Mercruiser 140 engine/gimble alignment questions

[Wakesilver]

Hello,
I am finishing up replacing the engine coupler on an early 70's vintage Mercruiser. I did the motor mounts and coupler as people here suggested, as well as made an alignment bar per the sketch from Don S.

I have taken the front mount up and down to the point where the bar will not go in, and I think I am back about in the middle. The bar slides in easily up until the last inch or so, then will slide in with a slight amount of pressure, like pushing on it with two fingers. More grease seems to be on the bottom than on the top

Is this normal? Or should the bar it slide all the way in and out easily with the same grease marks on all sides? I have heard that sometime the couplers are not totally true, which means it will never get any better unless it is swapped out. I heard of people whacking on the bar too to recenter the rubber in the hub but that seems a little risky.

Thanks!

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

I don't know who told you to hit it with a hammer but next time they do, hit them with the hammer instead.

LOL

As far as turning the motor 180 goes, pull the plugs and spin the balancer in front?

 

[cr2k]

Re: Mercruiser 140 engine/gimble alignment questions

It is absolutely important that you get the spring/spacer/washer pack on the rear mounts in the exact order. Otherwise you will never get the engine aligned.

If this is not your problem then it sounds like you need to come down a little with the front of the motor. This will slightly raise the back angle.

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

It is absolutely important that you get the spring/spacer/washer pack on the rear mounts in the exact order. Otherwise you will never get the engine aligned.

If this is not your problem then it sounds like you need to come down a little with the front of the motor. This will slightly raise the back angle.

This make sense, thanks.

I used the newer style OEM mounts, taller than old with serrations, which have instructions say not to use the old spring washers. But they also ship with two small washers "just in case"

I have been doing all of the adjusting work in the front.

So if the back end is off (from the new mounts) the front adjustment will never totally "fix" anything since the parrallel relationship between gimble and rear of motor would be gone.

Maybe it is time to put those washers in and see if there is a change.

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

I tried the washers, and the bar locked up immediately.So I pulled them out and am back on the front.

The front mount adjusting mechanism is quite ingenious. I think that before I was forgetting to hold the threaded rod still while I adjusted the upper nut to lower the motor mount.

It seems to be getting better, thre grease pattern is not so much on the bottom and more on the sides and top. Would theory state that a perfect grease mark would be one where there is grease everywhere on the bar in a striped pattern with none of it scraped clean?

Thanks!

 

[cr2k]

Re: Mercruiser 140 engine/gimble alignment questions

Yes that is the pattern you would strive for. As long as you are very close and the drive does not give you any problem going in you should be very close.

Don't forget to use spline grease or similar sticky ptfe grease that will stay.

We had a guy do his own coupler and disregarded the washer stack on the back. When he came in to the shop he finally told us he really had to force the drive on. His new $400 coupler lasted 1/2 way across the lake.

We sold him a used one and gave him an illustration of how the stack goes and he has not been back.

I have used tape to hold the nuts under the mounts with success.
And rubber bands to hold the stack on the bolt inserted thru the top.

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

Thanks, CR2K. I have some Valvoline Cerulean, lithium complex w/ additives. I was told not to use the "brand name" spline grease as it dries out quicker. I hope it plays nice with the other three kinds I see in there.

I have not had to use tape for the nuts, plenty of room to get at them as my boat's jump seats and engine cowl have been replaced with a big box that covers everything in back and comes completely out of the boat.

I hope to play a little more "motor mount limbo" and get it all put together this weekend.

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

I bottomed out the front mount with "dubious" board from previous owner under mount. I switched to a 1/4" thinner board and now I have room for adjustment. I was able to measure from the alternator shaft to the floor of the boat to keep my ballpark distance, and to find out the upper and lower limits where the shaft no longer slides in. Now I need to make the final adjustments.

 

[Wakesilver]

Re: Mercruiser 140 engine/gimble alignment questions

It's all back together, all that is left is hooking up the battery. Thanks for the help!