I spoke to Paul Dennis today re purchase of one of his customized tides marine shaft seals for my F30.
While we were talking I mentioned my motor mounts were at least 25 years old and may be the originals from 36 years ago. He thought I was way overdue for mount replacement. I am at about 2500 hours.
So I am buying a set of mounts from him to go along with the seal.
The question is, is a motor mount replacement and engine alignment doable as a dyi project? Has anyone done it themselves? I have watched videos of mount replacement and subsequent alignment. It looks tedious but not technically complex. I am confident I can lift the engine slightly to take the weight off the mounts and I am comfortable with removal of old mounts and install of new. It is the alignment that scares me a bit.
I would appreciate anyone’s thoughts.
WRT the seal, I’ll have to haul the boat for that job but it also looks doable DIY.
I had removed the Yanmar 3GM on my Freedom 33, to renovate it.
So I had to realign the engine once it was back on board.
I used a thickness gauge shim. To be inserted at the level of the coupling
I tried to do my best.
When I first started the engine, it vibrated quite normally.
Hi Mike,
I did the exact same job you are doing now on my F28, including getting the Tides Marine shaft seal from Paul Dennis and replacing the motor mounts at Paul’s suggestion. I had a nightmare of a job freeing the coupling from the end of the shaft so that I could remove it. I ended up building a mini “gantry” out of scrap lumber so that I could lift the engine up a few inches using some 1/4" threaded rods and to get a gear puller on the end of the coupling, which finally freed it so I could pull the shaft out. My boat had the original Syntron non-lubricated seal so the propeller shaft was toast and needed to be replaced as well. I also built up the outside of the shaft log with a few additional layers of fiberglass cloth and epoxy so the new seal fit over it snugly.
After all that, swapping in new motor mounts and aligning them was the easy part. It was my first try at doing the alignment and although I get the theory of measuring the runout with feeler gauges, I found it difficult to achieve that level of precision in practice. Nevertheless I did the best I could and it ran fine when I was done. There are two things working in your favor. First, the Yanmar mounts even when new are pretty flexible compared to other brands, so they are a little more forgiving if the alignment isn’t perfect. Secondly, if worse comes to worse and you have to adjust the alignment again, it’s no harder to do with the boat in the water so you don’t need to have her hauled again.
Best of luck, the Tides seal has worked great for me.
The project is diy doable but will take some time and effort. I took it on because boat was taking on water over memorial day weekend so getting a mechanic was not possible. Looking back I think I would have had a mechanic do it.
Do not be surprised if scope expands beyond shaft seal: mounts, shaft, flange and cutless. It turns into the typical might as well replace while I am here syndrome.
A few thoughts come to mind should you opt for DIY. Forgive the bits of rambling.
Had to trim the tides seal to fit in small space between the shaft log and the flange.
Spraying penetration oil on shaft flange and mount nuts was helpful if they are very rusty.
Getting flange off the shaft can be a challenge. Used a socket in between the two flanges and compressed with the nuts and bolts. The shaft must have no scoring where the new tides seal will sit or it will leak and you will have to re-do the job.This usually is why a new shaft is put in. A paid mechanic would probably just cut the shaft and replace it to save time. In any event this part is the biggest headache.
If the shaft is out and being replaced the cutless bearing can be cut out with a sawzall. It will have a few allen socket set screws on the strut. Have to sand bottom paint off strut to expose.
There is a tool that can force the cutless out with shaft in place.
Successfully aligning an engine with old rusty mounts is not likely to be possible. So it is on to mount project. Taking some baseline measurements for the mount height and line up is helpful for the new mounts.
The nuts on the studs were 24 MM. Two wrenches, a deep socket and a set of ratchet extensions will be helpful. The extensions come in handy for the nuts on the mount feet. Really helped get access. Replacing one mount at a time seemed safest.
Jacked and blocked front of engine with 3-4 inches to clear and replaced both front mounts. This sounds weird but inflating a basketball under the rear up the engine worked great. In some cases it is easier to remove the mount and bracket as a unit.
Feel free to reach out with questions and good luck
Thank you guys for responding. Sounds like I can get the job done myself.
The reason this is important for me is that I had a huge hassle dealing with a seal change two years ago. I am using a lasdrop. I installed the lasdrop successfully in 2018 and it performed very well for about four years. It began leaking eventually (as expected) and I planned to replace during a bottom job haul out. Holy cow, this seemingly simple bob turn into long running mess. I had the boat in the yard for almost six months, much of which was “nothing happening” time. Turns out I had leakage from the strut attachment bolts in addition to the seal, the heads of strut bolts were hidden under the diesel tank. It’s a long and painful story. Wound up having to replace the shaft which caused removal of rudder which caused issues with steering cable tightness which caused autopilot hunting … Good God!!
Anyway, Now I am back to seal leakage, fairly severe leakage at that. I do notice a slight kink in the flex tubing connecting the seal housing to the fiberglass stern tube. I am thinking it is possible the engine alignment is off or has been impacted by these very old mounts. The result is a misaligned shaft transiting the shaft seal leading to leakage.
So the first step of my plan is to replace the mounts and realign as a Hail Mary solution to the leakage issue. Either way, the mounts need to be replaced. I figure if I do it myself I save some dollars and, If no joy on seal leakage, then step two will be a haul out to replace the seal with the Tides Marine, reconfirm alignment, get the bottom done and pull the mast for an overdue masthead refurb. Last time I had it out was 8 years ago.
Pearce, man you have that right regarding project growth. It is growing as I write. And it grew like bamboo when I last had the boat in the yard. I swear, I was almost ready to buy another boat!
I do have a newer shaft and with the lasdrop lip seal I think I may have dodged the shaft scoring issue…hope springs eternal.
Thanks for the tips, excellent. The basketball idea is really helpful.
You mention you had to trim the Tides seal. Was this a modified seal you purchased from Warren River or directly from Tides Marine. I think Warren River modifies them for our tight space…maybe not enough??
With regard to the shaft flange. That was replaced two years ago along with the shaft. I had a big hassle separating the two before the replacement but I am hoping their relative “newness” will make this process slightly less painful.
And, finally, the cutlass bearing. Good point, might as well replace that too. I think last time I did it was about 10 years ago. Probably should have done it at shaft change but that whole mess was so overwhelming I just wanted my boat back together and to get out of that boat yard asap.
Since you have already done work recently it should all come apart fairly easy. Maybe you could separate the shaft and flange and install the new seal and then tighten it up.
I knew the Tides Seal would need some trimming when I ordered it. Paul was very helpful and gave great advice. It just depends on the space you have. Might fit without cutting.
Measured the seal up and marked it so two clamps would still fit on both sides and it the whole seal would clear. Then a put short pvc pipe inside the seal with a hose clamp over it at the mark. Use the clamp as a guide to get a clean cut with a sharp razor knife. Repeat for the other side. Go slow, measure twice and it should be fine. It cut fairly easy.
Pearce, one basic question. We have the coupling over the shaft and a coupling attached to the transmission. These are bolted together for standard ops.
When one separates the flanges does the shaft extend into the flange attached to the engine or is it stand alone within the aft flange with torque transmitted via the attachment bolts?
I should know this because I had the flange off two years ago but I can’t remember exactly how it was set up in this regard.
OK. Thanks a lot. This will make it viable for me to remove the bolts and nudge the shaft back a small bit without having to remove the flanges at all. I have 1/4 to 1/2 inch to work with before the shaft flange comes up against the seal housing screw heads. I assume that ring on shaft flange face which mates to trans. flange is not very deep?
All I plan to do at this point is replace the motor mounts. So, in theory, remove the flange to flange bolts and nudge the shaft back just a bit so there is a small gap between flange faces. Then use a feeler gauge and, no doubt, half a day fussing around with motor mount bolts to get alignment sorted, then reattach shaft and all good…correct?
I am skipping the part about unloading the weight on the mounts in order to extract old and install new. It is understood I will need to carefully measure the height of original motor mount bolts to get close to correct heights pending fine tuning at the coupling faces.
I also realize seal housing replacement will be a job that must be done out of the water. I wanted to try mount replace and alignment to see if that may help with seal leakage.
Sounds like a plan. Since the mounts need to be replaced anyway it is worth getting it done. Checking the alignment cannot hurt. Might check it before starting the mounts replacement to see if it is off.
Seems unlikely that this would help with shaft seal leaking. But for the future seal I have heard real bad alignment can cause premature shaft seal wear.
Must be nice not to be out of the water for 6-7 months. Was 8 degrees this morning in MA.
Yea, not having to go into winter layup is a good thing, but there is something to be said about having to come out every year so one can accomplish various out of water jobs on a routine basis. It is very easy for us year round in the water types to kick the can down the road as far as possible due to hassle factor and cost associated with hauling the boat.
I agree on the mounts - unlikely to help with leakage but given they should be replaced regardless I figure it is worth a shot.
And, yes, I intend to check alignment at disconnect and see how it looks before I touch the mounts. Perhaps that may reveal some misalignment which may have lead to excessive seal wear,
The other item of interest is the fact my current lasdrop is connected to the stern tube by a very short and very rigid piece of wired tubing. Paul Dennis tells me the Tides Marine seal comes with a special stern tube connector made from a durable but more flexible material which helps with self alignment if I DO have some residual misalignment after I a complete the mount replacement. I want to do some sailing so probably have to wait until March for the haul out and seal replacement.
One question I had asked I was still hoping for an answer to: You mentioned the shaft flange has a circular lip which fits into the engine side coupling. How far does that lip stand from the shaft flange face?
