv.net/gimg/www.off...5576c8098f.jpg
https://cimg5.ibsrv.net/gimg/www.off...b378ab2689.jpg
https://cimg6.ibsrv.net/gimg/www.off...a014c88938.jpg

I just use a bar on my 350/alphas..not familiar with adapter..but the new couplers were hard for me to align as well.

Did you use the new rear motor mounts with no spring washers (or alternate one flat washer) at rear of motor? I replaced mounts and engine a bit low in rear for alignment (my experience) Merc provided a flat washer which I did not use...next engine I probably will.

Maybe that is your issue...changes at front are hard to read as rear is too low (thus the heavy reads on top). Maybe check engine for level as a place to get grounded...I feel your pain..in & out of the boat ...:(

Lane

The oem 2006 chaparral setup didnt use the washers. For the heck of it i replaced the rear mounts and made sure they were the same depth as orig by using a starrett depth mic. The coupler wore in 100 hrs so obviously something was not correct out of the dactory. I had it good at one point so i know its possible. Just having trouble reading where to move it. Thats why i bought the plate adapter for the bar. But i can move the engine mounts 13 turns and the gap on top doesnt change.

The bearing itself pivots. If you stick the bar into just the bearing, not all the way into the coupler, you can move the bearing around with the alignment bar. You could also try turning the motor over 180 for chits and see what happens, but that’s usually only a issue on a old coupler. You should have either the fiber washers or the double wound lock washers between the inner transom assembly and the engine bellhousing.

I always smack the tool side to side and up and down with a rubber mallet til its aligned

There is a procedure for putting the coupler on, found that out when i did mine i had to use bolts with tapered heads I think they are called flat head.

Next is the bearing, i didnt trust mercury and used the adapter to verify the bearing was aligned on a new transom assembly ( smack it with a hammer like f2 said above) From that point i started alignment,

i kept getting top tight as well, but but it to me it was the gimbal housing, a liitle pressure on the bottom pulling it out To counteract the bellows yanking it down and it went away.

I started a thread. coupler runout ?? Here on offshore, it has some pics of what had to be done but i cant figre out how to attach it to this thread, cant copy paste drag drop on a tablet Or at least i cant

i have the fiber washers. Yes i smack the bar up/down/left/right after every single movement of the engine mounts to align the gimbal bearing. I think i've done this process 200 times or more! Then insert the bar many times before judging if i have to move it again. The new coupler is not out of round. When i had the engine out and after i centered the coupler using tapered bolts i used a dial indicator to check the flywheel runout and the total runout at the end of the splines. There is .005 total runout at the coupler. Has anyone used this adapter plate before?

The plate is used to determine which way to adjust the mounts. It is held firmly against the bell housing with the alignment bar full seated. Alignment is check by sliding the plate back away from the bell housing or removing it from the bar.

Are you pushing and holding the plate against the bell housing, with the alignment bar fully seated?
From the pics it looks like there is a gap all around, is this correct?

There is a gap on the top and touching at the bottom. That particular picture is at a point where the bar slid in nice and easy. Bar fully seated and adapter pushed against bellhousing. It stays that same gap no matter where i move front mounts. Ive gone fully up and down. Should i try the stainless washers? Would lifting the rear close the gap. Ill use a depth mic to see how big the gap is but its probably close to the .100 shims i have.

thank you everyone for taking the time to respond!

Brian

https://cimg7.ibsrv.net/gimg/www.off...c4ae46d67b.jpg
gap at the top and touching at the bottom to me means the engine is nose down, lifting the rear would exaggerate that, what kind of front mounts do you have ? something like this

If pushing it in, and it touches on the bottom but not the top, and the gap on top is evenly tapered from top to bottom, the motor mounts need to go down evenly. Note if the motor is dropped down and not evenly, the twist will make it feel tighter.

Also good to pull the pin out of the steering arm, so you don't have to make sure the wheel is dead center.
Push in on the plate and use feeler gauges to measure the sides to determine a twist exist.

F2, yes very similar. Alldodge, its an even taper from the gap on top to slowly touching at bottom. After i get this cone clutch in im going to the shop wheee the boat is. Ill suspend the engine from the crane on my service truck and try to even out the weight on each mount to "reset"! So throw rear mount washer idea out? Do any of you ever use a protractor when aligning?

thanks again everyone!

I've never used a protractor. IMO the angle of the transom is irrelevant, the transom plate and front mounts are all that matter.

Would not do washers, installing washers would keep the bar from going in the coupler

Have you rotated the motor 90 degrees to see if the alignment changes

yes i have rotated it. Because i upgraded to a steel coupler last year and went through two new bad ones before going back to an aluminum! I verified this one was had only .005 runout installed. As far as angle i was just referencing some old posts that stated that all merc transom plates are designed for a 13 degree difference between the plate and engine. So i have just been checking it and keeping note. So if i put the engine all the way down on the mounts and the gap still doesn't change, then what? I'm puzzled of why there was the gap on the plate in the pictures and i could pull the alignment bar out with two fingers? I don't know the pitch of the mount stud but to close that 1/8" gap how many turns would you estimate?

If you can put the mounts all the way down and still get the alignment bar in, I think you have something else going on. Maybe the bar is not going into the coupler or something else

If you can put the bar full in, and can remove with 2 fingers, I think your good

As for my 90 degree comment, I wondered if the alignment bar resistance changes if the motor is rotated

Get a dowel rod, stiff piece of wire or other which is long enough to go to the rear of the coupler. Mark the rod at the face of the bell housing, now stick the alignment bar and mark it. Compare the two and the rod should be a bit deeper but not that much

Ok i have my porta power under crank pulley. Lower mount nuts fully lowered. Engine all the way down and align bar pulls out with 2 fingers and same gap on top with plate. I can move the engine up probably an inch and bar still pulls out with 2 fingers. Gap on plate never changes. Whats up with that?

Wrong size coupler, or alignment bar is not going in the coupler

x2 Words right out of my mouth.

The bars are the same size.
Try raising the rear mount with washers until the plate is centered and flush with the bellhousing. I have that same setup.
As you raise the rear of the motor you will have to raise the front mounts also to get the alignment tool to line up.
Years ago I was blowing a coupling at will every weekend. My tool went in and out like nothing. I even took it to a so called MERC. expert. charged me $100 and I blew the coupling that weekend.
I finally took everything apart and took a lot of time looking at everything. I finally figured out that my rear mounts had sagged and because the gimbal bearing pivots I would lower the front mounts and the tool would line up. BUT what was happening was the input shaft was at an angle to the input yoke on the drive. This meant that the two shafts at each end of the U joint were not on the same plane. ( I am not talking angle but plane) If they are not on the same plane this binds the U joint and causes side loading of the U joint and that side load gets transferred to the coupler. I had the plate made at a local machine shop and I use it every time. I was at 500+ HP before when I was blowing them. I am now at 800+ HP without any problems.

After I had the problem with the rear mount I started shimming my rear mounts so they can't ever move. I install washers and shims to set the height and then use a shorter bolt with very large washers on top to stop any up and down motion. The Daytona also has solid front mounts.

Tinkerer i will try the washers. It sounds u ran into the exact problem. The gimbal bearing pivots to keep aligning as i drop it on the front. It must have been tight because it was not even from side to side. Im sure thats why with the porta power on the crank it goes in/out with 2 fingers. This is not a performance boat by any means but i blew the orig coupler in 150 hours. I bought the boat used with only 20 hrs on it. The tool is definetely fully going into the coupler and is the correct diameter. I have a merc brand tool and aftermarket. The merc tool is .003 larger than the aftermarket tool in the gimbal bearing area and fits nice. I have a spare coupler i keep on the shelf and it slides in there perfectly as it should.

Ok .100 washers are in. The plate was over 1/8 out and now its only .065. I didnt measure the od of the washer. Does anyone know the size? Should i add or make a single .165 shim? Tinkerer how far out was ur plate that caused you to eat couplers? I was cheating by lifting each side with a porta power. Not sure i have vertical clearance to add much more. Really dont want to pull engine cover off...lol.

thanks for the help!

OD of mine is .872..assume .875 nominal. .104 thick (saved them for another day)...looks like you are making progress!

After installing the .100 washers i was able to close the gap by raising the front. Shes nice and flush and bar slides out with 2 fingers! I wonder what the deal was from the factory? Because i even replaced the rear mounts about a month ago so they were not sagging. Transom has no signs of rot and it stripped the first coupler at 4 years old. Was the inner transom plate just installed wrong? Gotta throw the drive on in the morning and go for a test run!

Everyone who helped me, thank you very much!

Sorry I don't remember how much it was off. It was about 30 years ago.
Years ago I had an on line fight over this same subject with the then MERC. guru on this site. He told me I didn't know what I was talking about. And I told him that about this subject I guess I knew more than him. To say that I got flamed was an understatement.
I found that with most boats IF the alignment tool is parallel with the running surface it works.
I spent a lot of hours figuring out what was wrong that was causing me to blow couplers.
I have NEVER blown one again.
I just know for a fact that if the rear mounts get out of place high or low you can raise or lower the front of the engine to get the alignment tool to say the engine is perfect but it isn't and the more HP you have the sooner the coupling will blow due to side loading.
The center line of the input shaft and the center line of the upper out drive shaft must be in the same plane. They can be angled because of trim or turning but this does not move the center line when the drive is at the neutral setting.
When they are not in the same plane the U joint is crabbed sideways ( up and down actually ) This puts a side load on the coupler that it is not supposed to see.
I literally could blow a coupler in less than 5 hours run time.
Sounds like you are getting it fixed.
I don't understand why the rear mounts have rubber inserts at all. I understand vibration issues but I have never felt any and I have been locking down my rear mounts for at least 30 years.

Well test drove it today. Small vibration from about 800-1200 rpm. Can feel it with my hand on top of windshield. I think i can do better as far as alignment. Getting it perfect with everything tightened up was just a pain in the ass. My merc bar i could just barely pull it out using my middle and pointer finger. So i think i can do better. Ill try again this week. What i found interesting is for the hell of it i checked the angle of the engine and its 13.0 degrees!https://cimg7.ibsrv.net/gimg/www.off...ee2686e3f9.jpg

best tool for any sterndrive alignment is the ITS alignment tool by far. It will tell you coming thru the gimbal bearing how far off your not centered,

The next thing you want to do is by hand at the crank turn the engine over every 90 degrees and keep checking the ITS tool in its position to make sure it never changes, It is best to have 2 people one eying up the rotation of the ITS alignment tool and the other hand rotating the engine every 90 degree turn stop at each 90 rotation. If that position changes at every 90 degrees of rotation or even at 180 of rotation then you have a warped coupler or bent flywheel or the coupler or the flywheel or both are NOT mounted perfectly flush.

Sorry I did get your PM but I am really busy and can not answer every single PM s . I try like hell to answer everyone but that does not pay my bills. Sorry about that one

This is a good tool to have but there is an issue with using it that will fool many for checking perfect alignment,

https://drive.google.com/file/d/0B4y...Z5a0Nhek0/view

The issue is the gimbal ring / bell housing will drop cause the the nut on top of the swivel shaft will loosen over time. This drops the bell housing down - with that said the tool / plate here in the pics is worthless unless you tighten / bring back the nut to spec clearance by tightening it. But that requires removal of the transom assembly to do so.

My buddy Mark and I just talked about this exactly. So Mark if you see this haha

Bup - no worries! I bought the tool listed in your second reply. I know exactly what you mean. My lower steering pin/bushing has a small amount of play and the bellhousing can move up/down a small amount. It definitely was able to get me close. And lead me to place the washers in the rear mounts so that's good. I will order the its tool tomorrow morning and give that a try. I replaced the coupler about a month ago and it had .005 total runout. After the first coupler failure i decided to put the stainless coupler with the snout and had two of them out of round like .030 with centering with tapered bolts per bulletin. Thats when i decided to go back to aluminum and get the alignment absolutely perfect. So how do i exactly use the its tool. I see a few pictures of it online. So place the bar in the coupler then slide the other part toward the gimbal bearing. And with a flashlight u can see which exact way the engine needs to move in order for the sliding piece to fit in the gimbal id?

thanks for the continued help!

Brian

I have a boat I just pulled the Bravo XR off. I will snap pics tomorrow of exactly what I am talking about and of course my not so great grammer when I do the write up. haha

If your gimble is is bouncing around , all the alignment efforts in the world won't do a thing and its only going to get worse untill you fix it,

So with the its bar fully in the coupler i can wiggle it around. There is a massive amount of slop. Ill try to post a link to a video.

https://youtu.be/gP0soIQK2L8

Your missing a sleeve that should slide over the shaft. My tool has one size that fits into the coupler and a slightly larger "step" that only goes into the gimbal bearing. It also has a stop that bottoms out at the bearing.
that is the wrong shaft for your boat or is is missing the sleeve.
Now we see the problem.
You must have the right tools for the job.

I have the stock MERC alignment tool. but then I installed an IMCO extension box. IMCO sells an extended tool. I couldn't wait so I made my own.

I have the sleeve that fits over the bar. I thought the idea of this tool is to put the bar in the coupler then you want it centered in the gimbal bearing. That way u can actually see which way the engine needs to move. Then slide the sleeve on and make sure it smoothly goes into the gimbal bearing. I have so much slop between the bar and coupler i cant do that...

Some videos of a few new in box steel spare couplers i have with the bar in them.