Should there be a breather fitting next to the dipstick? Mine has a pipe plug. See picture. Only breathing the V drive sump has right now is through the dipstick tube... which doesn't seem right.
The dipstick is not a breather cap. The breather cap in the attached photo is the round button on top of a square 90 degree elbow on the right side mid-face surface of the v-drive. The dipstick in the photo is the round knob on the upper right side of the v-drive. I do remove the breather cap when changing or checking the fluids of the v-drive, all of which is done through the dipstick.
Problem was, and the reason for the question, was that after running for several hours and checking the v-drive oil level the next day, the oil level on the dipstick level showed at the very bottom of the stick. No signs of oil loss through the shaft seal or anywhere else. Turns out what was happening was that when the oil and air cooled in the drive gear box it created a vacuum and pulled the level in the dipstick tube low thereby giving a false low reading. Where the breather should be is a non-vented pipe plug. Only venting left for the drive is through the dipstick tube. Likely the drive was shipped from Walter with the pipe plug which was to be replaced with a vent fitting by the installer... which was not done. Will replace the plug with a breather. Another mystery solved. Cheers!
You are describing a quirk of the v-drive dipstick. The dipstick may show a low level when first removed, but will show a normal level on another insertion and removal, even when there is a breather cap. I do not know the mechanism for this quirk, but there seems to be no mechanical failure, so all is well.
I can see you'd get that "double-dipsticking" requirement if the breather was plugged up but other than that this makes no sense. Have left a message with Walter along with the picture. Will see what they have to say about it. Have gone through the drill of over-filling the drive a couple of time because of the faulty reading.
Totally unrelated question: Have a Hurth transmission with an oil cooler. Is there a zinc in the cooler?
Cheers!
Yep, that plug was left in from shipping. Walter sending me a breather.
"You are describing a quirk of the v-drive dipstick. The dipstick may show a low level when first removed, but will show a normal level on another insertion and removal, even when there is a breather cap. I do not know the mechanism for this quirk, but there seems to be no mechanical failure, so all is well."
This was also true on our boat. I never figured it out, but fer sure I had to "double dip" the stick to read accurate level.
That leads to the question of how many over-filled Walter drives are out there with owners wondering why the output shaft seal is weeping oil.
The v-drive should not remain over-filled if one adds fluid then properly checks the new fill level.
So noted. Will check to be sure level is correct. Cheers!
Ah, the mysteries of life are grand.....the magic dipstick story :)