1979 MainShip 34 Trans is TOAST!!!

[TaylorFam]

So after going back and forth in the purchase of the boat , we now have taken ownership.

After 14 days on the hard, lots of projects were completed.

Stainless shaft
Coupling
mid bearing
cutless
stuffing box

Re-sealed alots

Hoses and clamps replaced.

Fuel injector line leak fixed

Extra fuel filter gasket removed... LOL

Fluids changed and now splash time...

14 days worth of fun, sleeping aboard the boat, 14 hour days worth of fun every day...

Now she's ready for the 10 hour trip to relocate her to Long Beach, Ca.

After 5 hours approx. 7 miles from the shoreline, beautiful cruising @ 2000 RPM seeing 9kts on 1-3 swells @ probably 12 seconds, she started screaming I pulled back the throttle, and she dropped out of gear. Well crapo I said, thinking this must be the trans. as I opened the Salon floor I could tell the engine was being pulled down like slight surge. I then shut down the engine. looked at the trans and thought, that looks pretty hot! Grabbed a bottle of water and pouring a small amount onto the trans showed me that I should have brought along a steak because the trans could have cooked a nice medium/rare Rib-eye.

Called for a Tow

Waiting maybe 10 minute I checked the fluid nothing on the dip stick, I poured some fluid in her, and fired her up. She ran about 4-5 knots @ 1100 RPM actually impressed, we headed towards shore to meet the Tow boat...

Now that the story is told, now the next day, Today...

I found out that our Transmission is the bastard child in the line up. Borg Warner never did have much success with the 72c 2.10:1 transmission 1018-008R Being that, it didn't have a center shaft support bearing. They in fact put the cooler fluid return on top of the reduction housing for the reason that the reduction gears were getting so hot! That was their attempt to aid the poor design! Being that these would last as long as they did is surprising, considering they didn't offer an alarm or evening a Temp gauge from factory...

Now to the quest of suggestions... Knowing the 2.10 is the only trans in the line up, that doesn't have that center support bearing for shaft, Im being told that we should switch to 1.91:1 trans and change to wheel to LH rotation, or the 2.57:1 and change the RH prop size.

Im seeking any help or advice.

I'll just be over here banging my head against the nearest cabinet door.

 

[Gdavid]

Sorry to hear of your troubles

Make sure your transmission is standard rotation. On many of the early Mainship 34, the Perkins flywheel turned clockwise when viewed from aft, which is considered to be "contra" rotation. For these the transmission is not a reversing gear, it is a reduction gear that only reverses the direction for reverse gear. You can identify what rotation the transmission is made for my the orientation of the pump (once removed from the bell housing). Fortunately these transmissions were pretty common because gas engines where commonly set up for opposite rotation back in the day. A used 72c can usually be found in working order around $500-700 (at least on the east coast) unfortunately the back end of the engine needs to be supported to remove the transmission.

I usually cruise my old Mainship around 1700-1800 rpm for about 7-7.5 knots, it is quieter and not that much slower than 2000rpm.

 

[rslifkin]

For these the transmission is not a reversing gear, it is a reduction gear that only reverses the direction for reverse gear.

For the Velvet Drive 72C (not the CR2 version) most reduction ratios spin the output shaft the same direction as the input with one exception. The 1.88:1 ratio spins the output opposite of the input. All other ratios (including 1.91) spin the same as input. So switching from 2.1 to 1.91 or 2.57 ratio won't require a prop direction change, but it will require a change in prop size (going down to 1.91 will need less pitch, 2.57 will need more pitch, and either may also want a diameter change).

 

[Gdavid]

For the Velvet Drive 72C (not the CR2 version) most reduction ratios spin the output shaft the same direction as the input with one exception. The 1.88:1 ratio spins the output opposite of the input. All other ratios (including 1.91) spin the same as input. So switching from 2.1 to 1.91 or 2.57 ratio won't require a prop direction change, but it will require a change in prop size (going down to 1.91 will need less pitch, 2.57 will need more pitch, and either may also want a diameter change.

Pardon, my ignorance, thanks for the details.

 

[TaylorFam]

Sorry to hear of your troubles

Make sure your transmission is standard rotation. On many of the early Mainship 34, the Perkins flywheel turned clockwise when viewed from aft, which is considered to be "contra" rotation. For these the transmission is not a reversing gear, it is a reduction gear that only reverses the direction for reverse gear. You can identify what rotation the transmission is made for my the orientation of the pump (once removed from the bell housing). Fortunately these transmissions were pretty common because gas engines where commonly set up for opposite rotation back in the day. A used 72c can usually be found in working order around $500-700 (at least on the east coast) unfortunately the back end of the engine needs to be supported to remove the transmission.

I usually cruise my old Mainship around 1700-1800 rpm for about 7-7.5 knots, it is quieter and not that much slower than 2000rpm.

Thank you for that input, after all the work and crap day yesterday. I can't recall the engine rotation. I will be going back to the boat tomorrow evening . I live 1.75 hours away from where it is now.

Learning how to look at a boat engine is confusing, cars and airplanes are my thing. Its all from operators view, front the drivers seat.

If I had to guess, The engine turns Starboard, which would be Contra as you stated. Which is Typical if there is a typical or traditional without other than being stated??

Only having about 3 hours on the boat 1600-1800 RPM was my normal range before the repairs. 2000 Felt so good. Factory suggestions say the max is 2800 and cruising should no more than 80% of that (2240) So Figured with things where they should be, 2000 wouldn't be a push.

Definitely 1800 would be my Norm. But my 10 hour trip was not an adventure, it was a mission, so I guess I was being greedy trying to cover some ground, or water...

 

[TaylorFam]

For the Velvet Drive 72C (not the CR2 version) most reduction ratios spin the output shaft the same direction as the input with one exception. The 1.88:1 ratio spins the output opposite of the input. All other ratios (including 1.91) spin the same as input. So switching from 2.1 to 1.91 or 2.57 ratio won't require a prop direction change, but it will require a change in prop size (going down to 1.91 will need less pitch, 2.57 will need more pitch, and either may also want a diameter change).

Not to question you, but I spent all morning so far on the phone, Both experts Im working with, stated the same thing the 1.91:1 is LH and my shaft is spinning Starboard for sure... Meaning I would need a LH prop. So are you suggesting there is mix up somewhere in the communication??

 

[TaylorFam]

Also, if I were to go with the 1.91:1 from the 2.10:1 what is the common prop size and pitch to go with?? As someone said after 1978 MainShip would use the 1.91:1 commonly, so that knowledge should out there...

 

[rslifkin]

Not to question you, but I spent all morning so far on the phone, Both experts Im working with, stated the same thing the 1.91:1 is LH and my shaft is spinning Starboard for sure... Meaning I would need a LH prop. So are you suggesting there is mix up somewhere in the communication??

I just did a little more digging to confirm. It looks like the 1.91 ratio is reversed (output direction opposite of input) like the 1.88. The manuals I was finding initially were newer and didn't mention the 1.91 ratio at all, but I found an older one I had around that mentions both. Looks like the 1.91 ratio was replaced with 1.88 at some point due to a revision in the reduction gearing, but both of them rotate opposite.

 

[TaylorFam]

I just did a little more digging to confirm. It looks like the 1.91 ratio is reversed (output direction opposite of input) like the 1.88. The manuals I was finding initially were newer and didn't mention the 1.91 ratio at all, but I found an older one I had around that mentions both. Looks like the 1.91 ratio was replaced with 1.88 at some point due to a revision in the reduction gearing, but both of them rotate opposite.

Just called Jim @ Basic power again, and he says Perkins never made a RH engine. Being that my Transmission is turning Starboard at the prop when put in forward, Yes I have pictures and videos showing this. So now, He's thinking this boat is reverse linked. Meaning someone switched the linkage at the trans.

All because the trans I showed him I have, is for a LH engine, so he said how is the boat going to forward when put into forward...

IDK, This is making me feel really stupid! Either that or why in the world anyone do this to a boat?

 

[rslifkin]

Any of the Velvet Drive 72C models can be used with either an LH or RH engine, there's no such thing as an LH or RH trans (although the number will tell you which way it was originally configured). You have to change how the pump is clocked, but once that's done, the trans doesn't care which way it's spinning. And the output shaft will still rotate the same direction as the input (or opposite for 1.88/1.91).

Now, if it's had the F and R positions switched at the shifter, that's a death sentence for a Velvet Drive. Reverse isn't as strong as forward, so the trans will end up slipping and failing. On top of that, the 72C has an additional 1.1:1 reduction in reverse, so the forward and reverse ratios are different.

The best way to confirm what's going on is to start up the engine and note which direction it's spinning.

 

[Jeff F]

Perkins made both RH and LH engines, and Mainship used them interchangeably in the early 34s.

First step is knowing for sure which engine you have.

 

[Jeff F]

Got a photo showing the prop installed? The 2.1 didn't reverse the rotation, but was rotation specific, unlike the other reduction gears. So VD made the 2.1 in two versions depending on rotation.

 

[lwarden]

Sorry to hear of all the trauma @TaylorFam, can't say I'm surprised based on the PO of that boat. Still, you are making progress and will have it sorted out sooner than later.

@Jeff F picture in post 9 appears to show a RH prop.

 

[TaylorFam]

Any of the Velvet Drive 72C models can be used with either an LH or RH engine, there's no such thing as an LH or RH trans (although the number will tell you which way it was originally configured). You have to change how the pump is clocked, but once that's done, the trans doesn't care which way it's spinning. And the output shaft will still rotate the same direction as the input (or opposite for 1.88/1.91).

Now, if it's had the F and R positions switched at the shifter, that's a death sentence for a Velvet Drive. Reverse isn't as strong as forward, so the trans will end up slipping and failing. On top of that, the 72C has an additional 1.1:1 reduction in reverse, so the forward and reverse ratios are different.

The best way to confirm what's going on is to start up the engine and note which direction it's spinning.

Well, if thats true I think that sucks. I read previous threads where Jay said he repowered because the RH engine needs parts that are flat out not made or supported anymore... But to stay on topic, idk what to do until I get back to the boat.

So at this point, I'm in search for what size and pitch prop I need to be searching to go with the 1.91:1 Trans, seeing that this trans is as good as a boat anchor now...

 

[lwarden]

It's hard to believe it was a 72C running backwards in the forward propulsion. The reverse gear with the additional gear reduction is usually pretty noisy IIRC and you would think if it were running 2000 RPM it would put up a god awful racket (before it died and early death).

 

[Jeff F]

Any of the Velvet Drive 72C models can be used with either an LH or RH engine, there's no such thing as an LH or RH trans

The 2.1 is the exception to this rule. I've pointed this out before here and supplied supporting documentation.

 

[TaylorFam]

Sorry to hear of all the trauma @TaylorFam, can't say I'm surprised based on the PO of that boat. Still, you are making progress and will have it sorted out sooner than later.

@Jeff F picture in post 9 appears to show a RH prop.

************Off Topic! You remember what she did look like. What do you think after 4 Days of Polishing, new boot strap paint, and a bottom job.

 

[TaylorFam]

The 2.1 is the exception to this rule. I've pointed this out before here and supplied supporting documentation.

Please provide the thread.

Thx Jeff.

 

[rslifkin]

The 2.1 is the exception to this rule. I've pointed this out before here and supplied supporting documentation.

Thanks for picking up on that. It's not presented in an obvious way in most of the documentation, but I'm sure it's buried in there somewhere. Now that it's been mentioned that does stick in my mind, but I didn't come across it in today's digging through the book.

 

[lwarden]

************Off Topic! You remember what she did look like. What do you think after 4 Days of Polishing, new boot strap paint, and a bottom job.

Wow Craig, can't believe that is the same boat! Usually, when you give a neglected boat some love like that it's good karma and it loves you back. Hopefully after sorting the transmission out it proves to be reliable and your family enjoys it. Seems it needs a bit more love....

You are in good hands here technically, you have the "pros from Dover" on this thread.

 

[Jeff F]

Please provide the thread.

Thx Jeff.

Probably 5+ years ago. The RH version was a rare bird, and you're not likely to find a replacement.

Are you sure yours is toast? If the reduction gear is ok the rest can usually be easily and cheaply rebuilt.

I've had hands on experience. Had a M34 and went through a couple of engine/trans combos.

On the early 34s prop clearance against the hull is marginal. If you do move to a smaller reduction gear I'd suggest reducing pitch on the existing prop.

Oops, meant to say diameter.

 

[Jeff F]

Thanks for picking up on that. It's not presented in an obvious way in most of the documentation, but I'm sure it's buried in there somewhere. Now that it's been mentioned that does stick in my mind, but I didn't come across it in today's digging through the book.

It's obscure. I only tracked it down because I had one, and slowly ground down the thrust bearing using it behind a LH engine

 

[High Wire]

You have good eyes if you can tell the photo in post 9 is RH!
To the OP, RH prop is the prop spins Clockwise in Forward when looking from behind.
Same convention with engines, RH engine Crankshaft spins Clockwise when looking from behind. So RH engine crankshaft spins CCW when looking from the front. Easy to screw this up so write it down or better yet, take a video.

 

[jleonard]

You should not need to change prop pitch if going from 2.1 to 1.9. That boat needs a 20 x 20 prop. Do NOT go to a 2.57 ratio. You wont be able to pitch it enough and you cannot go bigger in diameter.
Yes I had a “ contra rotating” engine in my 78. It was officially called a CKD engine (Complete Knock Down). It was sent to the states in pieces to avoid tarriffs. I actually bought a spare not running engine so I had parts available. They sold quickly when I repowered.

 

[TaylorFam]

You should not need to change prop pitch if going from 2.1 to 1.9. That boat needs a 20 x 20 prop. Do NOT go to a 2.57 ratio. You wont be able to pitch it enough and you cannot go bigger in diameter.
Yes I had a “ contra rotating” engine in my 78. It was officially called a CKD engine (Complete Knock Down). It was sent to the states in pieces to avoid tarriffs. I actually bought a spare not running engine so I had parts available. They sold quickly when I repowered.

Hey Jay any known differences between a 3 or 4 blade prop.

Im being offered a 20x21 3B prop... I need a LH prop for the trans I'm switching to... Should fine??

 

[TaylorFam]

So the finding is...

The engine is a RH Perkins T6.354 (160HP I think...)

The current trans is a 2.10:1 with a RH wheel. Busted unit, but still kinda working, little noisy, LOL. Must have got to at least 500 Degrees.

Im wanting to switch to the 1.91:1 for strength and future repair costs, with a LH wheel. So I need a LH wheel, and a new Dual oil Cooler.

 

[Gdavid]

Mr cool sells the coolers, business is out of Florida and ships quickly

 

[jleonard]

Hey Jay any known differences between a 3 or 4 blade prop.

Im being offered a 20x21 3B prop... I need a LH prop for the trans I'm switching to... Should fine??

That prop should work fine.

 

[TaylorFam]

I Found a LH prop!!! 61 Phone calls around the whole country. TN for the win. Always call, someone has it...