Hurth transmission leak?? Pls help!-gctid818933

[Timcup]

Am out for a 10 day cruise on our 1987 38 with 175 hinos and hurth transmissions and I open the lazzarette and find a small spray of tranny fluid coming off the shaft as it comes out of the transmission. I can feel a small amount of fluid on the bottom of the tranny as well so it could be coming from anywhere.

It is only a small amount from a 4 hour cruise at 1500 rpms. Fluid level in tranny the same as when I started. No cooling issues.

Any thoughts? Any issues to leave this until we get back? Have about 15 more hours of run time before we get home.

Thanks!!

[smitty477]

If you are sure there is no extra fluid and its not whiter or foaming you likely have a shaft seal leak.

Make sure it stays topped up for the balance of the trip and maybe fabricate a temporary 'slinger' cover to keep the spray going down only.

I have had good luck turning plastic gallon bottles into temporary slinger covers in the past.

[Timcup]

Thanks smitty! Will do.

[floatyerboat]

I'm curious of the spray. Is this a spray under pressure or tranny fluid flying around from the turning shaft? Aren't all the Hurth's vented so the tranny doesn't build up any pressure? I know my Hurth 360a's on my gas drives had vents that were totally plugged. The spray was coming out of the filler/dipstick under the crush gasket on both transissions and was making one hell of a mess. I yanked both vents and couldn't even blow thru them, cleaned them out and no more mess in the bilge.

[Ruffryder]

Breather clogged by paint or dirt

or Shaft seal faulty

[Jim_Gandee]

+1. Double ck the vent is not plugged then do as Smitty recommends.

[Timcup]

Thanks all, got back from

The trip with minimal leakage. Am back at the boat next week and will check the vent.

Have to pull the manual to see where it is. Any tricks to removing it?

[floatyerboat]

I kind of F'ed mine up taking them out. One came out and the other was stuck. My transmission is a Hurth 360a. They don't make the 360a's anymore.

Here is a picture of the good one. It had a grove on the bottom for a O ring or metal clip. Which means they were probably fastened from inside the transmission.




Attached files

[nile]

Good chances the spray comes from leaking fluid at the rear seal and being centrifugated by the turning shaft. Easy fix by removing the coupler and pulling out the old seal (use small sharp screw driver to tear it off) and smoothly and evenly pushing a new one in.

[Timcup]

Took out one vent plug and the other is stuck. Are these supposed to just pull out? How much force do you have to use? As well the one I got out was plugged. Do they breather from under the mushroom cap top?

[Timcup]

Floatyerboat, mine has the same grove. Think it is an internal c clip or spring hold.

[floatyerboat]

Sorry I was on the boat all day. Yes they breath from under the mushroom. On the second tranny I couldn't get it to pop out but the mushroom cap came off so I cleaned the stem in place and just laid the cap back on the stem and it hasn't come off yet. I wanted to say c clip but the name just wouldn't pop into my head. I twisted a drill bit down through the stems but be careful so you don't drop it. Hopefully its a thin brass c clip and it dropped to the bottom. Either way the burping under the filler cap is gone now. HS design.

There was a lot of dried crud that came out of there.

[Timcup]

Floatyerboat,

Anyone pls correct me if I am wrong, but believe these breather valves were made to be taken out and put back in without taking the tranny off.

Simple push fit.

[floatyerboat]

When I pulled my two vents I realized there was a C ring holding them in place from the inside and wasn't about to pull the transmission to replace the C-ring that probably dropped down inside so after cleaning I dropped the vent back in the hole it came out of and I haven't had any trouble with popping out in 2 years. Put them back in and forget about it. I'd just check it every so often. I found the Hurth 360a and 450 manual online and I will post it here. At the bottom of the manual in the parts list the vent is part # 76. On the diagram it shows part 76 but not how it fastens to the transmission. I was thinking maybe it would be easier to leave them unfastened so every spring they could be pulled and cleaned.

Sorry it wont upload the pdf. Please private message me and I will email it to you.

[Timcup]

Thanks, got the manual as well, just having difficulty getting the replacement vent. Where did you get yours?