Water in the Diffs and T-Box

I caught a lucky break today when I took the Defender to a local auto service place to have the engine oil and oil filter changed. We’ve driven almost 12,000 miles on the trip, so it was time for another oil change. After the mechanic completed the oil change, he went on to check the fluid in the front differential and found water mixed with the fluid. He then went on to check the rear diff, the gearbox and the transfer box. Both diffs and the transfer box had water in the fluid, which was very obvious when they were drained.

Almaty mechanic changing the fluids
Almaty mechanic changing the fluids

I had intended to get the engine oil changed in Ulan Baatar when all of the other fluids were changed. The only reason it didn’t get changed there is that neither 10W40 or 15W40 oil was available. Had the oil been changed in UB, I wouldn’t have had it done here in Almaty. The water wouldn’t have been discovered and significant damage could have occurred.

The water obviously got into the diffs and transfer box during the regular wading the Defender had to do in Mongolia. We’ve done quite a few miles since Mongolia, so I’m relieved that there’s no apparent damage to the diffs or transfer box.

As usual, I had to convince the mechanic to use EP90 in the diffs and T-box. He wanted to use something else, but fortunately I had 6 litres of EP90 onboard.

With the fluids changed, I then took the Defender to a car-wash where she got spruced up a bit. She’s been covered in mud and dust for weeks so it was time to get it off.

Clean as a whistle again
Clean as a whistle again

When I got back to the hotel, Fed-Ex had delivered my replacement Terrafirma heavy duty drive flange that was shipped by John Craddock Limited. I had to go to the Almaty Fed-Ex office yesterday to complete a customs form and pay a fee. Once that was done, it was cleared for delivery the following day. A big thanks to John Craddock Limited for working with me to get the part dispatched to Kazakhstan so speedily!

Terrafirm heavy duty drive flange, delivered by Fed-Ex
Terrafirma heavy duty drive flange, delivered by Fed-Ex

The only part that I was missing is the screw-on cap (on the right in the photo above), but they don’t seem to be sold as a separate item, so I had to buy the entire flange. At least I now have a spare flange to add to my collection of spare parts. The zip-tied plastic bag had managed to keep the end of the drive shaft clean, but it was nice to be able to refit the correct cap (and to ensure it was tightly fitted this time).

Replacement cap securely fitted
Replacement cap securely fitted

The Defender is now ready for the next leg of the journey.



  1. Bit concerning Craig. Did have a similar issue with my front diff which was a holed breather pipe. Odd it should be in all three units though? Have a good look at the breathers for integrity.
    All the best

  2. Craig, I have totally enjoyed following your journey thus far. I will be reminding Darrin and the others to check it out. It truly is like reading a book.

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