Differential oil leak

[Nickol]

A few weeks ago by routine maintenance I had to top up the diff oil. Not having checked it for such a long time I thought it ok that this was necessary.

Yesterday evening we drove 10km to a near village to our favourite Italiener and whilst there the owner told me that a customer had seen an oil leak coming from the RHS rear axle wheel. I went to have alokk and it was Hypoid oil from the diff immediately recognisable by the smell. No big problem I thought, the oil seal had obviously been breached and needed renewing.

This morning I had the car on the scissor lift ( what a luxury that is!) to start work but on removing the wheel, the leak was obviously not coming out of the flange/brake drum and contaminating the brakes. They were dry! It appears to be leaking from around the rear spring. This is far more worrying and hence my thread. Could it be that the rear axle at this point has broken/cracked allowing the oil to come out? Or is there a simpler explanation.

Here a couple of pics. As can be observed, the area outboard of the rear spring is dry.

IMG_1412.JPG (424.44 KiB) Viewed 4033 times

IMG_1411.JPG (455.04 KiB) Viewed 4033 times

[Bill_qaz]

Likely case corrosion around spring bed area, strip off U bolts, part axle and spring and give casing a good clean and inspection, would be my recommendation.

[mowogg]

Mine went there adjacent to the perches. I swapped the axle casing for a better one.if you are careful you can do this without stripping the brakes, by removing the back plates while you swap axles over

[Nickol]

Likely case corrosion around spring bed area, strip off U bolts, part axle and spring and give casing a good clean and inspection, would be my recommendation.

That would seem to be the best cause of action but if the axle needs replacing, then I am in trouble - will have to go to UK to source and get a replacement. But first stop, dismantling.

[philthehill]

I can sympathise with you!
The spring to axle mount is very prone to corrosion because of the dirt trap produced between the axle mount bracket and the axle casing.
This area of the axle needs to be regularly cleaned and protected with Waxoil.
I am having to replace my rear axle casing due to damage to the axle spring seat and have found it very difficult to locate and procure a serviceable axle casing.
After the third attempt I have managed to find one which is in near new condition with no rust or metal reduction around and under the saddle of the bump stop.. To find a good one is not cheap and requires detailed examination of the axle casing.
The first axle casing looked extremely good but after cleaning and applying Fertan rust remover the axle casing was found to be full of rust holes so has had to be discarded. The second axle casing looked excellent but the axle casing had been grit blasted and there was grit still trapped inside the axle casing and covered with paint. After prolonged cleaning and getting nowhere it has been put to one side for the moment. The third axle casing was found on 'e' bay and I had to go to near Heathrow to collect it. This third axle casing is excellent with good spring hangers and will be used to replace the damaged axle currently fitted to my Minor.
I would suggest that you take your time looking for the right axle and do not buy without looking/examining the axle casing as what looks ok may not be as good as you think.
ESM appear to be out of stock regarding S/H axle casings but 'simmitc' (located in Essex) contacted me after I advertised in the wanted section. He has three 1098cc axles available. It may be worth sending him a PM.
Good luck.

[Nickol]

Oje! A lot trickier than I first thought especially regarding a replacement. Anyway, first things first - will remove the U bolts etc around the area tomorrow then lets see.

[Nickol]

I have just removed the supporting U bolts etc and freed up and cleaned the axle casing, although looking at the attached pic, you would be forgiven for thinking otherwise. The flash exaggerates somewhat.

I then topped up the diff with oil and ran the car on the lift in 2nd gear for 5 minutes to determine exactly where the leak is. Nothing! Still dry.
I suppose I should run it for much longer to get everything to warm up? If and when there is a pinhole or crack to be seen, is there a way of fixing it by welding or other means?

....having attached the picture it seems there is a small dark spot , possibly a hole.....shown by hte arrow. I will post the pic and then have look again.

IMG_1415.JPG (302.4 KiB) Viewed 3898 times

IMG_1414.JPG (365.77 KiB) Viewed 3898 times

[Nickol]

Yes!

Just poked a screwdriver into the black spot which is indeed a hole and have now enlarged it a bit. Quite thin steel. It is in a position where to my mind it will be possible to weld a plate over it albeit I think the MIG welder in my hands will not be the solution. But is this feasible idea?

[les]

I would think welding around that area would likely blow a hole elsewhere. I suppose you’ve nothing to loose if you try but
I’m sure you would rather have a better axle despite the hassle involved.

[Nickol]

Definately a better axle is the optimum solution. That presupposes a new one can be sourced or an old one less corroded. As a thought, the supporting cradle was welded on to the casing , albeit was shiny new at the time. I think I will polish around the spot to see if I can expose bare metal. That would be a precurser for welding anyway.

[philthehill]

My advice to you is to ditch the axle casing and fit a new to you casing.
Those axle saddles/mounts are not fit for purpose.
Welding will just expose more holes.
I would approach Simmitc and enquire as to the condition of the axle casings he has. He may be able to send you some photos.
As you have the lift - changing the axle is no big deal and at around 4 hours will be well spent.
Build up the axle before fitting.

[Myrtles Man]

Plastic metal worth a try?

[Nickol]

Its well worth a try, thankyou for the idea. A bit of a bodge perhaps but over piece of thin steel covering the hole

[philthehill]

A bodge would be an understatement. That axle has had it.
You could find that the axle breaks in two at the bracket and the vehicle is thrown off the road.
I will be quite blunt - if you continue to use that axle in its present state (bodged repair or not) you are putting yourself and others in harms way.
It is up to you what you do but I certainly would not admit to having bodged the mount/axle casing
Below is what it should look like and not a bodge in sight.

axle 2.JPG (117.34 KiB) Viewed 3837 times

[Bill_qaz]

Phil is correct if you now have an accident due to structural failure you are probably uninsured and liable. You have publicly posted the defect, you would be surprised what investigators can unearth.

[Nickol]

A stern warning indeed. Let us hope I can procure a new one sometime.