My oil leak discussed previously, is not cured! The first time it leaked I thought I heard a noise as I braked for a corner and put it down to something under the back seat sliding forward under braking. The second time I thought I might be imagining the noise. Today I deffinatly heard a noise just like a dry wheel bearing being spun in the hand, I immediately stopped to see frothy oil running out of the breather pipe. This has got me really ‘foxed’. This axle has done 18000 plus miles with no previous problems with leaks. Inspection has shown all is well inside. The only theory I can put forward is that the oil level eventually dropped to the half pint level (that’s what I drained out to change the oil after the first leak) I only put a half pint back in on refilling. Now could it be that the oil is spinning in unison with the crown wheel because of the low level? instead of dipping into a ‘pool’ in the bottom of the axle case at each revolution. It must be under a lot of pressure to come out with a whoosh that can be heard inside of a chummy with the hood up! How can such a pressure even build up anyway. The breather is pointing up with a two-inch extension pipe. If it was pointing downwards as it should be it would be even worse. I will drain out and put the specified 7/8 pint in and see what happens. The breather has been removed and cleaned. Over to you

Hi Ian,

How much did you take apart to look inside???

Is the axle getting hot??

If you put a cork in the breather does it pop out?? (only joking)

Far more fun than a crossword puzzle anyday!

Regards

Rob

Ian, it does make you wonder how hot it's getting.

Regrads, Stuart

It does sound like you are boiling the oil, I would make sure and have another good check over the axle before you risk any damage.

Phil

I haven’t considered that it may be overheating, I had only done 3 miles today when it leaked so think this is unlikely. If it got hot enough to boil the oil in 3 miles I would think that you would have unusual noises when running. I will give it a go in the morning before changing the oil again and see if it gets hotter than usual. Thanks guys, keep your thinking caps on! Will report on progress. BTW is a 29 axle so can have a good look inside without to much trouble.

What about excessive bearing pre-load (for whatever reason)? This might produce heat, but not necessarily noise. Try jacking up & turning each wheel individually & also the drive-shaft by hand - feeling for any drag.

Interesting one Ian!

Cheers,
DG

Had a half hour run today, on return found oil running out of the breather again. The axle case and hubs were cool. Took of the inspection plate from the case to find it was full of oil foam. Drained it into a plastic milk container and found the whole lot was foam, with ‘no’ actual oil. When I drained out the original oil a couple of days ago the foam was only about ¾” on the top of the oil. The foam didn’t turn back to oil for over an hour. Had a thorough inspection of everything, wheels of the ground and all free (no oil in the drums) correct backlash on the CWP with no movement side to side, teeth all look fine and all bolts locked.
Phoned Castrol oil technical department for advice, after telling him the oil had been in the axle for about 25 years, he fell about laughing, when I said I had changed the oil for new from the same old tin, again much mirth.
The long and short of it is that oil has an antifoam agent, and goes through a test during manufacture to se how long the foam takes to disperse, this it has to do in a specific time, more agent being added until the time is achieved. His theory is that over time the antifoam properties deteriorate and foaming is the result. The foam is made up of millions of bubbles, making a pressure inside the axle case, hence the need for a breather pipe. He suggested Castrol D140 should do the trick, so that’s the next step. Quite surprising that the ‘new’ old oil in the tin foamed much more than the oil that had been in the axle itself.

Ian

I've got to laugh, have a look at the first reply on the original thread!!

Well done on not using a whole can of back axle oil in 25 years!!

Regards

Rob

see I am not that mad////

Well Rob,It was a gallon can of 140 and I only have a pint or two left, so that would work out to a half pint oil change every two years mind you if it was coming out at the rate it is now I would use it in a week!!!! glad to have made you smile.Well done Haydon,you were on the money.

Hi Ian - glad you've sorted it out. It's quicker to chaeck with you rather than Castrol but is D 140 definitely a non-detergent oil? If not, you'll have other problems in the future, be assured. Cheers, Bill

Hello Bill, That’s a question I didn’t ask, however this oil is part of the ‘Castrol Classic Oils’ range and said to be produced specifically for our needs. Our well-known A7 parts suppliers stock it. I will ask the question on Monday and get back to the forum.

Ian what about the Morris of Shrewsbury 140 oil it is what the old H G V lot used in the 70 to 80 on the older trucks and was recomended to me for the Austin that I had just got as it did not harm the bushes

Hi Hayden, Sorry for spelling your name wrong on my last post. I did raise the subject of sulphur and yellow metals erosion to the Castrol rep. on Friday, he said that there is a small amount of sulphur in the D140 as there is in all oils, but not enough to give us any problems with our axles.Ps I hope you have changed yours since the 70/80s You might have an axle full of 'snot' like me!

Have been in touch with Castrol. D140 in not a detergent oil.