Hurth hbw10 forward gear troubles

[bradpb]

My hurth HBW10 transmission only engages forward when engine in idle.
If i move the selector to forward when engine rpm is above idle speed there is no response, if i keep the leaver engaged and lower the rpm i hear a clunk and propeller turns, i can then increase the rpm and everything acts as normal.

Is this normal, or should i be worried.?
I have changed the fluid, the old fluid was a dark red.

[sanibel sailor]

mine occasionally does that as well. Seems more like a time thing than rpm's. Shifting back to N then to Forward again engages it.

[wsmurdoch]

Here is a link to the manual if you don't have it already.

Boatinfo - Hurth 5 10 20 Service Manual

[Vipe6]

Same here although I initially thought it was my Maxprop that wouldn't turn the blades all the way when engaging forward. Pushing the gear lever into forward gear and trying to push it furhter in one movement will result in no thrust at all. Pushing into forward and then waiting a second or two untill I hear the "clunk" does the trick, after that I can rev the engine as I like. Strange thing is that this is not the case in reverse. Maybe it's because the transmission is tilted backwards and the prop and shaft are "hanging". I have watched the prop after engaging and giving some throttle at once and it definitely turns much slower than when I wait for the transmission to engage. I have gotten used to it and I now take this into account when manoeuvering to engage forward well in time.

[MarkSF]

Well, I'm afraid that behaviour is definitely not normal. You can engage mine at full rpm, and while not a great idea to do so, the manual states that you can do so in an emergency.

I see a rebuilt transmission in your futures.

[bradpb]

Originally Posted by MarkSF

Well, I'm afraid that behaviour is definitely not normal. You can engage mine at full rpm, and while not a great idea to do so, the manual states that you can do so in an emergency.

I see a rebuilt transmission in your futures.

Agreed, a new transmission is in my future, I have already added the item to my boat upgrade cost spreadsheet.

[Stu Jackson]

Have you tried to shift down below at the transmission, to determine if it is the transmission or the cable?

[bradpb]

Originally Posted by Stu Jackson

Have you tried to shift down below at the transmission, to determine if it is the transmission or the cable?

I have not done that yet, I had meant to do that last I was at home ( I work away from home for long periods), but time ran out and I was on a flight back to work.

I just bought the boat in december and the mechanical inspection had first identified the problem - I'm assuming that the mechanic would have identified the cable if it was the issue - I know, I know never assume anything, but he is supposed to be a professional.

[Antares Sky]

Hi checking to see if you got the problem resolved, and if so what it was?

Glen

[bradpb]

Glen, i decided to just buy a new one with a new damper plate.

I plan to cruise to a very remote area on the Pacific Northwest, and having a troublesome transmission sounded nerve racking.

The replacement was a zf12m
Brad

[Vipe6]

I just rebuilt mine. changed the thrust washer and clutch plate for the forward gear. Then, when I started putting it back together I noticed that my installation seems to be set up back to front, i.e. to go forward, reverse gear is used and vice versa. Will be hauling out in May to change the rotation on the Maxprop and also change the side to which the gear cable is connected to the shifter. Anyway, the new parts have done the trick and engaging gears is now instantaneous.

[sanibel sailor]

Originally Posted by Vipe6

I just rebuilt mine. changed the thrust washer and clutch plate for the forward gear. Then, when I started putting it back together I noticed that my installation seems to be set up back to front, i.e. to go forward, reverse gear is used and vice versa. Will be hauling out in May to change the rotation on the Maxprop and also change the side to which the gear cable is connected to the shifter. Anyway, the new parts have done the trick and engaging gears is now instantaneous.

Parts source and cost?

[Ocoast]

Overhaul Kit Master Hurth MArine Transmission HBW 10 150 Late Model [ALT316903A] - $249.95

[Vipe6]

I bought mine at Drinkwaard in Sliedrecht (Holland). Very good service there.