Wheel bearings

[daterplant]

Is there a recommended change out hours/klms for wheel bearings on off road trucks/loaders eg. komatsu HD465-7,WA500,WA480 Cat 769C/D, 980G/H,
Thanks to anyone with info.

 

[Nige]

I assume you mean front wheels, the rears would get done when the final drive is overhauled. We always do front wheels at the same hours we do our final drives. That size of truck using good oil (FDAO-spec SAE 60) and an oil analysis programme plus kidney-looping final drive oil every 500 hours or so I'd be thinking 15,000+ hours. Typically we do ours at 20k, but that's on much bigger trucks.

 

[daterplant]

Thanks nige
On the oil filled hubs the oil analysis would show wear rates. However on the komatsu machines or others which use grease filled hubs I can't find any information regarding service intervals or bearing inspections for the hubs, I would estimate an inspection every 6000hrs for grease filled hubs, what do you think?
What is kidney-looping of final drive oil?

 

[Nige]

Kidney-looping aka dialysis. On the rear axle the suction side of a pump and a fine filter is connected to the diff drain plug. The return line is connected to the fill/level plug of one of the final drives. When your machine is on a 500-hour PM you hook up the dialysis equipment and leave it pumping during the whole time the PM is going on. Usuaully it gets used in conjunction with a particle counter so that you can measure the cleanliness of the oil before and after the process. The process can also be used in wheel loader axles, hydraulic systems, transmissions, everything except engines basically.

Here is an example although I'll say now I have never used this particular brand of cart, it's just what Google turned up. http://www.normanfilters.com/filtra...idsubmission&gclid=CMGY07-PprACFUOo4AodISNTYQ

Be careful with oil analysis in oil-filled hubs. The oil gets changed so often (every 500 hours) that it can be extremely difficult to pick up trends caused by bearings wearing. I'll be honest and say that on front wheels I have found that if the bearings are correctly adjusted from the get-go they usually don't give much trouble.

Using dialysis we run the oil in our truck rear axles (FDAO SAE 60, nobody in their right mind uses 50 any more) for 10,000 hours between changes. So basically we only have one oil change between new components and pulling them out at end of life.

Can't offer any ideas on grease-filled hubs to be honest. I have never worked on anything that big that didn't use oil as a lubricant in the front wheels.

 

[daterplant]

Thanks Nige

What do the oil companies and dealerships think of 10,000 hours between changes.
I like the idea of 10,000 hours on oil, it would save a lot of $$.

 

[Nige]

We do our oil life extension programme hand-in-hand with the oil suppliers. They have no issue with it so long as the lubricating probperties of the oil are maintained throughout its life. Generally the reason you change an oil is to remove the contamination that is suspended in the oil produced by normal, or abnormal in some cases, wear. If you are doing an efficient dialysis then you are removing that contamination. Ergo the oil can run waaaaaay longer. Take our haul trucks for example. The rear axle takes about 200 gallons or oil. Change period is recommended at 2000 hours. So I'm saving 4 changes or 800 gallons of oil per truck every 10,000 hours (approximately 18 months) that they run. Multiply that by 30 trucks and you have 24,000 gallons every 18 months or about say 16,000 gallons a year. Subtract the cost of a dialysis unit at around $5000 plus the filter changes in the unit, and a bit of air or electrical power to run it and you still have major savings.