Hurth gearbox - loss of drive in ahead but fine in astern

[Jim Cate]

Harry, thanks for that, and there ain't no strangers on the internet...?

From your initial comments I thought you might have specialist knowledge... thanks for replying with common sense instead!

Cheers,

Jim

[a64pilot]

Look around here for any kind of lubrication questions, especially something that isn't boat specific
- Bob is the Oil Guy

[Tynesider]

Originally Posted by GrahamW

A friend of mine has a 1993 29HP Perkins Perama with a Hurth HBW100 gearbox.

On taking her out one day at the end of last season we noticed a marked d

Does anybody have any suggestions as to what the problem might be?

Thanks for your help.

Hi Graham

Sounds a familiar problem!

Replaced my own Hurth HBW 100 gearbox in 2011 and also a friends in 2012, both were replaced with a ZF10 box as it is a straight swop fit no problem.

However if you check there is a slight difference in the gearbox ratio and I run at slightly less revs than before to achieve the same knots.

One thing no one has mentioned is when you take the gearbox out you should check and consider replacing the thrust or drive plate as this may also be worn and in any case 'IF' it goes at a later date you then have the nice job of taking the gearbox back out again!

You can buy the drive plate direct from the manufacturer R & D MARINE R and D MARINE : Marine Damper Drive Plates

I also spoke at some length to ZF gears and they recommend to prolong the gearbox life to change the oil every 100 hrs and do NOT overfill the gearbox.

Hope this might help

[MarkSF]

Yes there isn't much oil in the gearbox, and 100 hours is not too soon. I changed mine after 300 hours, and it looked horrible - almost black, and it stank. 100 hour intervals for me from now on.

[sailr69]

There is a water cooler available for this tranny, it would be a good buy as it works very well to keep the tranny cool. mounts on the side externally. parts for the hurth are no longer available. the zf is the replacement box

[highseas]

What I read here earlier somewhere is that the Hurth/ZF Box wear from not being used.It seems that bearings sit above transm.fluid in oxygen and they rust,when transmission sits unused.It has been suggested to fill transmission to top when boat in storage.Of course it would have to be drained to correct level before use.

[Sailmonkey]

Originally Posted by highseas

What I read here earlier somewhere is that the Hurth/ZF Box wear from not being used.It seems that bearings sit above transm.fluid in oxygen and they rust,when transmission sits unused.It has been suggested to fill transmission to top when boat in storage.Of course it would have to be drained to correct level before use.

That Is the recommended storage practice, but most failures of these boxes are from clutches slipping and overheating.

[Stu Jackson]

Originally Posted by MarkSF

Yes there isn't much oil in the gearbox, and 100 hours is not too soon. I changed mine after 300 hours, and it looked horrible - almost black, and it stank. 100 hour intervals for me from now on.

Transmission Fluid 101 Transmission Fluid 101

About 150 hours.

[GrahamW]

Many thanks to all who have posted in reply to my original post and follow ups - the advice has been very helpful.

Apologies for the delay in responding - I have been away for a couple of weeks.

It seems that a complete overhaul will be required and I plan on taking the transmission out and sending it off to be done.

I would welcome a bit of advice on just how to deal with removal but will start a separate thread for that.

Regards

Graham