Transmission issue

[pbyrne]

Came into the fuel dock and shifted into reverse to slow the boat down and to my surprise it increased speed.

After a hair raising, bounce off the fuel dock and a panic stop I had a chance to test things out.

Shifts into forward and that seems normal, but shift into reverse and goes forward as well. There are also some notices that weren't there before.

I'll up load a video to YT ASAP but thought I'd ask you folks now anyways.

[Gulfsailor]

Not sure what transmission you have but if it's a Hurth ZF10 it could be time for a replacement...I hope not. Our Ericson had a ZF10 that went bad. The guys from the factory called them the "1000 hour transmission" because they were known to fail at that many hours.

That being said, we put a brand new (in 2007) ZF10 that was still flawless when we sold the boat last fall (well over 1,000 new hours).

Perhaps it could be a linkage issue. Have someone stand at the helm and shift from forward to reverse while you look at the cable and linkage. It could be that the bracket that holds the cable to the transmission housing came off...

[pbyrne]

Photo of Transmission model and a couple of videos.  I don't see anything wrong with the linkage, but the sounds the transmission/engine is making in neutral is not what it normally sounds like.  Something soungs 'rattley'.

https://youtube.com/shorts/427HSVWaLsk?feature=share
https://youtube.com/shorts/6pg4adHzD8I?feature=share

[pbyrne]

Not sure what transmission you have but if it's a Hurth ZF10 it could be time for a replacement...I hope not. Our Ericson had a ZF10 that went bad. The guys from the factory called them the "1000 hour transmission" because they were known to fail at that many hours.

That being said, we put a brand new (in 2007) ZF10 that was still flawless when we sold the boat last fall (well over 1,000 new hours).

Perhaps it could be a linkage issue. Have someone stand at the helm and shift from forward to reverse while you look at the cable and linkage. It could be that the bracket that holds the cable to the transmission housing came off...

Ironically, the engine has 920 hours logged.  I did exactly what you said, and had my wife shift while I inspected the linkage, and the connections, including the connection to the shaft that goes into the transmission.  They all appeared good to me.

[Stu Jackson]

Checked the fluid level?

[pbyrne]

Checked the fluid level?

Checked in the spring, and was good.  No signs of any leakage.  It was too hot to check, not scortching, just hotter than I was willing to open and take my chances with it on my skin.

[Jim Hardesty]

Oh no.    Transmission problems are one of the things that concerns me. The main reason is I don't know of any inspection or checks that warn of an impending failure.
I would check the fluid for level, color and smell.  Should be light red and not smell burnt, best to check with it against a sample of new fluid (left over from last change).  Then check the cables and cable adjustment that it moves the lever on the transmission correctly.  I believe that's all that can be done without removing the beast. 
One caution, it may work cold at the dock and fail only when it's hot.  The transmission shouldn't get any warmer than the engine block. 
Hope it's an easy fix.
Jim

[pbyrne]

Oh no.    Transmission problems are one of the things that concerns me. The main reason is I don't know of any inspection or checks that warn of an impending failure.
I would check the fluid for level, color and smell.  Should be light red and not smell burnt, best to check with it against a sample of new fluid (left over from last change).  Then check the cables and cable adjustment that it moves the lever on the transmission correctly.  I believe that's all that can be done without removing the beast. 
One caution, it may work cold at the dock and fail only when it's hot.  The transmission shouldn't get any warmer than the engine block. 
Hope it's an easy fix.
Jim

Would bad fluid cause this? The fluid is from last season, but very little hours as we had just moved the boat, and didn't take it out much at all.  Maybe 8 hours? This season to date maybe 20 hours?

I had my wife shift between FWD/REV and I watched all the linkages, including connection from the lever to the shaft into the transmission to make sure the shaft into the transmission itself was moving.  Thing to keep in mind is that it does engage in FWD (and sounds normal) and does go into REV (doesn't sound right) but the boat moves forward in BOTH positions.

There is a variprop 3 blade feathering prop, which maybe that isn't changing pitch?  I didn't think to check the shaft rotation in REV, but in the video (above) there is something very rattel-y that isn't there normally.

What does it take to remove the transmission? The engine hours show 920 hours so this whole thing is very frustrating.

[Dave Spencer]

I removed and replaced my transmission last fall. Here's the write up. https://c34.org/bbs/index.php/topic,11865.msg96487.html#msg96487
I suspect you have an M35B engine that I'm fairly certain has an adapter plate for the transmission. My M35A engine mounts the transmission from inside the bell housing so the engine had to come out to remove the transmission. You may not have to remove the engine to remove your transmission making the job much easier.
I can't imagine how the transmission would operate in forward with the lever on the transmission in the reverse position. I took my old Hurth transmission apart once it was condemned and I recall there is a shifting fork actuated by the shift lever that engages with a shifting sleeve that applies pressure to either the forward or reverse clutch packs. Perhaps the lever to shift fork mechanism is damaged but you'd have to take it apart to determine that. I can't imagine that low oil level or even dirty oil would cause what you're seeing.
Sorry I can't offer any brilliant ideas even though I became very familiar with my transmission last fall.
Good luck with it and let us know how you make out.

[pbyrne]

Do any of these photos help with what the approach would be to remove the transmission?  It's going to have to be a pro that does it.  I live 2 hours away from the boat, and get there every couple of weekends.   I'm not in a position to do the work myself, so anything that I can help rely to the fella who's going to do it would be helpful.

[Ron Hill]

pby : Disconnect the cable from the shifter at the transmission. The with the engine running manually shift to FWD and Reverse and look at the rotation of the shaft. If it is only in one direction (clockwise?) then you need to have someone look at that transmission for possible rebuild!!

A few thoughts

[Gulfsailor]

I know we had to remove the engine to replace ours. After installing the new one, I became absolutely anal about ritually checking the transmission fluid every single time I took out the boat (along with the oil and coolant).

The dipstick on top of the Hurth was easy for me to reach over the Universal M25XP and unscrew. On the MKII, it's more challenging to get to the dipstick.

I suggest you start looking for a replacement (we rebuilt ours and it failed still necessitating the new one). We also replaced the motor mounts while the engine was out.

[pbyrne]

So the mechanic had a look at it.  Initial assessment is that the transmission is nosier in forward than it should be, but shaft rotation was CORRECT.

He was able to reproduce my experience and messed around with it for a bit, and the boat started to go forward and reverse.

Transmission may need some clutches (maybe a damper fix, someone tell me how to tell the difference, its just 'rattely' in forward, but doesn't seem to slip), but at the moment it looks like the PROP may be the issue.

[Dave Spencer]

Hi pbyrne,
The pictures don't help. They don't show the joint between the transmission and the bell housing on the back of the engine. If you can see bolts that look like they will allow you to unbolt the transmission from the back of the engine, the engine doesn't need to come out. If you can't see any bolts, it's mounted from the inside and the engine must come out. I recall there was a good write up about removing the transmission to replace the damper plate without pulling the pack on the C350 website. Here it is.

http://www.catalina350.com/phpBB3/viewtopic.php?t=685

It wasn't applicable to me and may not be to you either but it's worth a look.

[Jim Hardesty]

Would bad fluid cause this?

No.  But dark burned fluid would be a sign of slipping clutches.
Jim