Transmission problems

[Bfb1115]

Hi all,
I have a 1984 Catalina 30 with a um-25 and hurth hbw-50 transmission. Yesterday I was sailing under power. I noticed eventually that my speed had dropped severely and there was smoke from the transmission.

I let it sit for awhile, removed a cable that burned up because it was laying against the shaft, and re-started the engine. This time I was able to get back to normal speed for about 20 minutes (heading home, no wind) before it began to smoke again. I realized that the shaft was rotating much slower than normal.

I decided to bypass the shift cable and operate the shifter arm manually. After this I was never able to get the shaft to rotate fast enough in the forward direction. I was however, able to operate the boat as normal in reverse. I reversed for another 20 minutes and made it safely to my slip.

This morning I woke up and tested the transmission again. This time, no matter what gear the boat is in, the shaft does not turn at all. I haven't yet tried turning the shaft by hand.

Any thoughts? I'm dreading the prospect of replacing the entire transmission.

 

[Capt jgw]

Sounds like the clutches burned out. You can try changing the trans oil (ATF), but probably the damage has been done. They don't make the Hurth anymore, it was bought out by ZF, and I don't think those are made anymore either. The unit can be rebuilt of you can find the parts, I've seen the kit on eBay at times, intermittently. Also complete used or rebuilt units show up on occasion. The Hurth HBW 5, 50, and ZF 5 are all the same and will fit. A boat salvage yard might have one but I imagine they don't sit on the shelf long, and anything you get that way might be worse than the one you are replacing.

 

[DaveJ]

Sounds like an issue I had last year. I could back out of my slip, but sometimes I couldn't engage forward, but it would work after a couple of attempts. I pulled the transmission, the same one as yours, clutch plates were obviously burned, and ordered the parts and had a friend rebuild it over the winter. Will be launching in a couple of weeks, fingers are crossed......
I ordered the clutch plate kit from Basic Power Industries (part #ALT316750), I also ordered the gasket set(part #ALT316801B). Total was a little over $300.
Everything fit, but I could not do the rebuild myself, it will take an experienced person to do this.
Good luck.

dj

 

[centerline]

there is a problem with some transmissions having the wrong oil in them and smoking the clutch packs.... this was a problem with my boat when I bought it. the servive manual says use only TYPE F TRANSMISSION FLUID.... boldly.

my transmission at full speed would smoke and actually boil fluid out the vent.... and I didnt know why. the bearings ran smooth and without any issues, and when idling around there was never a problem, but when I put power to it, it heated up.... the top cover paint has actually turned from red to brownish.....

after calling tech support to talk to them about the problem, they asked what type of fluid I was using... and I didnt know what the PO used in it, but he said he just serviced it... tech support said type F must be used to insure a good lockup because it does NOT have friction modifiers in it, which can cause slippage.

so I changed it, and ran it a while... it heated up a bit, so I changed it again and and ran it... after three flushes and getting all the friction modifiers changed out and the plates flushed, there is no longer a heat problem at all at any rpm....

in your case, the clutches are too far gone to save, but im sure the parts are available to repair it.... expect around $600 for a set of discs and plates... make sure you do change the plates because the heat has probably warped them.

 

[Bfb1115]

Thanks everybody. I'll be attempting to pull it off today and have a look see.

 

[Bfb1115]

Sounds like an issue I had last year. I could back out of my slip, but sometimes I couldn't engage forward, but it would work after a couple of attempts. I pulled the transmission, the same one as yours, clutch plates were obviously burned, and ordered the parts and had a friend rebuild it over the winter. Will be launching in a couple of weeks, fingers are crossed......
I ordered the clutch plate kit from Basic Power Industries (part #ALT316750), I also ordered the gasket set(part #ALT316801B). Total was a little over $300.
Everything fit, but I could not do the rebuild myself, it will take an experienced person to do this.
Good luck.

dj

Let me know how yours turns out!