Catalina 34

General Activities => Main Message Board => Topic started by: dhagen on June 28, 2020, 12:17:46 PM

Title: Transmission failure
Post by: dhagen on June 28, 2020, 12:17:46 PM
I changed the transmission fluid on my 2001 C34 MkII last fall for the first time.  Until then, it shifted fine.  Then, I had trouble shifting from reverse to forward.  It would take a few seconds before it shifted.  If I advanced the throttle slightly, it would go into gear.  Thursday, I was coming into the slip and the guy next to me backed out in front of me, so I had to quickly shift into reverse and heard a clunk., but the boat went into reverse and then into forward when I shifted back into forward.  Yesterday, we took the boat out, again having a slight  hesitation in going from reverse to forward.  Then, as we were motoring just outside of the marina at about 1800 RPM, there was a clunk and I lost forward and reverse and we had to be towed back in.  The cable is still connected to the transmission, and the lever at the transmission moves fore and aft, but nothing happens at the prop shaft.  Is it possible that the shift lever at the transmission is loose on the shaft into the transmission?  I couldn't tell yesterday.  Or do I have to replace the transmission, or is there something else that is wrong? Any help would be much appreciated. By the way, the shift lever has always hit the pedestal when shifting into forward, but no trouble in the 12 years I've owned it until now.
Title: Re: Transmission failure
Post by: Roc on June 28, 2020, 03:49:25 PM
When you check the level of the fluid you are not supposed to thread the dipstick all the way down. You just rest it on top without screwing it in. If you checked the level  by totally screwing in the dipstick you may have under filled the fluid. Since you say this is the first time you changed it my thought is you may have checked the level this way.
Title: Re: Transmission failure
Post by: dhagen on June 28, 2020, 06:47:52 PM
No, I did not screw in the dipstick when checking the level. If anything, there is slightly more fluid than required. I checked it again after I had the problem yesterday.
Title: Re: Transmission failure
Post by: KWKloeber on June 28, 2020, 09:36:53 PM
Yes, It’s possible that the shifter arm is slipping on its shaft. That would be the best of situations.
 20 ft-lbs is the spec on the tension bolt.
Title: Re: Transmission failure
Post by: scgunner on June 29, 2020, 07:03:47 AM
dhagen,

Whenever I have a problem I always start with the easy fix first and hope for the best. In this case I'd start with the shift linkage. I'd disconnect the remote shifter at the trans and see if I could shift it at the trans itself. This can be done in the slip, you should be able to see(prop shaft) and feel if the trans will go into forward and reverse. If it still won't shift properly you're probably going to have to pull the trans.
Title: Re: Transmission failure
Post by: Colonel Butler on June 29, 2020, 09:57:21 AM
With respect to the comment about the shift lever hitting the binnacle... Check which hole on the gearbox shift arm the shift cable is attached to. I had to move mine to the inner radius one to ensure the gearbox shift arm was moving its full range to ensure proper engagement of forward gear. Incomplete engagement could cause undue wear.

I had my transmission out to replace the damper plate this winter. Not too bad of a job.
Title: Re: Transmission failure
Post by: dhagen on June 29, 2020, 11:56:32 AM
I checked the shift arm at the transmission.  When I move it, the shaft turns, so unfortunately, that is not the problem.  I will have to remove the transmission.  Any idea how long of a job that is?  I'm going to have the marina do it, but want to have some idea how long it should take.  I'm assuming that the front of the wood access box can be disassembled with removal of just a few screws Thanks.
Title: Re: Transmission failure
Post by: dhagen on June 29, 2020, 12:04:37 PM
FYI, it is an M35B universal diesel with a ZF 10M/Hurth 100 transmission.
Title: Re: Transmission failure
Post by: Ron Hill on June 29, 2020, 01:12:59 PM
dhag : You should be able to remove the transmission in no more that 2 hours. I'll guess it should be even less than 1 hour.  Just a few bolts!!

A thought
Title: Re: Transmission failure
Post by: Noah on June 29, 2020, 01:47:40 PM
With due respect, (and not being a mechanic), I suspect Ron’s timeframe is overly optimistic and assumes none of the bolts to the coupler, etc. are frozen, and there is nothing else in the way that must be removed such as the heat exchanger, shifting linkage brackets, etc.—and all your stars are aligned.
Title: Re: Transmission failure
Post by: dhagen on June 29, 2020, 06:00:18 PM
Yeah, to me it looks like more than an hour.  There are a few things in the way that will have to be moved to get at it.  But if it is more than 4 hours, I can question why it took so long. Thanks.
Title: Re: Transmission failure
Post by: Noah on June 29, 2020, 07:00:30 PM
Also, remember when calculating this will be a “roundtrip” journey and all will have to be reassembled too. Also maybe involve filling burping coolant if HX is removed. It can help by soaking the coupler bolts/nuts with penetrating oil ahead of time. However, be very careful not to get any oil on the rear transmission seal as I hear it will eat it up. Use a Q-tip to apply. Maybe not an issue if tranny needs rebuilding?
Title: Re: Transmission failure
Post by: Ron Hill on June 30, 2020, 02:52:09 PM
Noah : I had to change out a faulty transmission on an a new M25XPB engine (which is the same as ZF10 as a M35BC). There were 2 of us, but as you know only one person can get down in the aft cabin behind the engine to do the work!
 
I still believe that it only took about an hour - however it was a new engine and all attachments were only a week or so old!   :shock:

A few thoughts


Title: Re: Transmission failure
Post by: dhagen on June 30, 2020, 04:53:55 PM
Marine Parts Source in MI has a new replacement transmission by Baysan Marine that he says is a direct replacement. It is 1/2”-3/4” longer so it would push the prop back that much. Would that be a problem? I think I have that much room at the rudder.
Title: Re: Transmission failure
Post by: Jon W on June 30, 2020, 05:03:17 PM
You gotta love suppliers. It’s a direct replacement, except it’s a little bit different.  :shock:
Title: Re: Transmission failure
Post by: Noah on June 30, 2020, 05:16:43 PM
If you go for that transmission you might as well shorten your shaft at the same time. Minimal added cost and would also be an opportunity to inspect, polish and true. Ideally the prop should be 1in. behind the strut.
Title: Re: Transmission failure
Post by: KWKloeber on June 30, 2020, 05:22:48 PM
Dh

What are the particulars - model # or MPS item # etc?
Title: Re: Transmission failure
Post by: dhagen on July 01, 2020, 07:48:40 AM
It is a Baysan BMT-M30-2.00.  If I have the shaft shortened, I would have to have the boat hauled, which I don't want to do at this point.  Maybe when It is hauled for the winter.
Title: Re: Transmission failure
Post by: Dave DeAre on July 01, 2020, 12:05:26 PM
I replaced the transmission on my 2002. Yes, the aft cabin must be empty, the "box" can be easily removed with 4 or 6 screws. Coupling disconnected and the shaft pushed back for clearance. Linkage disconnected and then the transmission bolts are accessed with a socket wrench and extension. Job is easy, unless any fasteners are corroded or frozen. It probably took me 4 hours total to do the job. Replace the damper at the same time.
Title: Re: Transmission failure
Post by: Ron Hill on July 01, 2020, 02:51:28 PM
dhagen : Rule of thumb - the prop distance from the strut should be one shaft diameter (1")

A thought
Title: Re: Transmission failure
Post by: Bill Shreeves on July 01, 2020, 07:46:06 PM
dhag, I replaced my damper plate, tranny (actually a gearbox not a tranny I'm told), coupling, stuffing box, cutlass prop & shaft myself a few years ago.  The gearbox wasn't that hard.  Most everyone will tell you to always replace the damper plate when you remove the gearbox.  The cost will likely be all parts because it takes little time to actually replace and I'd highly recommend it while they're in there.  Also expect to pay labor for aligning the engine. If the gearbox is only longer and not lower there shouldn't be much if it was reasonably aligned before.  If it hasn't been aligned in a long time it might take more time because the mounts settle over years I'm told.
Title: Re: Transmission failure
Post by: dhagen on July 02, 2020, 07:38:47 AM
I removed the cabinetry yesterday. It was more than 4 screws, more like 8. The key trick is trying to figure out which eight!   And then getting at them through the opening in the top.
Title: Re: Transmission failure
Post by: dhagen on July 22, 2020, 06:52:52 AM
It turns out the damper plate had broken into 3 pieces.  Replaced it and it is good to go.
Title: Re: Transmission failure
Post by: Jon W on July 22, 2020, 07:45:52 AM
Several posts on damper plate problems lately. I’m wondering if this is a problem I need to start saving for. :cry4` What causes the damper plate to fail, or break into multiple pieces? How many engine hours do you have? Thanks for the help.
Title: Re: Transmission failure
Post by: Ron Hill on July 23, 2020, 02:33:54 PM
Guys : When I replaced the damper plate on my old M25XP, I did it as a "just in case" as I had everything out of the boat and was replacing the transmission (Hurth100). That old damper plate was working just fine.  That old engine had almost 5,000 hours on it!!

A thought
Title: Re: Transmission failure
Post by: Ron Hill on July 23, 2020, 02:43:30 PM
Guys : You can shorten the shaft while the boat is in the water, BUT you are cutting away part or all of the keyway!!!

When I did that I had a flexible coupling and didn't use the keyway!



Title: Re: Transmission failure
Post by: dhagen on July 29, 2020, 04:34:43 PM
My engine has about 1000 hours on it, but it is a 2001. My understanding is that on the M35B, it is just a piece of plastic. My guess is after 20 years, the plastic just got brittle and cracked.
Title: Re: Transmission failure
Post by: Ron Hill on July 30, 2020, 02:31:37 PM
dha : No it is not just a piece of plastic!!
 
I'd describe it as an elastomeric connection that the shaft fits into.  On the M25/25XP engines it "looked" like a old clutch plate.
Maybe Ken or Mainsail can give a better description.

A thought