One solution and one question (maybe two in one) >>>

[1911tex]

Solution: Went to the boat today for a quick sail; returned and found green antifreeze in the Bilge!! Lordy...here we go again. Checked the engine from front to back, side to side, hoses, clamps, etc. No leaks, no drips ! Noticed the original (I think its original..it was old, had a large very faded "35" written on the side) overflow plastic bottle was empty. Removed it and examined it closely....Photo #1 below illustrates an almost imperceptible open joint...I had to blow in it to verify!

Question: Second photo is the 11/16" (just in case you wanted to know) bolt/dipstick for my original Hurth 50 tranny. When measuring the amount of Dextron III non-synthetic tranny fluid (10oz correct?)....is the correct full level at the groove at the very bottom of the stick?, and is the measure taken with the bolt head sitting on top thread of the hole, or screwed all the way down, then unscrewed to check the fluid level? Reason I ask...I had engines that required measurement taken with dipstick sitting on top of the tube, then pushed home.

Interesting note: The dipstick is hollow with a hole at top, I guess to release fluid pressure inside tube. Why not a solid tube or stick?

Appreciate your kind assistance!

 

[Frank Langer]

I'm not sure, but on my former Hurth 50 transmission I think the manual said to screw the dip stick in when checking fluid level.
Also, if you have a diesel engine, one can buy diesel coolant, purple in colour, similar price, but formulated for diesel engines, better than the green stuff.
Frank

 

[David Grimm]

Advanced Auto typically has coolant overflow tanks in stock. I prefer the all plastic one. Transmission fluid is to the line threaded in.

 

[1911tex]

Is 10oz the correct amount of tranny fluid?

Just found this info (.44 quarts):

Sailboat Engine Parts and Boat Parts- TOAD Marine Supply

TOAD Marine Supply - offering a complete line of sailboat engine parts, hardware, boat parts and supplies for the boating enthusiasts. One source for all of your marine engine parts, sales and service.

shop.toadmarinesupply.com

Also just found this old thread on our forum (see Loren's post #6)...confusion here...11.8 oz. or 10 oz. Seems 11.8 is correct:

Fluid capacity for Hurth 50 Transmission

Two quick questions if i may? I've been trying to locate a definitive answer to the question of what is the recommended fluid capacity for the Hurth HBW-50 transmission, which is behind my Universal M-25 on an E32. I have seen .29 quarts, .44 quarts, and 1.3 pints. Does anyone know for sure...

ericsonyachts.org

 

[David Grimm]

There is a download for the full manual on this site somewhere.

 

[David Grimm]

*not threaded in! Better go check mine!

 

[1911tex]

O.K.: "WHEN CHECKING THE FLUID LEVEL....DIPSTICK SHOULD BE INSERTED ONLY...NOT SCREWED IN"......!!!
AND 1.3 PINTS...1 Qt Dextron III= 946ml or 32 oz. (2 pints = 1quart); therefore, 16oz=1pint

Now we have an answer, or do we...11.8oz or 16oz? Are we under filling our Hurth 50? Maybe that is a reason for problems?

OH, but that is not for the 5421 M25 engine...here we go again.....? But the same tranny??

I think I will just fill to the grooved mark with the dipstick inserted and not screwed in. Then lock it down. Getting dizzy.....

 

[David Grimm]

Type A fluid. That's not Dextron III?! Is it?

 

[1911tex]

Type A fluid. That's not Dextron III?! Is it?

Remember...that may be a 40-50 year old manual. I will stay with non-synthetic Dextron III, unless positively notified otherwise.

 

[Kenneth K]

Here's the page from the Hurth owners manual that shows fluid quantity and how to set the dipstick. It's on pg 13 of the attached manual.


Also, a pic from the Ericson manual about the Hurth. This manual has the wrong qty, but it does say that "Destron [sic] II" is a Type A compatible fluid.



Wikipedia says: Dexron-III(F) has the same low-temperature fluidity as Dexron-II(E), for better transmission performance in cold weather. ... This fluid is backward compatible with all previous Dexron fluids as well as the Type "A" Suffix "A", and the Type "A" fluids produced from 1949–1966. Plus, a whole lot of other interesting info like how earlier fluids use Sperm Whale oil as an anti-corrosive additive:

DEXRON - Wikipedia

en.wikipedia.org

 

[1911tex]

I will be putting the non-synthetic Dexron III (correct spelling!) in the tranny next weekend after pumping out the old until I hear the sucking sound of a straw at the end of a milkshake.

I have a full quart of the Dexron III stuff. Letting the bolt (11/16" or 17mm) threads rest on top of the hole while adding and re-checking to the full groove mark at the bottom of the stick, then locking it down.

I will note what is left of the quart and report back.

Too many theories and manuals all with different fluid quantities confuses my simple mind.

 

[1911tex]

I will be putting the non-synthetic Dexron III (correct spelling!) in the tranny next weekend after pumping out the old until I hear the sucking sound of a straw at the end of a milkshake.

I have a full quart of the Dexron III stuff. Letting the bolt (11/16" or 17mm) threads rest on top of the hole while adding and re-checking to the full groove mark at the bottom of the stick, then locking it down.

I will note what is left of the quart and report back.

Too many theories and manuals all with different fluid quantities confuses my simple mind.

Done: Checked tranny fluid first with dip stick (bolt) threaded all the way in. Fluid level was just below the stick full mark. Checked with bolt dip stick sitting on top of hole. Not a single trace of fluid OUCH !!! As mentioned...sucked the old stuff out with tube pushed as far as it could go...until the gurgling sound of a straw at the end of a milkshake. Obviously old fluid remained.

Thankfully, the bolt/dipstick is not in a bad location to get to on my boat (M25 (5421)); however the drain plug is a non-option. Put a small funnel in the hole, poured a little Dexron III at a time, checking the stick level with bolt sitting on top of threads each time. At stick level mark put in 9oz, not the 1 pint (16oz) the manual recommended. I have no idea how much old fluid remained...which is not relevant anyway as I sucked it out, not using the drain plug....just filled to the stick full mark as there must be old fluid remaining due to gurgling sound.

I plan on putting 6-7 hours on tranny then changing again, hopefully getting most of old fluid in the mix.

Bottom line according to the manual above...my tranny was definitely significantly low when stick bolt properly sitting on top of the hole. NOT A GOOD THING!!!

 

[Kenneth K]

I plan on putting 6-7 hours on tranny then changing again, hopefully getting most of old fluid in the mix.

Yeah, I'd probably do that too. I think I did that on my first fluid change. On subsequent changes
(every, or every other season) the fluid I removed looked pretty clean so I haven't bothered double-flushing it again.

 

[u079721]

First time I changed the oil in my tranny I sucked out all I could, and then just added fresh oil to the mark. But I had a heck of a time being able to actually see the oil level on the dipstick, as the new clean oil seemed to be almost invisible. Maybe there was something different about my dipstick, but I just couldn't see the oil on its surface. When cleaning off the dipstick before replacing it for yet another measurement I noticed that the stain left on the paper towel sheet was visible. After that I visualized the oil level by quickly laying the dipstick on a paper towel and rolling it across to see the stain left by the oil. So if anyone else has that problem I offer up this tip as a way to help visualize the oil on the dipstick.

 

[Kenneth K]

But I had a heck of a time being able to actually see the oil level on the dipstick, as the new clean oil seemed to be almost invisible. Maybe there was something different about my dipstick, but I just couldn't see the oil on its surface.

Funny, but I have the same problem every time. The dipstick itself is pretty "shiny" so it makes it hard to see the clean fluid. I've tried drying mine off with alcohol or acetone first, and even roughening up the surface a bit with a scratch pad first to help later determine the wet vs dry surface.

 

[Loren Beach]

When withdrawn for the viewing, lay it flat on a clean blue paper shop towel, and gently roll it over to the other side. Read the point where the oil presence ends on the towel.
(Old mechanics trick I learned in the 60's)
Still hard to read but better by far than trying to eye-ball the dipstick. That ATF oil/fluid is really really clear.

When measuring, Hurth sez to rest the dipstick shoulder on the top of the thread opening, and not screw it in, IIRC. (per reply #10 , this thread)