YANMAR VIO 40 excavator has bad oil leak on the track drive motor.
Closer inspection revealed that the seal between the drive hub and the mounting flange had given way. 

A new seal kit was located complete with all the o rings and the large steel compression seals.

We start stripping the drive unit and remove the old worn compression seal with it's steel slip ring.

Notice the steel slip ring and the rubber o ring that seals and provides the constant pressure on the seal.

The new slip ring is at the bottom, the old one is on the top one.
Can you spot the contamination wear marks on the old slip ring?
Notice the machine ground finish to the new component.

The contamination between the drive unit and the drive hub slowly wears away the sealing face on the slip seal.
This drive hub was filled with hydraulic oil though, a sure sign that the motor drive seal had popped.
This caused the hydraulic oil to leak into the drive unit and pressurise it.
The leak seen below was most probably caused by over pressure.

in the bottom left corner is the drive motor seal that caused the leak into the drive unit.
Made from special nitrate this seal is best replaced with the genuine item, the after market parts do not last!

A view of the planetary gears inside the hub assembly.

All assembled and bench tested, the tracks replaced and away we go.
This repair requires a fair amount for technical skill, mostly a generous portion of patience , fitting the slip seal.

Enquiries regarding this type of repair are welcome.

Call or text Charlie on 0403 861 597

You are also welcome to contact us on the form below.