Replacement gearbox for Universal M30

[Quadrille in JB]

Our 1984 O’Day 34 has the original universal M 30 diesel engine. It has always been a little iffy shifting in the forward for the past several years. It has finally died; it will only shift into forward about one out of three times and sometimes it slips in forward. I removed it today.
Does anyone have a source for parts or a replacement for this Hurth HBW5?

[BillKny]

Originally Posted by Quadrille in JB

Our 1984 O’Day 34 has the original universal M 30 diesel engine. It has always been a little iffy shifting in the forward for the past several years. It has finally died; it will only shift into forward about one out of three times and sometimes it slips in forward. I removed it today.
Does anyone have a source for parts or a replacement for this Hurth HBW5?

Hurth was absorbed into ZF marine a number of years ago. The current model matching (I believe) your tranny is a ZF5M. You'll need to chack carefully, there are a number of options that you need to be sure you match.

Some of the best prices, and technical advice on ZF transmissions is from MarineGears.com in Fort Lauderdale.

These transmissions are pretty cheap to buy, and a real PITA to repair.

[oldcal46skipper]

I have been repairing marine gear boxes for over 40 years. It is a waste of $$$ to try to repair this. Get a new ZF for less. I can help. I am in Pensacola, FL

[Sailmonkey]

Don’t repair this, replace it with a twin disc or new zf box

[Alain Croteau]

Try Transmission Marine Inc 800 462 8848 for ZF12. Call Greg at US Marine Service 954 6461429. Both in Ft Lauderdale. I had to replace a Kanzaki on a Yanmar 3jh2. Very good service from both.

[peter loveridge]

I got through 4 zf hurth transmissions, one of which lasted less than 30 hours. Finally saw the light and replaced it with the twin disc equivalent, which is made in Italy. Uses the same bolt holes, so it just drops in . It is marginally bigger and you might have to fiddle a bit with the engine mounts. My mechanic changed in less than 3 hours

[boat driver]

Originally Posted by Quadrille in JB

Our 1984 O’Day 34 has the original universal M 30 diesel engine. It has always been a little iffy shifting in the forward for the past several years. It has finally died; it will only shift into forward about one out of three times and sometimes it slips in forward. I removed it today.
Does anyone have a source for parts or a replacement for this Hurth HBW5?

pm me-
send a picture of the unit-
what is your time frame needed?
I may have one in the depths of storage-

[Alain Croteau]

I believe the ZF 12 M is manufactured in Italy.

[manitu]

Prm gearbox fits too.


.manitu

[jen1722terry]

We recommend the twin disc also.

We had an older M25 with the ZF10 tranny. One lasted about 200 hours. The replacement had to be replaced under warranty at about 90 hours. Decided to sell the engine and tranny shortly thereafter.

Heard good things about the twin disc. The tranny on our new Beta 25 is a different design but so far works very well.

Best of luck.

[Quadrille in JB]

Thanks for all of your replies. I’ll PM the two of you and I’ll contact the recommended companies. BTW does anyone have a name for a twin disc dealer?
Thanks again,
Bill in JB

[patprice]

Originally Posted by manitu

Prm gearbox fits too.


.manitu

Yes I replaced my third ZF10 with a PRM. Had to lift the engine 10mm. Easy.

[Uncle Bob]

Originally Posted by patprice

Yes I replaced my third ZF10 with a PRM. Had to lift the engine 10mm. Easy.

Ditto, out with the hurth, and in with the prm. The PRM is fractionally longer and the controls are on the other side of the box, both easily overcome.

[patprice]

Originally Posted by Uncle Bob

Ditto, out with the hurth, and in with the prm. The PRM is fractionally longer and the controls are on the other side of the box, both easily overcome.

The PRM does rattle a bit at low revs!

[Searles]

Most gearbox rattlesat low rpm are in fact the engine to g box drive plate,if the noise or vibration sceases with a slight increase in rpm it may be the drive plate.anti shock springs slightly worn ,maybe .⛵️⚓️