Yanmar 3GM30 Slips when trying to engage in forward

[william24424]

Happens more often when engine is hot. Last year I'd keep in gear through mooring field because drifting in crowded mooring field = not fun. She doesn't skip once engaged. Boat is currently on hard & I'd like problem resolved before spring. My research so far has said.

1) Shift Cable and Linkage Adjustment (Most Common) I'd hope this one is right, seems like easier/cheaper fix.
2) Transmission Oil Issues- Possibly, marina handles engine oil changes, I suppose I could check this even in off-season, maybe taste oil or apply to a salad.
3) Worn Cone Clutch -This seems like a complex repair, engine was built in 1988, I'm' not sure where to start.

Any thoughts or has anyone done this dance before & could summarize the steps. Thank you.

 

[kloudie1]

Unfortunately, troubleshooting that problem is best done in the water where a load can be put on the propeller. You've pretty well got the items to investigate except for the adjustment of the shift plate on the transmission itself.. The manual says to not mess with it so if you don't see evidence of the shift plate moving or having moved, probably best to not mess with that part. The oil required will be listed on a plate on the side of the gearbox.. usually on the starboard side. Your engine may have had either a gearbox that requires straight 30 weight engine oil or it could have a gearbox that requires ATF (automatic transmission fluid) The plate will tell you which.
There is a shop manual for the engine and transmission on this site. Click on "Owner Resources" then on "General Downloads" then scroll down to Yanmar and your engine and gearbox is there.. Good luck.

 

[marcham]

I'm not sure what you mean by "I'd keep in gear through mooring field " ?

What symptoms exactly are you experiencing? Is the driveline slipping? Skipping ? Grinding noises?

Have you disconnected the shift cable and tried to manually shift? Have you observed how the shaft behaves with someone at the controls shifting in and out of gear?
Is the behavior the same switching from neutral to reverse as neutral to forwards?

Do you have the correct type and level of oil in the transmission? (typically a 30W heavy duty engine oil, not a transmission oil). The level is supposed to be checked daily, just like engine oil.

Do you have a folding or fixed prop?

Do you keep the transmission in neutral while sailing with the engine off?

When was the cutlass bearing last replaced?

When was the alignment last checked?

The engine being warm or not should not have any bearing on the function of the transmission, as they are fully independant components. If you let the engine get to operating temperature at the dock (170 ish Farenheit), does the shifting behavior change? Or, does the shifting appear to function differently at the end of the day's sail (that is a difference sequence of events).

Cable end inspection and greasing is an annual inspection. Is there any slop or wear in the linkages ?

I'm a strong proponent of owners doing their own coolant and oil changes. Exhaust elbow and heat exchanger should be serviced annually, but are often overlooked and will cause other serious and expensive issues down the line. It's a great way to know and learn the basics of the engine, keep an eye on things and see things before they become an issue. I see Nigel Calder is now offering an online Diesel course (I have no affiliation) Marine Diesel Engines Maintenance - The Ultimate Guide Archives - BoatHowTo

Short of removing the transmission, it's been my experience that troubleshooting requires the boat to be in the water to account for the load of the propeller when shifting.

 

[jtm]

Its been a long time but ... I'd think that one of the fasteners to you cable linkage either in the pedestal or on the engine side may be loose or lost its fastening screw/bolt. You say it happens when the engine is hot so I'm looking first towards the engine side linkage cable fasteners bc as the engine gets hot it can make the cables flexible enough( and with engine vibration) to allow them to bend out of shape, reducing the push/pull hoid on the tranny lever.
I had something similar happen to me but it was in the pedestal- a cable holder that pinned the cable straight in place to the lever housing. The actual cable, when using the lever, was sometimes not going directly into the cable sleeve but was bending before entering the sleeve bc the holder was loose/not straight. Just remove the compass, and unscrew the lever box bolts and pull up on the box to inspect the pinning of the cable end stem holders.

I'd also check that the prop shaft is firmly pinned ( and thru-wire locked) at the set screws(bolts) into the forward shaft receiver where it connects to the output of the tranny .

 

[william24424]

I keep it in gear when entering mooring field, because if I shift to neutral it might not re engage in forward.

What symptoms exactly are you experiencing? Is the driveline slipping? Skipping ? Grinding noises? Not engaging.

Have you disconnected the shift cable and tried to manually shift? Not yet, my next move

Have you observed how the shaft behaves with someone at the controls shifting in and out of gear? Same spin without engage
Is the behavior the same switching from neutral to reverse as neutral to forwards? No, always goes into reverse

Do you have the correct type and level of oil in the transmission? (typically a 30W heavy duty engine oil, not a transmission oil). Yes, I will double check
The level is supposed to be checked daily, just like engine oil.

Do you have a folding or fixed prop? Folding

Do you keep the transmission in neutral while sailing with the engine off? Reverse when sailing

When was the cutlass bearing last replaced? Two Years ago

When was the alignment last checked? Last year



Cable end inspection and greasing is an annual inspection. Is there any slop or wear in the linkages ? didn't notice

I'm a strong proponent of owners doing their own coolant and oil changes. Exhaust elbow and heat exchanger should be serviced annually, but are often overlooked and will cause other serious and expensive issues down the line. It's a great way to know and learn the basics of the engine, keep an eye on things and see things before they become an issue. I see Nigel Calder is now offering an online Diesel course (I have no affiliation) Marine Diesel Engines Maintenance - The Ultimate Guide Archives - BoatHowTo

Short of removing the transmission, it's been my experience that troubleshooting requires the boat to be in the water to account for the load of the propeller when shifting.
[/QUOTE]

 

[william24424]

Sorry I was out a few days, and really appreciate the input.

 

[marcham]

Good luck with the troubleshooting.

FYI, yanmars with kanzaki transmission require it be left in neutral when sailing, otherwise damage may occur. To fold the prop, go to reverse for 3 sec, then back to neutral.

 

[dlochner]

Max Prop recommends the following procedure for feathering their props.

Mechanical Transmission with mechanical controls:

• Power at 2 to 3 knots in forward.
• Kill the engine with the transmission still engaged in forward. The drag of the mechanical transmission should result in sufficient drag on the shaft for the Max-Prop to feather.
• If your propeller has been greased properly, it will feather in a fraction of a second.
• If the propeller has not yet feathered (shaft still rotates under sail), more drag can be added to the shaft of a mechanical transmission by engaging the transmission in reverse, with the engine OFF (WARNING: engage reverse only after the engine has stopped completely).
• After the Max-Prop has feathered, the transmission can be placed back into neutral.

 

[william24424]

Problem seems to be solved. The gear shift (center frame) wasn't being pulled or pushed into it's proper position, meaning fully forward or fully back. I'm am going to replace the cable, I could adjust/oil cable, but I recently replaced other cables in quadrant and feel that new cable is in order.

 

[marcham]

Something is wrong in the rigging. There should NOT be a lock washer and nut attaching the cable to the shift lever. You're missing the appropriate hardware. There should be a nut that threads onto the control cable threaded rod, it would then have a side pin that goes through the lever, secured by a washer and cotter pin.

See the Yanmar / Kanzaki parts manual. It's similar to the setup for the throttle, except it may not have the spring.

Yes, control cables should be replaced every 20 ish years. The fuel shutoff cable should be lubricated annually (as per Yanmar tech bulletin).

It might be a shadow, but it looks like there's a slot of chafe on the lower fuel line. Is it rubbing on the shift lever?

 

[dlochner]

The end fitting on my Yanmar shift cable is a Quick Release Ball Joint for 3300/33C Cables (10-32). It is made by Sea Star. West Marine carries them, but not in their website. The ball joint allows the cable to move through an arc as it follows the arc of the shift lever.

 

[william24424]

I believe it's a shadow. While we're here, the fuel shutoff cable looks like it can use lube, any type? How should I apply?

 

[marcham]

I use engine oil. I pull out the cable from the sleeve (make sure you have a very clean cut first), then lube it with an oil wetted rag when I reinsert it.

Here's what you should find between the shift lever and control cable:

There are other ways to do it, the main thing is it has to be able to rotate in the shift slot without any resistance. There's a lock nut that secures it onto the thread.