Removing the Transmission

[Michael Algase]

Was heading out today, and heard a "Bang."  Turned around, and got back to the dock under sail.

When I tested the tranny later, it seemd to work well in both forward and reverse, at least in the slip, and through a fairly wide power range.  When I am moving with any speed, however, and I place it in reverse, I get vibration and grumbling that sounds like cavitation.  When I back from the slip, no problem.  I also notice a small amount of chatter when running, but it is intermittent - sometimes it is there, others it is not.

I have someone coming down tonight to dive down and see if there is propeller damage, but it seems curious that it would be the prop if there was an issue in Reverse but not Forward.  I don't know if there is a shock plate under the bell housing (between the flywheel and the shaft) and whether that could have failed, but it only shows symptoms in reverse

Botoom line here, if I have to pull the transmission, it looks like I have to remove the entire bell housing, which also hosts the rear engine mounts.  That said, the engine has to be pulled from the mounts to remove the transmission / bell housing combination. 

Anyone else done this themselves?  I did engine mounts this spring, so I have an idea of what has to be done to remove the engine, including removing the exhaust riser (otherwise you can't clear the aft engine mounts), but I'd like to avoid having to do this.

Any guidance would be more than welcome . . . .

Michael

[Ron Hill]

Michael : I'm not sure if someone has done this or not - "removing the Xmission with engine still in the boat".  It would seem to me that if you do all of the stuff necessary to change the rear engine mounts by lifting the engine, it would only take a little bit of extra work to remove the bell housing/transmission and that damper plate.

Look on the INTERNET and you'll find a bunch of places that rebuild or have rebuilt Hurth transmissions for you to swap out.  One thing that you might think about is going for the Hurth 100 rather than the 50 transmission.  It's a heavier duty Xmission and you have the extra 1 " of depth necessary to accommodate the 100.  Anyway it's a thought. 
Good luck and keep us posted.    

[Stu Jackson]

Mike

Sorry to hear about your troubles.  FYI, the C36s have experienced quite a bit of trouble with their transmissions -- seems like they got a bad bunch from Hurth.  I suggest you spend some time at www.catalina36.org on their message board and see if you can learn anything that may help you in terms of access and removal.  While some had been taken care of by dealers, I seem to remember that some owners did the work themselves.  The engines and transmissions are the same in both boats, although their access is somewhat different.  There was a recent C36 thread referring back to Ron's Projects post (http://www.c34.org/projects/projects-engine-mount-replacement.html) on our site, which also included discussions about engine mounts.

[skip]

Have the diver check the zincs too....May be a zinc that has partiallly been thrown off.   Had similar experience a few years back, including the bang.   It finally went away.     When I pulled boat at end of the year I was minus a zinc.

[Dave DeAre]

Michael,
I recently replaced the Hurth transmission on my 2002 34 with an M35B engine. It was relatively easy. First I removed the entire engine cover assembly in the aft cabin to better access the transmission. Next I disconnected the coupling, pushed the coupling and shaft all the way aft. disconnected the linkage and then removed the transmission bolts. Hardest part was "tacking" the transmission out of the bellhousing. Replacement was the reverse. My alignment was good both before and after the change so nothing was done with engine mounts. The entire job took about 3-4 hours. (a long afternoon) Works fine now!
Dave

[Ron Hill]

Dave : You have a differant engine and apparently it's easy to remove the Xmission - not so easy on an M25XP.

Stu : The C36 and C34 have the same engine/transmission in 1987 thru 1991.  It's either the "luck of the draw" or C36 owners are harder on transmissions than C34 owners!!