Gearbox advice please

[coenvanwyk]

I got a 15 hp Arona diesel motor for a good price, complete with a Hurth 10-2 gearbox. However the latter had rainwater inside, so it will need a complete rebuild.

Having read what people say about the Hurth I was wondering if it would not be cheaper to get another type of gearbox, say a PRM?

What is considered the best/worst or better/worse gearboxes in this range?

 

[CAPTAIN FANTASTIC]

I had a PRM gearbox on my previous yacht (Bruce Roberts), heavy duty and very good. I have little knowledge of the Hurth gearbox, but if the gearbox is not seized, can you flush it out and try to see whether it works?

 

[Plum]

I got a 15 hp Arona diesel motor for a good price, complete with a Hurth 10-2 gearbox. However the latter had rainwater inside, so it will need a complete rebuild.

Having read what people say about the Hurth I was wondering if it would not be cheaper to get another type of gearbox, say a PRM?

What is considered the best/worst or better/worse gearboxes in this range?

My Hurth gearbox is 27 years old and still good. I agree with the earlier posting, drain and flush with oil then refill with oil and see if it works. What damage do you know of as a result of the water that got in?

Www.solocoastalsailing.co.uk

 

[Tranona]

A TMC 40 is probably the most common gearbox in that HP range as used by Beta and Nanni for example.

 

[Hydrozoan]

My Hurth gearbox is 27 years old and still good. I agree with the earlier posting, drain and flush with oil then refill with oil and see if it works. What damage do you know of as a result of the water that got in?

Www.solocoastalsailing.co.uk

My smaller Hurth at 24 years is fine, too - but when you say 'oil', do you mean ATF? www.ybw.com/forums/showthread.php?349397-Another-Hurth-HBW-100-2R-Question

 

[Brent Swain]

Twin Discs are cheaper than Hurth, and better trannys.

 

[coenvanwyk]

Thank you very much for the comments. The bearings are corroded so will have to be replaced, and I guess the seals should be replaced too. If the bearings do not cost too much I plan to pull it apart. I did flush it with ATF but it still does not want to turn, the reverse gear shaft is stuck. Not completely seized, but the needle bearings are probably damaged.

 

[Plum]

My smaller Hurth at 24 years is fine, too - but when you say 'oil', do you mean ATF? www.ybw.com/forums/showthread.php?349397-Another-Hurth-HBW-100-2R-Question

I used the word 'oil' as a generic term. I use ATF in mine but still refer to it as an oil.

Www.solocoastalsailing.co.uk

 

[Hydrozoan]

I used the word 'oil' as a generic term. I use ATF in mine but still refer to it as an oil.

Www.solocoastalsailing.co.uk

I thought that probable, but best in the context to be clear. Good luck to the OP with the rebuild, or whatever he finally decides.

 

[coenvanwyk]

I have now been able to source the bearings and seals, polished the gears, and am in the process of refitting. Now comes a problem: Where the handbook wants thrust washers (sintered bronze) I have shim washers. Seems the brevious rebuilder screwed up. I can order these from the US at $46or o, god knows what opostage, import duties, and what not will ensue. Where can I get the specifications/measurements of these washers? I can make them out of bronze or brass if I have that. The manual only gives the permissible wear, not the original thickness.

The previous owner says it worked well with the shim washers...

 

[Heckler]

I have now been able to source the bearings and seals, polished the gears, and am in the process of refitting. Now comes a problem: Where the handbook wants thrust washers (sintered bronze) I have shim washers. Seems the brevious rebuilder screwed up. I can order these from the US at $46or o, god knows what opostage, import duties, and what not will ensue. Where can I get the specifications/measurements of these washers? I can make them out of bronze or brass if I have that. The manual only gives the permissible wear, not the original thickness.

The previous owner says it worked well with the shim washers...

Measure the shim washers and use that as a start?

 

[coenvanwyk]

I was tempted to press the output shaft together with the new bearings and the shim washers. However, the washers are thinner than the allowable wear on the thrust washer, and the outer diameter is also less than what looks like the thrust face on the gear. And my press-arrangements are rather primitive so I would prefer not to have to take all apart again. So I was hoping someone could provide me with more accurate dimensions.