Oil for MD #9 Mower?

[Does’ Leap]

What do folks use for gear oil in their mowers? Lynn Miller calls for foam depressed 10 weight hoist oil. I have tried in various parts stores and tractor shops around here and everyone looks at me cross-eyed. He says not to use 90 wt gear oil. Any suggestions?

George

[Mark Cowdrey]

I use whatever blend I have in the shop for my modern truck/auto, e.g. 10w-40.
Mark

[Barw]

I use synthetic gear oil in the mower.

[J-L]

I just put the recommended 80 weight in mine. I may drain it out this year and try something lighter and see if there is really any difference. I’m not convinced you’ll see any difference, but I’ll give it a try first before I make up my mind.
By the way, nobody I’ve checked with has every heard of the 10 Wt Foam Depressed stuff Lynn Miller talks about either.

[near horse]

IMHO – the low speeds and durations that the gears are operating at only require (and I use that term loosely) some lubrication – nothing elaborate. Remember that those older units (MD 6’s and JD 1 & 2?) ran no oil baths at all although there were lube cups. So I think lighter weight stuff is just fine as long as your seals don’t let it leak past (replace the seals soon). No need for something expensive – like Mark, I’ll grab whatever is on the shelf.

[Big Horses]

I agree with you Geoff. They were designed to work with some pretty basic technology, and anything will most likely be an improvement. I doubt that foaming will be much of an issue.
John

[Jay]

Ditto all of the above about use what you have on hand and just use common sense/care. They are made to be used in real situations, and don’t need extra care, just regular attention. The seals are pretty easy to replace and readily available at the auto parts stores or from Macknair. If the bushing is worn, it can be replaced and is available, but it’s a little more of a job to get out and then get the new one in straight, but again well worth doing if it’s worn. I have just replaced 2 pitman shafts where they were worn along with the bushing to the point where there was too much slop- again shaft from Macknair. Jay

[near horse]

Sooo Jay, how do you get some of those worn bearings out? They often seem to almost fuse with the housing to where you can’t easily tell if you’re actually trying to drive the bearing out or not. I’ve thought about trying to split one but was afraid of really tearing things up. What’s your “secret”?

[Stone Horse Farm]

My manuals for the McD #7 and #9 both say to use SAE 20 wt motor oil, and specifically says DO NOT use heavy transmission oil.

As for replacing those pesky worn pitman bushings, D.A. Hochstetler & Sons in Topeka, Indiana 574-642-1144 has a simple tool to drive the bushing out/in without damage. I have carefully split the bushing using a hacksaw blade, too, in difficult cases.

[Donn Hewes]

I got a cool little tool for pulling those out, but I can’t say where I got it from! A piece of metal machined to fit right in the back of the bushing. Then a hole in the center for a threaded rod. Works perfect on the number nine where there is only one bushing. On the number seven you are trying to pull two at once and not quite as easy. For my next trick, and after careful consideration with Norm Macknair and others, I will attempt to place a new bushing in an egged out housing using JB weld (epoxy). I will let you know how it goes. Donn

I use plain motor oil. Be sure to clean the gear box out if it is full of gunk. Also don’t over fill, half of the lowest gear in the gear box is enough. I need to look in the automotive world for an easy solution to replace lost or wasted gaskets.

[mitchmaine]

about that gasket…………i took an oil bath last summer trying to get by without and couldn’t squeeze that cover down hard enough..so i desperation i plunked the cover down on a tractor inner tube and cut a not so pretty one out and i worked pretty well. it seems to have made it through the winter, and you could easily make a prettier one than my try. i tried to make mine a half inch bigger inside and out from the cover, with holes for the bolts that were cut first. but a nice clean factory cork would sure look sweet. good luck there, mitch

[Jay]

I use a puller like the one Donn describes- it is just under the diameter of the bushing and has a shoulder that fits inside the bushing, and a hole in the middle for threaded rod. The originals were split- it’s very hard to dig or chisel them out without damaging the housing. I will take them out and install your new one for $50 here at my shop. Takes about an hour and a half start to finish if no complications. Jay

[nihiljohn]

I found hydo jack oil at the Car Quest Auto parts store. No wt. is given, just “jack oil”. They had Car Quest brand and Gunk.

[near horse]

@Donn Hewes 34711 wrote:

I got a cool little tool for pulling those out, but I can’t say where I got it from! A piece of metal machined to fit right in the back of the bushing. Then a hole in the center for a threaded rod. Works perfect on the number nine where there is only one bushing. On the number seven you are trying to pull two at once and not quite as easy. For my next trick, and after careful consideration with Norm Macknair and others, I will attempt to place a new bushing in an egged out housing using JB weld (epoxy). I will let you know how it goes. Donn

I use plain motor oil. Be sure to clean the gear box out if it is full of gunk. Also don’t over fill, half of the lowest gear in the gear box is enough. I need to look in the automotive world for an easy solution to replace lost or wasted gaskets.

Donn – I thought you were the one who posted the Autozone equivalent seals for a #9. I even wrote down the part number somewhere here (not in the shop!). If that’s what your talking about I can sure look and find the number(s). Seems like I recall people using 2 instead of one due to the Autozone’s being a bit thinner.

I’ve got to see the tool for pulling one of those bearings (really more of a bushing as I recall).

The lower end of my mower can use a seal/bearing job – she’s an oil slinger like Mitch mentioned. Call her the “Thunderbolt Grease Slapper”.

[Author]

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