Flushing gear box with "machine oil"

[sundogfarmer]

I just replaced the tine shaft seals on a Baltimatic 180 cm rotovator and am getting ready to refill the gear box. The instruction manual (which was clearly not originally written in English) says to put some "machine oil" in the gear box, turn the shaft a few times, drain, then fill with new gear box oil.

So what do you think they mean by "machine oil"? What do other people use for this purpose?

While I'm at it, what do folks use in a tiller gear box like this? If the manual isn't specific I generally default to 80W-90 for gear boxes because I've got a lot of it around, but I'm sure there are other opinions out there.

Thanks!

 

[ptsg]

Just pour 80W-90 straight into it.

Rotovators are not that sensitive to oils as long as there is something in it.

Quite often, oil only gets changed when it gets contaminated by water or the seals go bad.

 

[LouNY]

If I'm going to flush out a gearbox or something similar I will use different things,
either just #2 diesel, or #2 with a slug of oil, or the same product that I'm going to run in it.
Just finished a rebuild on a front planetary hub, used the same gear lube to flush as it's going to be running 75-140 synthetic gear lube.

 

[TractorGuy]

Automatic Transmission Fluid makes a good high detergent flush oil.

 

[RalphVa]

I'd say ATF would be closest to machine oil. Don't think it has much detergent in it.

Any good GL5 oil would do for fill. Can't get excited whether dino or synthetic.

Ralph

 

[TractorGuy]

I'd say ATF would be closest to machine oil. Don't think it has much detergent in it.

Any good GL5 oil would do for fill. Can't get excited whether dino or synthetic.

Ralph

From Wikipedia:

Modern ATF consists of a base oil plus an additive package containing a wide variety of chemical compounds intended to provide the required properties of a particular ATF specification. Most ATFs contain some combination of additives that improve lubricating qualities,[2][3][4] such as anti-wear additives, rust and corrosion inhibitors, detergents, dispersants and surfactants (which protect and clean metal surfaces);

 

[Sawyer Rob]

You can just flush it with diesel fuel, no problem at all...

SR

 

[CalG]

UTTO!

tractor oil

 

[RalphVa]

You can just flush it with diesel fuel, no problem at all...

SR

Good suggestion and probably the cheapest.

Ralph

 

[oosik]

After doing nothing to the gear box on my Troy Bilt Horse for five years. I used diesel fuel to flush. Seemed to work just fine.

 

[Gale Hawkins]

Diesel is a good option in most cases but I find the old 303 UTF for around $20 for 5 gallons on sale which cost wise is not that much more. Under no load I will actually run the gear box a bit then drain. If some gets trapped and does not drain completely it is still lube oil and not diesel. A lot of old gear boxes do not have a low point drain on our stuff so I have to suck it have to suck it back out or turn it upside down.

How ever often I will do the diesel flush before the 303 flush. If the fill plug is large enough I like to use the diesel in a hand pump pressure sprayer on solid steam for flushing action. I know shops just kind of drain and refill often.

 

[def38]

My 231 had sludge in the gearcase. Drained the oil and ran some diesel in the gearcase while driving around the ranch with no load. Drained the diesel and filled with fresh oil and a new filter. The hydraulics now operate much better and faster and the dipstick shows clean, clear oil. No leaks.