Hi.
I want to know the ideal time for overhauling an engine or a transmission for earthmoving equipments like Caterpillar or Komatsu. This should be a preventive overhaul time, before failure to come.

Thanks and regard,
Catalin

Catalin,

Could you please more specific about the equipment? maker, model, year, hours of work, etc.

Cata2200
Trying to predict an optimal time for conducting preventive overhauls on capital equipment and is highly dependant upon the environment and service factors the equipment works in. A much better approach is to let the equipment tell you when it is ready to be overhauled. Trending data collected from oil, coolant and hydraulic fluid analysis along with operating parameters over time will let you know when efficiency is lost due to excess wear. Trying to choose an "ideal" point based upon average life cycles may seem reasonable but often increases costs by both fixing things too soon and missing the mark and suffering unexpected downtime. A condition based maintenance strategy combined with proactive maintenance practices with the goal of maximizing operating life is usually a better choice.

I agree with BuckHntr's comment. The preventive overhaul time is somewhat an imprecise concept. Preventive maintenancec, togethher with proactive maintenance, belongs to Condition-based maintenance, and can therefore be implemmented based on the real conditions or healthy status of the macchinery and/or the fluids (oils,coolants or hydraulics). Designating a fixed time for overhaul brings us back to reactive maintenance, whihch is oftentimes supplied by OEMs.It can be good guideline but it is not what the end-users can invariably rely on.

Hello,
Great question and great posts..
Just like to add that both of the manufactures have recommended rebuild /overhaul hours charts. These are partially developed based on the average life of these machines, so if you were in the control group and were under-maintaining your equipment this would negetively affect the average, conversly if you were proactivly maintaining your equipment then you were positively affecting the average. Now consider your operation where do you fit? Ask the OEM what components are known to fail and are replaced during the overhaul and apply some additional condition monitoring on these components. You should be able to extend (with minimal risk) the "recommended" overhaul up to the point where the onset of a failure shows itself. You will then have the necessary time to respond to it, in a planned and scheduled manner.

regards.....

Hi Cata2200,

Alot here depends on what environment in which the equipment is working.

When I was working in the Mines, we did our overhauls based on both hours and oil analysis at that time provided by Cat.

We sampled all engines, differentials, gearboxes, final drives, and hydraulic systems at the prescribed hours. We relied on the results of the oil analysis and working hours on the equipment to decide when to overhaul.

Again in this situation, when an overhaul was required we would get the respective Agent to do the overhaul, expensive you might say, but in the long run no. We always got a 5000 hour warranty on the overhauls.

You need to work out what is best for your environment, there is no hard and fast rule.

Regards,

Kevin