PHD gearbox leaking oil

[TNhobbyfarmer]

Out of the auger shaft area. How difficult is it to replace the seal?

 

[Fallon]

Even easier to just fill it up with grese instead of replacing seals. Lubes almost as well as oil an eats insignificantly more HP. Might be worth it to replace the seal if it's a really nice high end PHD, but otherwise grease will cover up the problem & not cause you any problem. I've done that with the gearbox on my old Ford 917 flail. New seals would have been $70... I paid $100 for the whole mower & have maybe $500 total into it, so new seals just weren't worth it. The rest of the flail is going to wear out far sooner than the gearbox, even if I cut the gearbox life in half with grease over oil.

 

[Texasmark]

First thing is to check your fill plug. Is it just a regular NPT pipe plug or does it have a little rattle cap on the top....aka vent? If not, go to the auto parts store and get one with the vent.

Next, as Fallon said, change fluids. To each his own, but I use Lubriplate #109 available at most every auto parts store. It's primary use is engine rebuilding but it makes a super lube for gearboxes with a leaking seal as it's consistency is between #2 and 140 gear oil. Spreads out well in the box but resists leaking out of the seal.

Opinion: You really don't want to go through a seal replacement especially with a mower with any age to it. You can add a lot of grease (using the right fill plug) with little effort and solve your problem.

 

[jenkinsph]

How bad is the leak and how much do you need to use the phd? If minor leak and usage I would top it off before use. If you need to use it a lot or it leaks too much change to grease or other lubricant as mentioned above.