Rocinante33
Contributing Partner
Cat,
I don't know how feasable it is to rebuild one. Mine failed and after reading horror stories here, I bit the bullet and spent the big bucks for a new ZF10M to replace my old HBW50. Do a search here for "hurth", and, as I recall, you will find threads about it.
Which Ericson (and what vintage) do you have?
I don't know how feasable it is to rebuild one. Mine failed and after reading horror stories here, I bit the bullet and spent the big bucks for a new ZF10M to replace my old HBW50. Do a search here for "hurth", and, as I recall, you will find threads about it.
Which Ericson (and what vintage) do you have?
mherrcat
Contributing Partner
The boat is a 1985 30+
The transmission is a HBW50 and seems to be working fine. There are no apparent leaks. I guess at one time there was a lot of spray from the stuffing box because there is a lot of rust on the case and the shaft coupling is pretty solidy rusted.
The reason I ask is that the rubber hose connecting the stuffing box to the shaft log needs to be replaced soon and I believe that will require removing the shaft coupling. I figured if we're going to that much trouble removing things it might be worth putting a new transmission in at the same time.
There was an almost new ZF5M for sale here recently that needed an output seal, which would mean completely disassembling the unit to replace, but I was just thinking...
The transmission is a HBW50 and seems to be working fine. There are no apparent leaks. I guess at one time there was a lot of spray from the stuffing box because there is a lot of rust on the case and the shaft coupling is pretty solidy rusted.
The reason I ask is that the rubber hose connecting the stuffing box to the shaft log needs to be replaced soon and I believe that will require removing the shaft coupling. I figured if we're going to that much trouble removing things it might be worth putting a new transmission in at the same time.
There was an almost new ZF5M for sale here recently that needed an output seal, which would mean completely disassembling the unit to replace, but I was just thinking...
Tranny
I replaced my trans last fall.
I'm pretty much mechanically inclined and there isn't much I can't fix and I suppose if I got into the trans I'd figure it out but at first look I'd say it's pretty complicated. There's lots of disks and shims and such that all need to be assembled on the various shafts in their proper orientation, clearance, tension, etc.
I wouldn't bother with it but if you have experience with such devices maybe you'd look at it differently. I'd guess that having done one or two with guidance and supervision of someone knowledgeable, doing one on my own wouldn't be so bad.
It's a fairly significant piece of hardware that I wouldn't want to fail at the wrong time just because I didn't space a shim correctly however so I chose a new one.
I replaced my trans last fall.
I'm pretty much mechanically inclined and there isn't much I can't fix and I suppose if I got into the trans I'd figure it out but at first look I'd say it's pretty complicated. There's lots of disks and shims and such that all need to be assembled on the various shafts in their proper orientation, clearance, tension, etc.
I wouldn't bother with it but if you have experience with such devices maybe you'd look at it differently. I'd guess that having done one or two with guidance and supervision of someone knowledgeable, doing one on my own wouldn't be so bad.
It's a fairly significant piece of hardware that I wouldn't want to fail at the wrong time just because I didn't space a shim correctly however so I chose a new one.
Trans
I commented on the other trans/ZF10 thread.
On my 5432, the gearbox is bolted to the bell housing from inside the bell housing so the whole thing has to be removed as a unit. The good news is that while the mechanic was in there, he was able to replace the rear main seal and the dampener plate.
The new ZF10 bolted right up without modification. BUT because the new gearbox is bigger, the engine had to be moved forward along with other mods detailed in my other post.
I don't think the shaft needs to be removed but I did remove it on mine because I replaced the shaft, the coupling, PSS Shaft Seal and cutlass bearing while we were at it.
If yours is working fine, I'd just service it and forget it. When mine finally gave up, we were 10 miles from our haul out facility on a protected inland water way. The boat just kept slowing down even though engine rpm remained the same. We were able to rig our dinghy (10.5 ft with a 15hp Yamaha) for an alongside tow. In this configuration we were able to make 5.5 knots controlling the outboard motor from the deck of our E38 via a tiller extension.
Good Luck with it!
I commented on the other trans/ZF10 thread.
On my 5432, the gearbox is bolted to the bell housing from inside the bell housing so the whole thing has to be removed as a unit. The good news is that while the mechanic was in there, he was able to replace the rear main seal and the dampener plate.
The new ZF10 bolted right up without modification. BUT because the new gearbox is bigger, the engine had to be moved forward along with other mods detailed in my other post.
I don't think the shaft needs to be removed but I did remove it on mine because I replaced the shaft, the coupling, PSS Shaft Seal and cutlass bearing while we were at it.
If yours is working fine, I'd just service it and forget it. When mine finally gave up, we were 10 miles from our haul out facility on a protected inland water way. The boat just kept slowing down even though engine rpm remained the same. We were able to rig our dinghy (10.5 ft with a 15hp Yamaha) for an alongside tow. In this configuration we were able to make 5.5 knots controlling the outboard motor from the deck of our E38 via a tiller extension.
Good Luck with it!
Bell Housing
Yes once the bell housing is unbolted from the engine, you can access the transmission bolts inside the bell housing. The new transmission will bolt up to the old bell housing and then the whole assembly reinstalled on the engine.
Yes once the bell housing is unbolted from the engine, you can access the transmission bolts inside the bell housing. The new transmission will bolt up to the old bell housing and then the whole assembly reinstalled on the engine.
My ZF10 Rebuild Failed
I went to a lot of work and rebuilt my leaking ZF10M. Followed overhaul manual to the letter and shimmed it to a tee. The bearing shimming is easy. The clutch stack shimming is where I went astray. The book values allowed too much play and after 50 hrs it slipped. So after $500 in parts and a failed tranny I followed the advice of the local marine tranny shop and bought a new ZF10M. Shop said they don't bother rebuilding small Hurths.
If you do decide to put in a ZF10 to replace the ZF5 perhaps you can just slide the prop shaft aft the required inch or so instead of moving the engine. Alignment should be easy then. That is what a PO did in our boat. But if it were me and the ZF5 works OK and does not leak too much I would clean it up and keep on truckin.
I went to a lot of work and rebuilt my leaking ZF10M. Followed overhaul manual to the letter and shimmed it to a tee. The bearing shimming is easy. The clutch stack shimming is where I went astray. The book values allowed too much play and after 50 hrs it slipped. So after $500 in parts and a failed tranny I followed the advice of the local marine tranny shop and bought a new ZF10M. Shop said they don't bother rebuilding small Hurths.
If you do decide to put in a ZF10 to replace the ZF5 perhaps you can just slide the prop shaft aft the required inch or so instead of moving the engine. Alignment should be easy then. That is what a PO did in our boat. But if it were me and the ZF5 works OK and does not leak too much I would clean it up and keep on truckin.
Rocinante33
Contributing Partner
Cat,
If you decide to rebuild, let me know if you want a rebuildable unit to work on. I would sell it to you for a minimal fee.
If you decide to rebuild, let me know if you want a rebuildable unit to work on. I would sell it to you for a minimal fee.
mherrcat
Contributing Partner
Thanks for all the info.
I think for now may stick with the current Hurth HBW50. On the E30+ there is very little space, maybe 1" or 1 1/2" between the shaft coupling and the stuffing box. The ZF10M would eat up that space and probably require moving the engine so that the stuffing box could still be accessed for repacking. The idea of cutting down the shaft log is kind of scary. It doesn't seem like there is that much to cut!
If I can get the old rusted shaft coupling replaced and the stuffing box refurbished with new hose connection I think I would be happy for a while.
(Still, a shiny new ZF10M...)
I think for now may stick with the current Hurth HBW50. On the E30+ there is very little space, maybe 1" or 1 1/2" between the shaft coupling and the stuffing box. The ZF10M would eat up that space and probably require moving the engine so that the stuffing box could still be accessed for repacking. The idea of cutting down the shaft log is kind of scary. It doesn't seem like there is that much to cut!
If I can get the old rusted shaft coupling replaced and the stuffing box refurbished with new hose connection I think I would be happy for a while.
(Still, a shiny new ZF10M...)
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