The engine is stripped down to the bare block where key measurements are taken to determine if repair or boring and honing is required. Once the required work is done, a bench test on a dynamometer is completed.
Mack Plovie
Most components are rebuilt in-house
While there are many components on a D11 track type tractor, key components rebuilt in-house by Finning include engine and drivetrain, hydraulic cylinders, operator cabs, and undercarriage.
Hydraulic cylinders, like the hoist and tilt cylinders for the blade and the ripper cylinders, are rebuilt in Finning’s cylinder bays. This includes full reseal of cylinders, honing out cylinder barrels, rebushing the ears, and inspecting the cylinder rod chrome for damage. Associated hydraulic hoses can also be built in-house or replaced with new.
There are very few components that Finning doesn’t rebuild in-house. An exception is cylinder rod re-chroming and hydraulic pumps, which are completed by outside vendors.
With respect to the diesel engine, the C32 is stripped down to the bare block where key measurements are taken on cylinder heads, crank and cam bores, and each cylinder bore to determine if repair or boring and honing is required. For instance, if the cylinder deck height is out of tolerance and too low, spray welding builds up the cylinder head deck and a machine called the “Rottler,” accurate to 1/10th of 1,000 of an inch, machines the cylinder deck back to OEM specifications. Once machining on the block is complete, cylinder liner kits are replaced alongside bearings, wiring harness, and more to fully reassemble the engine.
Before the engine can go back into the dozer, a bench test on a dynamometer is completed. The dynamometer uses fluid friction to simulate load on the engine. The force required to overcome this fluid friction is then measured to read engine horsepower, torque, and overall performance which is documented and compared to OEM specifications. Other driveline components, such as transmissions and torque converters, also undergo bench testing after the rebuild to ensure they meet OEM specifications before reassembly on the tractor.
One of the most important components on track type tractors is the undercarriage. With exception of the track group, comprised of rails and track pads, which is replaced with a brand-new track group, Finning rebuilds undercarriages in-house. The track frame as well as major and minor bogies are inspected for cracks and defects and are repaired as necessary.
Rolling stock, such as bottom or top carrier rollers, are replaced with new, while large items like front and rear idlers are rebuilt. The idler is first placed on a lathe to bring the worn, uneven surfaces true, then placed on an idler rebuild machine which uses two flux-cored arc welders to build up new metal on the surfaces where the undercarriage rails ride and wear. The process involves special pre-heating and cooling where the idler is placed in an insulated box to control the rate of cooling to properly cure the metal.
At any given time, Finning can have multiple D11s in the shop for rebuild, all at different stages. But, with all these components being rebuilt in-house, how does Finning have all the parts ready for comprehensive rebuilds?
Finning’s warehouse team builds parts lists for each rebuild using a 30-180 parts stocking outlook and strategy. To organize parts for each rebuild, a colour coding system is used to separate parts for each dozer, which is further broken down into segments to group parts in individual boxes. Each D11 rebuild has 177 segments which translates into a lot of parts and boxes, hence why robust parts stocking and organization is key to ensure parts are readily available no matter what phase or segment each D11 rebuild is in on the shop floor.
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