Yanmar Neutral

[gmjosey]

I have a Yanmar 3QM30. I don't seem to have any neutral. I shift from forward to reverse. When I shift into what I think should be neutral the shaft still turns,but very slowly. I cannot find a point where the shaft stays still.

Is there an adjustment for this ?

[Bash]

welcome to the forum.
Assuming you are not underway, but just sitting in the slip, what happens when you first start up the engine before engaging the transmission?

[S/V Illusion]

Have you checked out the transmission linkage? All you need do is remove the cable to the linkage and check to see if there is an indent between F and R. You might need a wrench or pliers to get sufficient leverage.

[gmjosey]

When I first start the engine,the shaft turns very slowly. usually ahead.

Where is this "indent" you mentioned ?

[S/V Illusion]

I'm assuming you already know there is a neutral position on the pedestal control so I will ignore that as a potential cause. My last comment related to the linkage on the transmission itself where the control cable is connected. It should move freely (once you disconnect the cable) between F-N-R.

[nv5l]

I'm not sure which transmission you have, but I just finished overhauling mine on a Yanmar 3HM, a believe they all work basically the same way. There are 3 shafts, input (connected to the flywheel), output (connected to the shaft/ prop), and and idler (used for reverse).

The gears are always meshed and spin freely on the output shaft, both forward and reverse, obviously in opposite directions. The clutch mechanism floats between the and engages one or the other. You should hear, and feel, a click when you put it into gear -- it's spring loaded. It should also click onto neutral.

In your case, one side may be too tight -- do you have fluid? Since it's a friction clutch with springs, there will always some some pressure, but they should slip freely. Of course, that doesn't mean the won't turn.

Have you tried turning the shaft in neutral with the engine off?

[sailorchic34]

The transmission cover on the typical 3qm30 transmission was or is probably miss aligned. The transmission detent / neutral requires the cover to be installed just so. If not (and yes it looks right even if wrong) the lever floats from forward to reverse with no neutral. Don't ask me how I know ;-). I found it to be quite tricky and required a lot of trial and error to get the **&^%$ thing working again. good luck

[sailorchic34]

BTW the shaft may turn slowly in neutral when the oil is cold, but it should stop of you grab it (use pliers though). That's normal on the older 3QM's..The slow turning is due to oil viscosity. If it still turns with the pliers grabbing it (in Neutral) then the detent might need adjusting.

[gmjosey]

Thanks to all of you.When the engine is off and the shifter is between forward and reverse,I can turn the shaft easily so I guess I don't have any worries.