1983 35-3 transmission info and recommendations

[trichards]

Hey Everyone.. Happy New Year!
My Transmission recently died over my Xmas holiday sailing trip to Catalina which made getting home during all these storms quite an adventure.

I'm wondering if anyone would know exactly which transmission came standard in 1983 on the 35-3.. I know its a Hurth and the owners manual that came with the boat lists an Hbw-5 or an hbw-10.. the info plate that is on the actual transmission must be missing. All i can find on mine is the Hurth logo that was made in West Germany (to give you an idea of its age) and a serial number that begins with 05-..

Also wondering if someone who's been through a transmission replacement local to Long beach or LA would have any recommendations for someone to do the removal/install.

I'm looking strongly at replacing this Trans with a Twin Disc Technodrive TMC 40P gearbox as its reasonably priced for a brand new unit and seems like basically a drop in with little modifications..

If anyone has any experience with this or has a good recommendation for a mechanic to do the work i would greatly appreciate it..

 

[Loren Beach]

Is your engine a Universal M-25? That was a 21 HP engine, and the stock trans was likely a Hurth Model 50. There is a lot of info on this site about problems with that particular transmission and the replacement thereof.

 

[Christian Williams]

For the Hurth 50 try (among other threads in "Search"):

Transmission Problems...again. - The Saga Continues

Well, my wife and I had a nice afternoon sail on the Chesapeake Bay on our E32-3 (1987) yesterday and it was particularly nice since we were enjoying the new set of sails that were installed this month. But it was time to sail back to the marina, bring the sails down and motor in....but wait...

ericsonyachts.org

Move Engine to Repair Transmission?

I just starting having problems with our Hurth transmission on our 1989 Ericson 32-3 (popping out of gear at cruising RPM). Tranny fluid has gone to the lab, but looks like a rebuild is required. The mechanic says he'll need to loosen/remove rear engine mounts to lift engine a few inches to...

ericsonyachts.org

 

[trichards]

Is your engine a Universal M-25? That was a 21 HP engine, and the stock trans was likely a Hurth Model 50. There is a lot of info on this site about problems with that particular transmission and the replacement thereof.

Yes, my engine is the universal m-25.. thanks for the info!

 

[Prairie Schooner]

. . .
My Transmission recently died over my Xmas holiday sailing trip to Catalina which made getting home during all these storms quite an adventure.
. . .

Did you have any warning signs with the transmission or was it a sudden failure? The reason I ask is that when we shift to forward our transmission takes a couple-few seconds to engage. When going to reverse it engages immediately. We have the original Hurth.
Thanks,
Jeff

 

[trichards]

Did you have any warning signs with the transmission or was it a sudden failure? The reason I ask is that when we shift to forward our transmission takes a couple-few seconds to engage. When going to reverse it engages immediately. We have the original Hurth.
Thanks,

It did start with some warning signs Jeff.. Right before my 2+ week sailing trip, i decided it would be a good idea to change the trans fluid as it hadn't been done for almost 2 years by the PO. Everything started ok, but not long into our trip i noticed that while in forward gear the boat wouldn't accelerate past a certain point even though i was increasing the RPM's. In fact it would slow down a bit at higher RPM's.

We got to our anchorage and i did some diagnosing and discovered that the forward would start to slip after about 1800 Rpms and the shaft would actually slow down.. I rechecked the fluid, the level was correct but was already cloudy and darker.. As time went on it became harder and harder to engage forward gear and the slipping would happen sooner. Plus, like you, it would take a few seconds for the forward to engage.

I changed the fluid out again in Avalon hoping (and praying) that i would be able to remedy the problem. I also checked the cable linkage for damage and lubricated the cables, but the problem continued to get worse. The fluid i drained out from my recent change was already cloudy and getting dark.. plus there was a layer of sediment in the bottom of the bottle. I knew that getting home would be a chore without a good working forward gear. So we waited for a decent weather window (right in between the 2 storm systems we had here recently in Socal) and sailed back to Long Beach during a Gale watch. We had to be towed out of the harbor at Avalon by the Harbor Patrol and sail the whole way.. Upon getting home i no longer had any forward propulsion except at idle and had to back all the way into the marina and my slip since reverse still worked normally. Quite an adventure to say the least.. Thankfully this boat sails like a champ and got us home without any incident.

All in all the problem progressed really quickly for us.. My Trans is the original from the boat so its basically 40 years old. Also when changing the fluid i noticed the PO had WAY overfilled the transmission. Its supposed to hold approx. 10 oz's of fluid, and i pulled out almost 20 oz's. This might have contributed to the initial damage. Either way I now need a rebuild or replacement.

Good luck with your Trans.. I hope you're not in the same boat as me.. check your fluid and linkage.

 

[Prairie Schooner]

It did start with some warning signs Jeff.. Right before my 2+ week sailing trip, i decided it would be a good idea to change the trans fluid as it hadn't been done for almost 2 years by the PO. Everything started ok, but not long into our trip i noticed that while in forward gear the boat wouldn't accelerate past a certain point even though i was increasing the RPM's. In fact it would slow down a bit at higher RPM's.

We got to our anchorage and i did some diagnosing and discovered that the forward would start to slip after about 1800 Rpms and the shaft would actually slow down.. I rechecked the fluid, the level was correct but was already cloudy and darker.. As time went on it became harder and harder to engage forward gear and the slipping would happen sooner. Plus, like you, it would take a few seconds for the forward to engage.

I changed the fluid out again in Avalon hoping (and praying) that i would be able to remedy the problem. I also checked the cable linkage for damage and lubricated the cables, but the problem continued to get worse. The fluid i drained out from my recent change was already cloudy and getting dark.. plus there was a layer of sediment in the bottom of the bottle. I knew that getting home would be a chore without a good working forward gear. So we waited for a decent weather window (right in between the 2 storm systems we had here recently in Socal) and sailed back to Long Beach during a Gale watch. We had to be towed out of the harbor at Avalon by the Harbor Patrol and sail the whole way.. Upon getting home i no longer had any forward propulsion except at idle and had to back all the way into the marina and my slip since reverse still worked normally. Quite an adventure to say the least.. Thankfully this boat sails like a champ and got us home without any incident.

All in all the problem progressed really quickly for us.. My Trans is the original from the boat so its basically 40 years old. Also when changing the fluid i noticed the PO had WAY overfilled the transmission. Its supposed to hold approx. 10 oz's of fluid, and i pulled out almost 20 oz's. This might have contributed to the initial damage. Either way I now need a rebuild or replacement.

Good luck with your Trans.. I hope you're not in the same boat as me.. check your fluid and linkage.

Thanks much. This is really helpful and will give us some symptoms to watch for.
Good luck with your next steps!
Jeff

 

[movingcastle]

Thanks much. This is really helpful and will give us some symptoms to watch for.
Good luck with your next steps!
Jeff

Second this! My Universal M-25 also occasionally takes an extra couple beats to engage forward. Reverse is immediate. The boat is new-to-me, and I don't know a thing about the transmission except that my mechanic said it "looks good" after adjusting the cables. Time to investigate and check on that fluid level.

 

[dhill]

Second this! My Universal M-25 also occasionally takes an extra couple beats to engage forward. Reverse is immediate. The boat is new-to-me, and I don't know a thing about the transmission except that my mechanic said it "looks good" after adjusting the cables. Time to investigate and check on that fluid level.

Third this. I have Hurth 50 transmission with the Universal M25XP diesel. I sometimes also have a delay of a few seconds going into forward, but not always. Reverse is always immediate, which is better than the opposite. My fluids look good. Perhaps my cables need some work, but the feel seems good. Sounds like this is a common problem though, albeit with a very limited sample set...

Dave

 

[G Kiba]

I know most of you are going to say that I am nuts. I have actually run into a few of you on this sight that have told me so. But here goes.
I had the same slipping problems with my Hurth transmission (M18). Knowing that I will likely have to replace it, I tried a suggestion from the previous owner and it worked and is still working 3 years later. I replaced the ATF with 30wt motor oil. The transmission is still going strong and I have not seen any problems yet.

 

[Loren Beach]

I know most of you are going to say that I am nuts. I have actually run into a few of you on this sight that have told me so. But here goes.
I had the same slipping problems with my Hurth transmission (M18). Knowing that I will likely have to replace it, I tried a suggestion from the previous owner and it worked and is still working 3 years later. I replaced the ATF with 30wt motor oil. The transmission is still going strong and I have not seen any problems yet.

Nope, you're fine....
You seem (relatively) sane to me, a fellow inmate at the sailing looney bin!

About those transmission clutch facings, it's all about the friction on the surfaces and how they react to the viscosity of hot lube oil. I recall that on our prior pickup truck, there were strong warnings to use only a factory-specified lube in the "viscous limited-slip rear axle". Those axles depend on a calculated amount of "slippage" on some little clutches when one axle starts to spin in low traction situations and the torque has to transfer to the side with more grip. It worked great, I should note. The chemistry of lubricants is quite complicated, was my take on it.
When you find a solution that works for your trans, with the surfaces being worn to some unknown extent in the past, stick with it!

 

[Dave G.]

i decided it would be a good idea to change the trans fluid

What type/brand fluid did you use ? The Hurth trans has very specific fluid requirements according to ZF. Please see attached bulletin from ZF. The schedule you want to use is "04D". I had some chattering in forward when I got my boat and have since used MOBIL DELVAC 1 ATF and so far so good.

 

[Prairie Schooner]

Third this. I have Hurth 50 transmission with the Universal M25XP diesel. I sometimes also have a delay of a few seconds going into forward, but not always. Reverse is always immediate, which is better than the opposite. My fluids look good. Perhaps my cables need some work, but the feel seems good. Sounds like this is a common problem though, albeit with a very limited sample set...

Dave

When we had our engine pulled and reinstalled the mechanic changed the tranny fluid. The cables were adjusted when everything was put back in. We still had the lag shifting to forward. The head mechanic did a sea trial after all the work and was concerned, but not alarmed about it. He said we should continue to monitor it's performance. I'd just assumed we'd have to replace the transmission soon. Grant's suggestion is interesting. I'm going to look into that more. Thanks all for chiming in.

 

[Loren Beach]

We use ATF, with no problems. Matter of fact, our former M25XP (Hurth 50) transmission was using synthetic ATF for over 5 years. I would change it out every other year, and sometimes every year.
It was never discolored when inspected.

 

[Christian Williams]

I am curious what discoloration indicates. Perhaps if not clear it suggests damage?

 

[Dave G.]

Complete ZF/Hurth bulletin for those who want to download.

 

[Frank Langer]

I am curious what discoloration indicates. Perhaps if not clear it suggests damage?

Tranny fluid should be bright cherry red. It turns darker when it overheats or "burns" or is really old. Tiny visible metal particles, sometimes only visible by shining a light into the old fluid, show wear.
Frank

 

[Christian Williams]

Aha. Overheating, burning. Got it.

Truth is, I've never changed the fluid. I measure it on the dipstick against a paper towel, but perhaps that ain't enough. The level doesn't change.

 

[Frank Langer]

Aha. Overheating, burning. Got it.

Truth is, I've never changed the fluid. I measure it on the dipstick against a paper towel, but perhaps that ain't enough. The level doesn't change.

It's important to check the level in case there is a leak. It's also important to check colour (bright red vs. dark purple) and to smell it--it has a very distinctive smell, and smells different when it is burnt. If you smell it after a fluid change you'll know if it is different later.
Most sailors neglect their transmissions, often saying they are sailors not mechanics, or the tranny is hard to reach, or they're just a tiny bit lazy. But maybe that's why there are so many posts about tranny problems in this site. I change my tranny fluid during every 2nd oil change, sometimes more often.
Frank

 

[Pete the Cat]

One thing about Hurth transmissions is that they are sensitive to having the detent of the shift lever in the right place to fully engage it. I had a problem with the clamp for the Morse cable (the one on the transmission itself) slipping just 1/8" that made the thing slip out of gear. If your shift lever does not move the lever on the transmission fully forward and stay there on its own (leaves it just partially engaged)--this can induce a failure. Also, as others have noted this particular transmission should be in neutral or reverse, not forward, when sailing or the discs will wear prematurely. As has been noted elsewhere, the Ericson manual specifies .55l of ATF, while the Hurth specs for the HB50 specify .33 l. A marine mechanic friend who works on these daily says he puts a little extra in and it does not hurt, but I once blew the gaskets off the shift lever of a HB 150 by overfilling, so that can be a problem.