Water hosing ruins bearings ?

[WilliamTO-35]

My circa 1985 Deutz Allis 912 Hydro lawn tractor has been a great machine. It has the Kohler 14 hp. K321 cast iron engine, and a 42 inch mower deck. It's heavy duty throughout . One recurring problem I had, however, was premature failure of the quill assembly ball bearings. Being a three blade deck, it has three quill assemblies. Each quill consists of a shaft, two bearings plus metal shields, the housing, a V belt pulley on top, and a mounting for a blade on the bottom.
I used to have to replace one or two bearings ( out of a total of six) every season. I asked my parts dealer about the issue, and he asked me if I used the garden hose to clean the grass clippings off of the top of the mower deck. I did in fact hose down the deck frequently. He said he had seen a correlation between using water to hose off the deck and premature bearing failure. He suggested just using compressed air to blow out the clippings. Since I started taking his advice, I haven't had a bearing go bad in the last 5 seasons. Has anyone else had experience with this issue?

 

[SPYDERLK]

Do those quills have grease fittings to qrease the bearings?
larry

 

[vwnotrunning]

Water will cool the bearings causing them to suck in moisture causing the premature failure. Alway let bearing and seals cool before spraying with water.

 

[WilliamTO-35]

As for the question about grease fittings, the answer is " sort of ". Only the lower bearing nearest the blade had any provision for getting grease. As best as I can recall, the grease fitting is not actually on the quill housing, but on a sheet metal cone that fit between the blade and the bottom of the mower deck. The cone volume was huge, and would take at least two tubes of grease to fill. Plus, there was no effective seal to keep the grease from leaking out toward the blade, plus the sheet metal cone itself was prone to rusting out from the outside. It's a very odd provision for greasing , and looks like an afterthought at best. Since the upper bearings went bad as well as the lower bearings, I never thought the greasing provision had any effect.
The last time I replaced any bearings, 5 seasons ago, I did not fill that cone with grease, but I left plenty of grease inside the housing between the two bearings. And, as suggested above, it's quite possible that hosing off the mower deck while the quills were still warm did contribute to water getting sucked into the bearings. I didn't always hose it off when it was warm, however, and I also wonder if water sitting on top of the bearing under the pulleys would seep into the bearings. The bearings have some sort of polymer seal shielding, but may have gotten damaged .

 

[richamor]

Precisely the reason I quit using the water hose and started using the leaf blower. I still wash it off occasionally, but not after using it.

 

[jda1961]

that happened to my craftsman 50 inch deck, had to replace bearings after a couple years. inside the mandrels are an air space between the upper and lower bearings, every time i washed the deck, water would get in there, screwed up the lower bearings. when i replaced all the bearings i drilled a hole in the mandrel housings and put a grease fitting on each, pumped it full of grease. its been 8 or 9 years since i did that, no more problems.

 

[Wacky]

Water will cool the bearings causing them to suck in moisture causing the premature failure. Alway let bearing and seals cool before spraying with water.

Good info:thumbsup:!

 

[smstonypoint]

He said he had seen a correlation between using water to hose off the deck and premature bearing failure. He suggested just using compressed air to blow out the clippings.

That's exactly what the dealer advised when I bought my last mower.

Steve

 

[2006RonB]

My dealer suggested running the deck for a few minutes after washing out. Flings water out, drys bearings off. Seemed to help.