Transmission troubles

[Bepi]

Great photos...the tackle setup used on the motor is very cool.

 

[gabosifat]

Was happy to see that the red dipstick handle wasn’t impeded by the heat exchanger- the bell housing on the M35 has a rounded indentation on the top which allows the HE to move further forward than in your case Bolo.
Anyway, gear is in, bell housing back on, and just reattaching HE and plumbing before swinging engine back on to the mounts. Didn’t change the mounts as they seemed ok. Onwards tomorrow and hope to work on the alignment.
Thanks again to all those helpful suggestions.
cheers,
Steve

 

[Loren Beach]

Didn’t change the mounts as they seemed ok. Onwards tomorrow and hope to work on the alignment.

If those are old mounts, like over 20 years, please do replace them. This is a great opportunity to do that chore.

 

[gabosifat]

I’d like to replace the mounts, but I’m way up in the middle of nowhere.
Does anyone know the number system for flexible mounts and when certain numbers are used compared to others???

 

[gabosifat]

Yet another complication! The new transmission is about 3/4” shorter than the old one, and doesn’t allow me to mate the coupling without water gushing in through the PSS shaft seal. Now it’s either a flexible shaft coupling in between, or what I’m just going to do now, which is dive to see if I can remove a shaft zinc to make it possible to possible to slide the prop shaft forward. Never seems to end…
Cheers,
Steve

 

[Frank Langer]

Yet another complication! The new transmission is about 3/4” shorter than the old one, and doesn’t allow me to mate the coupling without water gushing in through the PSS shaft seal. Now it’s either a flexible shaft coupling in between, or what I’m just going to do now, which is dive to see if I can remove a shaft zinc to make it possible to possible to slide the prop shaft forward. Never seems to end…
Cheers,
Steve

These jobs are always challenging and require lots of problem solving, but it sounds like you're doing a great job at it! Take it one step at a time, and before you know it, you'll be done and underway again. Good luck!
Frank

 

[Alan Gomes]

Yet another complication! The new transmission is about 3/4” shorter than the old one, and doesn’t allow me to mate the coupling without water gushing in through the PSS shaft seal. Now it’s either a flexible shaft coupling in between, or what I’m just going to do now, which is dive to see if I can remove a shaft zinc to make it possible to possible to slide the prop shaft forward. Never seems to end…
Cheers,
Steve

A flexible coupler would probably solve the problem easily.

As a rule of thumb, you would ideally want to see one shaft diameter's worth of overhang of the prop shaft past the strut. So, if you have a 1" diameter shaft you'd want to have an inch of shaft showing between the aft end of the strut and the front of your prop hub. However, you cannot always achieve this, depending on the geometry you are working with, including such things as the clearance between the tip of your blades and the bottom of your hull, and so forth.

I just mention this since you may be playing with the amount of overhang, FWIW.

 

[Dave G.]

The new transmission is about 3/4” shorter than the old one, and doesn’t allow me to mate the coupling without water gushing in through the PSS shaft seal.

If the coupling will mate you could loosen the SS collar on the shaft seal and slide it aft to the correct compression (3/4" I believe) providing the shaft will move forward enough of course. You are supposed to replace the set screws when loosened but you could do that when you get back to home port.

 

[gabosifat]

Thanks guys. Set screws out, but cannot get SS collar to rotate so I can slide it back on the shaft…

 

[Dave G.]

There are o-rings inside the collar. Try flushing with soapy water. Also there are 4 set screws, 2 sets of 2 stacked on one another.

 

[gabosifat]

Collar moved finally with soapy water soaking, and two pipe wrenches. Managed to pull shaft forward to mate with transmission coupling after diving to check prop and zinc clearances. No problem there. Have to leave the boat for a week or so now, then on to engine alignment, and reinstalling plumbing and cabling.
Has been an ordeal for sure!
Will post an update once I’m back up here and finishing off the job.
Cheers, and thanks to all!
Steve

 

[gabosifat]

Hi Everyone,
An addendum to our transmission troubles posting. We’re still up here in Bella Bella. The engine is about to come out for the 4th time. We got everything back in, spent a day and a half doing the alignment meticulously. New engine mounts. New gear and throttle cables. Started up, engine was very smooth in neutral, but in gear at low revs it shook the whole boat violently. Turns out two things appear to be happening. 1. The new (different brand) mounts appear to be too soft. 2. The new transmission meant the whole engine had to come up on the mount posts by about 7mm. This allows the 5/8” studs of the mounts to move much more, hence the vibration. So our plan now is to re-install the old mounts, but shim them up to keep the engine lower on the studs.
Fingers crossed…
Cheers,
Steve Gabbott
E35/3 Silent Dancer
Gabriola Islnd BC

 

[Frank Langer]

Hi Everyone,
An addendum to our transmission troubles posting. We’re still up here in Bella Bella. The engine is about to come out for the 4th time. We got everything back in, spent a day and a half doing the alignment meticulously. New engine mounts. New gear and throttle cables. Started up, engine was very smooth in neutral, but in gear at low revs it shook the whole boat violently. Turns out two things appear to be happening. 1. The new (different brand) mounts appear to be too soft. 2. The new transmission meant the whole engine had to come up on the mount posts by about 7mm. This allows the 5/8” studs of the mounts to move much more, hence the vibration. So our plan now is to re-install the old mounts, but shim them up to keep the engine lower on the studs.
Fingers crossed…
Cheers,
Steve Gabbott
E35/3 Silent Dancer
Gabriola Islnd BC

Hi Steve,
I'm sorry to hear about your continuing troubles. I can't imagine raising the engine four times! I think you get the award for perseverance!!
Could the vibration in gear be caused by an unbalanced propeller or worn cutless bearing? Is your alignment perfect, or at least within .002 specs?
Good luck in getting it solved!
Frank

 

[gabosifat]

Thanks for your response Frank. Don’t think anything has changed re prop (maxprop) or the cutlass bearing (things were dead smooth before. Shaft spins very freely either uncoupled to engine or bolted up to the coupling. Engine very smooth at idle (unless revs very low), and dead smooth right up to full throttle in neutral. However as soon as in gear, the vibration is pretty extreme at lower rpm’s. As you throttle up in fwd gear, it gets a bit smoother , but you can actually see the engine hobbyhorsing for and aft on the mounts. So to me, either the new mounts are too soft, or the raising the engine higher for the replacement transmission has pushed the mounts to their height limits. We spent a long time on the alignment (a day and a half) which was difficult because of the pss shaft seal. The only way to do that is to centre the shaft in the log, make sure it spins smoothly, and fix it in place, then align the engine to that. Engine disconnected and ready to pull again tomorrow. Will re-install the original mounts shimmed up so the engine sits lower on the mount posts. Hopefully our theory is correct. Bella Bella is a nice place, but it’s high time to move on!
Cheers,
Steve

 

[Frank Langer]

Thanks for your response Frank. Don’t think anything has changed re prop (maxprop) or the cutlass bearing (things were dead smooth before. Shaft spins very freely either uncoupled to engine or bolted up to the coupling. Engine very smooth at idle (unless revs very low), and dead smooth right up to full throttle in neutral. However as soon as in gear, the vibration is pretty extreme at lower rpm’s. As you throttle up in fwd gear, it gets a bit smoother , but you can actually see the engine hobbyhorsing for and aft on the mounts. So to me, either the new mounts are too soft, or the raising the engine higher for the replacement transmission has pushed the mounts to their height limits. We spent a long time on the alignment (a day and a half) which was difficult because of the pss shaft seal. The only way to do that is to centre the shaft in the log, make sure it spins smoothly, and fix it in place, then align the engine to that. Engine disconnected and ready to pull again tomorrow. Will re-install the original mounts shimmed up so the engine sits lower on the mount posts. Hopefully our theory is correct. Bella Bella is a nice place, but it’s high time to move on!
Cheers,
Steve

Steve,
I'm no expert, but I'm puzzled that the engine runs smoothly even at high rpms when in neutral, but hobby horses when in gear. If the problem is the motor mounts, wouldn't the engine vibrate consistently at high rpms, both in neutral and in gear?
I'm still wondering if something is amiss in the drive train to cause the engine to hobby horse in gear.
Keep us posted, and good luck!
Frank

 

[Dave G.]

However as soon as in gear, the vibration is pretty extreme at lower rpm’s.

It sounds like your shaft alignment is way off. 7mm is a big difference when trying to align the shaft with the engine, shaft log, and strut/bearing.

 

[Kenneth K]

Did you check with the engine mount mg to see if a stiffer absorption material is available for those engine mounts?

 

[gabosifat]

Hi everyone,
Update. I talked to a very reputable marine mechanic, and he’s pretty sure our problem is the new R&D mounts are far too soft for this engine. So, we’ve reinstalled the old mounts (and shimmed them up to lower the engine on the studs) (new transmission required engine to come up 5mm). Just in the process of aligning the motor to the shaft. I’ve included two photos. The first shows how we fixed the shaft in the middle of the shaft log (PSs shaft seal lets it flop all over the place). Second photo is an attempt to ensure that all four engine mounts are in the same plane - eyeballing a string across the back two mounts vs a string across the front two. Getting close on the alignment, will fine tune tomorrow, then hook up everything, and test.
Thanks to everyone who replied, and for all the constructive suggestions and help!
Cheers,
Steve Gabbott
E35/3 Silent Dancer
Gabriola Island B.C.

 

[gabosifat]

Sorry, ignore the other photos, somehow clicked on the inadvertently.
cheers,
Steve

 

[Loren Beach]

Great scenery! Is that near where you live?