Oil drop in gearbox

[Pascal]

Hi guys,

Ever since the repair I did on my gearbox of my SuperMajor http://www.fordsontractorpages.nl/phpbb ... al+gearbox
oil from the gearbox was slowly leaking into the rear axle.
Once in a while I pumped some oil back from the rear axle to the gearbox via the hydraulics of the tractor.

About two weeks ago I went to a festival and before I went, I pumped some oil from the rear axle to the gearbox. Afterwards I noticed I pumped a bit too much
and the oil was above the maximum.
The weather was really hot over here: about 30 degrees Celsius (86 degrees Fahrenheit).
During the day I checked to oil level in the gearbox, and unfortunately the oil dropped far too much! I had to pump at least 4 litres to get the oil level correct again.

Perhaps a combination of too much oil in the gearbox and hot day?

What could be the reason of the oil drop?
During the repair on the gearbox I also replaced the rubber seals inside the pto-gearbox. My guess is, that I didn't mount these correctly, since it was
quite a struggle for me with the two seals?



Or is there another place where the oil can leak from the gearbox to the rear axle?
Looking forward to see you reactions!

[Aussie Frank]

Hi Pascal,

There is a second seal on the output shaft of the gearbox. The only way to get to this seal is by splitting the gearbox from the back end. This is a big job so you might want to drain all the oil and pull the PTO box out just to make sure the PTO seal is not the problem. If the seal is OK all you have lost is the PTO unit gaskets and a little bit of time. If you are right and the PTO seals have failed because you didn't manage to get them in right at least you won't have to split the tractor.

Regards, Frank.

[liam]

The seal part number is E27N-7082-A

[super6954]

Hi Pascal
If you think its the bottom seal drain all the oil from the gearbox only. Put the plug back in and leave it sit a day or so. go back and take the plug out and see if you get a large quantity of oil out like a litre plus. if you do the back axle oil is running through the pto drive box seals indicating gearbox oil with head pressure will go the other way . if you get a few drops and no more its looking like the axle input shaft seal at the top is gone
Thats how I test them to get an idea whats wrong without taking anything apart.
I have had the odd one where both seals had gone when i fixed the bottom and filled the gearbox and tested the other way with the axle empty and gear box full though
Regards Robert

[AdrianNPMajor]

If the two seals haven't been replaced since your tractor was built, there's an argument for doing them so that you know where you stand. Splitting the tractor between gearbox and rear axle, once you have the necessary supports in place, is easier than you might think and once the two sections are apart, the upper seal can be accessed very quickly. Once done, you'll never have to worry about it again.

Oil leaking from the gearbox left unchecked puts the upper rearmost bearing at risk. This had failed on my NP Super when I bought it, making the tractor unuseable. I would advise taking action.

Regards

Adrian

[Pascal]

Hi guys,
Thank you so much for your advices!

Robert,
I followed your advice and drained the gearbox. After three days I found out, that about 300 ml of oil came from the rear axle to the
gearbox. That's quiite more than a few drops but much less than the litre you mentioned...

Since I had some time this weekend I removed the PTO gearbox.





When I checked the outer seal it actually looked better than I hoped.
What do you think: is it worth removing the seal for further inspection? Or does it looks likes the upper seal needs to be replaced?



From tomorrow my wife, my daughter and myself will enjoy a holiday on the isle of Menorca (Spain).
I am looking forward to read your reactions afterwards.

[AdrianNPMajor]

Hi Pascal

This does not look like the original seal - someone has replaced it. It doesn't look as if it's located properly. It should also be a double lip seal, given that it's job is to stop the gearbox oil going one way and the rear transmission oil going the other.

Hope you have a lovely holiday.

Adrian

[Kiwi Kev]

Pascal
There are 2x seals inside this part, and to replace them you need to removed most of whats inside.
The original seal was a double lip, but you may only be able to get a single lip, so may have to put in 2x singles back to back. The seal in picture looks like a single lip, so I presume you have already replaced these recently. Did you instal 2x.
Kiwi Kev

[henk]

Pascal,

Now to are at the point that the box is out, I would renew the seal and use the double lipped one.
You have to use special tools to avoid damage to the seal when placing it.