Hydraulic System Repair

Hitachi ZW40 Axle Oil Leak: On-Site Repair

before

This is the front propeller shaft.
You can see the oil leak at a glance.

after

（アフター）日立　ZW40（ホイールローダー）　アクスルオイル漏れ出張修理油漏れ修理完了後のプロペラシャフトです

We replaced the seal and removed the oil and dirt, and it is clean again.
We will say it again: repair oil leaks right away.

Background

“Oil is leaking from under our wheel loader…”

Hello, this is Saijuki Engineering.

Today we show an on-site repair of an axle oil leak on a Hitachi ZW40 wheel loader.

Axle oil is a type of gear oil that protects and lubricates the gears and bearings inside the drive axle.

In other words, if the lubricating oil runs out, the bearings and other parts can seize from friction, and the repair after that becomes much harder and more expensive.

Let’s get started with the repair.

[Repair Details]

An oil leak from under the machine that is easy to miss

First, we went to the site to find where the oil was leaking from.

We found oil leaking from the connections of both the front and rear propeller shafts.

Repair procedure

Drain the axle oil.
Remove the propeller shaft.
Expose the inside of the propeller shaft. We found that the cause was a deteriorated seal.
Clean off the oil and dirt, remove the old oil seal and press in a new one.
Reinstall the propeller shaft and refill the axle oil.
Check operation and the job is done.

The front and rear axles have separate axle oil, so we carried out the work above on both.

We then ran the machine for about 20 minutes. There were no problems, so the job was complete.

[For Those with Similar Concerns]

Repair oil leaks immediately. That is the one thing to remember.

As we always say, an oil leak must be repaired immediately, no exceptions.

Especially for machines like this wheel loader that may be driven on public roads, always carry out a pre-start inspection.

If the machine stops in the middle of the road, it can cause trouble for other traffic.

Leaving an oil leak unrepaired is very likely to lead to even more expensive repairs, so saving money here is not a smart choice.

So if you find an oil leak, please have it repaired as soon as possible.

More hydraulic system repair cases (Japanese)

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Repair Details

We removed the propeller shaft flange (the ring-shaped rim fitted to the end of a shaft or pipe).
We could see the oil seal that caused this leak, but it was so covered in grease that the seal itself was hard to see.
We replaced the oil seal, then cleaned and polished the parts until they were shiny.
This is the propeller shaft flange. It was also covered in oil and dirt.
Of course we cleaned it as well before assembling it back onto the propeller shaft.