Hurth transmission overfilled

I'm in the middle of my first spring maintenance on a 1988 C34 with the Universal 25 (XP? I'm not sure). Replaced the engine oil and raw water pump impeller. Now it's on to the fuel filters, heat exchanger zinc, and the transmission fluid.

When I finally managed to get to the the transmission dipstick, I was shocked to see that the level is way too high: 2 full inches above the bottom of the stick. The manual says "don't overfill", but the PO did, and I ran that way for about 50hrs. I don't know how these things work, so could someone please explain whether I might be in trouble? What's wrong with too much fluid? My plan is to drain and refill to the correct level with Chevron MD-3 (that's what is in there now).

BTW, I find it curious that the boat manual and the engine manual don't say anything about the HX zinc, even though poking around on the internet has convinced me that it's important.

All advice appreciated.

I hope you meant E34 not C34. Curious, when I went to check on the fluid level on the transmission on my E34 (with the Universal 25XP), the only way I was able to remove the dipstick was to remove a bolt from the heat exchanger bracket and move it out of the way, very poor design. Did you have the same problem removing the dipstick?

BTW, the heat exchanger Zincs are easy to change, put your finger over the hole when you extract the old one and then insert the new one, loses only maybe a cup of water. The next time when you have the extra brass plug you can just change the zinc rod for very little money.

The subject of how much ATF is just right comes up from time to time.
http://www.ericsonyachts.org/infoex...acity-for-Hurth-50-Transmission&referrerid=28

http://www.ericsonyachts.org/infoex...03-Synthetic-Transmission-fluid&referrerid=28

And there are others with minimal searching.

And for some trivia about what might go wrong while you are changing that oil....
http://www.ericsonyachts.org/infoexchange/entry.php?263-Coolant-Leak-near-the-Heat-Exchanger

Cheers,
Loren

HerbertFriedman said:

I hope you meant E34 not C34. Curious, when I went to check on the fluid level on the transmission on my E34 (with the Universal 25XP), the only way I was able to remove the dipstick was to remove a bolt from the heat exchanger bracket and move it out of the way, very poor design. Did you have the same problem removing the dipstick?

BTW, the heat exchanger Zincs are easy to change, put your finger over the hole when you extract the old one and then insert the new one, loses only maybe a cup of water. The next time when you have the extra brass plug you can just change the zinc rod for very little money.

Click to expand...

My boat is an E34, but I slipped because I've been finding lots of good engine advice on Catalina forums (especially that Reality Check site).

I did have to push my HX aside. It's a replacement unit, made in Bellingham, WA. I'm going to call them tomorrow to get the specs on the zinc. I want to have a complete unit ready when I unscrew the plug.

Loren Beach said:

The subject of how much ATF is just right comes up from time to time.
http://www.ericsonyachts.org/infoex...acity-for-Hurth-50-Transmission&referrerid=28

http://www.ericsonyachts.org/infoex...03-Synthetic-Transmission-fluid&referrerid=28

And there are others with minimal searching.

And for some trivia about what might go wrong while you are changing that oil....
http://www.ericsonyachts.org/infoexchange/entry.php?263-Coolant-Leak-near-the-Heat-Exchanger

Cheers,
Loren

Click to expand...

Thanks, Loren. I did read those, and more. But I'd still like to know why it's wrong to overfill, and if there is anything I need to do. When I hold that dipstick up against the housing, it sure looks like whatever is in there doesn't need a lot of fluid.

Stefan,

My guess would be that Hurth/ZF had concern that the moving parts would whip the ATF into a froth and it would then become too low and loose the ability to lubricate those moving parts.

Personally, I would be more worried if it was too low.

Just observe for the dreaded slippage.

Universal 5411 Transmission Fluid Level

Hi Respected Sailors
We fill to the dipstick mark. Its worked for 35 years (knock on wood). This year I did not want to dig out my notes from the bottom of basement storage so I looked at the Universal 5411 manual on line. Grossly overfilled transmission. Went to basement and dug out my notes. Repumped out transmission refilled and all is well.
First year delivery transmission vented in bilge on RI to NH trip. Reduced the level to the dipstick mark and all was well. Keep your fingers crossed for us. Mooring neighbor good mechanic and his Hurth failed last year with 35 years on it (ugh) cost him two weeks on the hard.
Best Regards
Pat
1981 E28+ Universal 5411

And the dipstick is hard to read. A trick I learned here is to lay the wet stick on a paper towel--the trans fluid becomes immediately visible.

Christian Williams said:

And the dipstick is hard to read. A trick I learned here is to lay the wet stick on a paper towel--the trans fluid becomes immediately visible.

Click to expand...

Awwww you beat me to it - I was about to give the same trick. Until I learned that trick I could never tell if I had overfilled or not. The same trick is pretty useful on a car's power steering fluid too.

I know you can fill it up entirely to protect during long periods of storage (read that in the manual) but cannot run this way. The fluid expands when heated and it won't have anywhere to expand to, and blow the seals. If you did run it overfilled and it's not leaking, I would just fill it appropriately going forward and not worry about it.