Yanmar 3GM30 Stiff Gear Change ?

[akio.kanemoto]

Greetings,

My engine had been sitting idle for several years - lost as another item in the project list... it was a reconditioned "new" engine when I originally "unplugged" it to work on the engine bed some years ago.

I replaced the oil when first "unplugged" and again two months ago when I recomissioned it.. and religiously turned it over by hand now and then in the meantime.

Sure enough, two months ago, it fired right back up, worked perfectly. I ran it for an hour or so (not in gear, but did rev it at the end to blow the carbon out if any).

I then had to disconnect it again due to an air leak in the fuel system, but since then, no use.

Having just reconnected everything yesterday, I noticed that the gear shift lever on the gearbox was quite stiff. After moving it back and forth a few times, it moved a bit easier, but still not as smooth as it used to be only two months ago.

Specifically, when going from NEUTRAL to FWD and again to NEUTRAL then FWD again, it's smooth.

However, when going from FWD through to NEUTRAL and then BACK, the clicking into BACK is difficult. Likewise when going from BACK through NEUTRAL, clicking into FWD is difficult.

Going from either FWD or BACK into NEUTRAL is not a problem.

Going from NEUTRAL, to FWD or BACK is fine.

As above, the main problem is going from one direction to the other, passing NEUTRAL in the middle.

The transmission oil is full and has always been kept that way.

The engine only has 38 hours on it since I bought it.

Any thoughts?

Thank you muchly in advance and looking forward to your collective wisdom!

[Badsanta]

If it is instaled it could be the shift cable.

[perchance]

Originally Posted by Badsanta

If it is instaled it could be the shift cable.

A good place to start. Disconnect the cable at the tranny and shift from there to see if that isolates it.

[Chief Engineer]

Check and see if there are any cable clamps on the shifter cable

[four winds]

Hello, you stated, " I noticed that the gear shift lever on the gearbox was quite stiff."

To me that implies the cable was removed from the trans at this time. But if not, removing the cable and testing the lever only will narrow it down for you as stated. That's the "half split" method in troubleshooting. If the lever is not stiff then it must be in the cable setup.

Also, you stated it wasn't like this two months ago, and you have been doing other maintenance on the engine as well. So you need to carefully consider what might have changed during this maintenance. Cable in a different route now, bends have increased, etc. Since you were working on other things something incidental could have happened related to the trans yet went unnoticed since you were actually working on other things.

Of course, most likely nothing changed while you were away for two months.

I just rebuilt the shifter and installed new cables on my 3gm/kanzaki trans. It's not hard to work on if you are inclined to do so.

edit, not sure how that "gear" got hot linked, I didn't do that on purpose.

[akio.kanemoto]

Thanks for the replies. Greatly appreciated. As Four Winds surmized, yes, I already disconnected the cable and am referring to the shift lever on the gearbox itself.

Any thoughts about common problems? Rust? Something internal? Spray WD40 and hope?