Yanmar 3gm30 F....removing Drive disc

S34 · #1 (**permalink**) 10-11-2010

Gidday,
I removed the trans on the above to clean and check. I have removed the retaining bolts on the drive disc but cannot seem to be able to get purchase on it to remove from flywheel. Can anyone describe how it is done? No mention in the manual.
It would be appreciated.
Thx,
Roly

Faster · #2 (**permalink**) 10-11-2010

Have you looked here? First page has an email link for help..

Second link is Kanzaki, probably of limited help but perhaps you can navigate from there to something useful.

TRANSMISSION TYPES

_è‚‹‰H‹@»ìŠ@ƒ}ƒŠƒ“ƒMƒ„

S34 · #3 (**permalink**) 10-12-2010

Email link seems to be defunct.It Was returned undelivered.
I am going to try a bolt head shoulder thru the spline, attached to a plate
bridging the raised edges of the outside face of the flywheel. Crank a nut down on the plate
to put pressure on the inside face of the drive disc assembly. FWIW, I will post back with results. Yanmar probably have a tool for this.

kolbn · #4 (**permalink**) 10-28-2010

Did you ever get the damper plate off of the flywheel?

S34 · #5 (**permalink**) 10-29-2010

Not yet. I have had to shelve the project for a few weeks. Will report back when I have had time to get into it.

JimsCAL · #6 (**permalink**) 10-31-2010

I have a 3GM30F and have the maintenace manual. Took a look at the transmission section when I was on the boat today. The page on the damper plate had no special instruction on removal. Looks like just 6 standard bolts. Sounds like you just can't bust them loose. Did you consider trying an impact driver?

S34 · #7 (**permalink**) 11-01-2010

I have already removed the bolts. ( With relative ease)
Don't know how I would use a impact wrench to free the drive damper
from its seat though.

JimsCAL · #8 (**permalink**) 11-01-2010

Sorry, I misundersood. Thought you were having trouble getting the bolts off. That said, the maintenance manual did not say anything specific about getting if off after removing the bolts. From the drawing, it looks like the plate should be free at that point. I'd be tempted to spray it with something like PB Blaster and let that sit for awhile and then try again.

kolbn · #9 (**permalink**) 11-01-2010

Quote:

Originally Posted by JimsCAL

I'd be tempted to spray it with something like PB Blaster and let that sit for awhile and then try again.

Exactly! Try the PB Blaster, spray it good around all edges and bolt holes. Wait an hour and spray it again. As you know, I had the same problem. Did this then put the the smooth end of the breaker bar into the spline (long socket wrench would work) and shook it in all directions (The plate will flex a little) until it popped off (bout 5-10 good minutes).

Good luck, knowing that it can be done helps.

S34 · #10 (**permalink**) 01-03-2011

Finally got the time to attack the motor again. I tried as you guys suggested.
But we don't have PB blaster here. Had to settle for CRC. Wouldn't budge after a day soak. So resorted to the method I was thinking earlier. I had to crank the nut pretty far before it came off. I was worried about it distorting the drive disc
but alls well.

Actually was pretty quick to do it this way. Made a bit of noise tho'.
The trick is to jam the bolt against the spline with a wood plug. This
insures the shoulder of the coach bolt head is making good contact with the back of the spline circumference. Coach bolt was 75mmx8mm.