What bulk oil for mobile equipment should we be filtering and to what iso contaimination level should we be holding the bulk oil at. We have a standard for slow speed journal bearings and hydraulics. What about transmissions (auto. and manual) and differentials. Trying to establish which bulk oils to filter and to what level.

Sherman,

On your hydraulics I would filter the oil to 10 micron absolute unless you are have servo or proportional controls and then you may have to go to 1 micron. Be careful of dirty filter indicators on any portable filter units because they go into bypass before they indicate anything. I would recommend if you use a portable filter unit add pressure differential gauges on it. As far as filtering the lubricating oil for your bearings I would go to the manufacturer of the bearings and ask them what the micron rating should be of the lubricant based on the application. Your oil supplier should be able to tell you how clean they filter (or strain) the oil when it is put into bulk storage. You can compare the data and make a better decision. I hope this helped a little.

For mobile equipment we target -/16/13 according to ISO4406 for fill oil (ie coming out of the nozzle in the shop). I am not a filtration guru by any stretch, so how you get to this level is a question for the experts.

We have found however, that even if your lube supplier guarantees they put it in your tank at -/16/13, it doesn't mean it will be that level by the time it gets to the nozzle, especially if you have significant pipe runs from the bulk tanks. You might find you need some more filtration near the nozzles to reach your target.

We use this target for fill oil for the following compartments:
Hydraulic
Transmission
Final Drive

Good Luck,
Matt McLeod.

We do not assume any of the oils we recieve from our supplier is clean enough to use upon delievery. As a matter of fact we try to pull oil samples of the bulk oil when it is delievered to verify what we are getting is reasonably clean. We have had bulk oil delievered before that has been highly contaminated with water and would not accept the product. We expect reasonably clean oils from our supplier and we assume the responsibility of polishing it ourselves. That is the only way we can guarantee what we are putting in our assets.