Thread: Ashcroft HD CV shafts and front diff seals - leaking?

Originally Posted by Tombie

There are 3 sealing points on the oil seal, 1 internal (keeps oil in)

which is this lip with the spring fitted:



As far as I understand the wavy pattern moulded into the lip (visible on the next picture below) has a purpose is assisting the lip to seal.

Originally Posted by Tombie

1 external (keeps dust and water out) and the 3rd external is to keep dust away from the main external face.

It (the outer soft face) isnt there to stop any grease or oil.

Visible in this picture:



and this is the collar on the driveshaft that the outter dust seal goes against:

This morning I pulled apart the front passenger side which had the worst leak:



Leaked oil all over the inside of the tyre:



Pool of leaked oil on the bottom of the steering knuckle:








The ball joints look to me like they are in good condition - there is no damage to the rubber boots and I cannot feel any play.

Upper:




Lower:





The bearing in the wheel hub seems to still be good - I cannot feel any play and it doesn't cause the three amigos issue.


The garage supervisor provided no assistance:





Upon eventually reaching the seal it became obvious why it was leaking:










What I'm unsure about is what caused the damage to the seal!?!

I thought perhaps I have not fitted the collar to the Ashcroft drive shaft low enough to protect the seal?

Details of another users experiences - http://www.aulro.com/afvb/showthread...70#post2197870

I've seen that type of failure on standard axles. I replaced the driveshaft seals on my disco when I replaced the balljoints, as a preventative measure. Used genuine seals, only to have both sides leaking within 2000 km, the left one badly so.

Upon dismantling, the centre section was completely detached, and sitting inside the diff housing. Having NEVER seen any sort of seal fail like this, I inspected everything very carefully. Long story short, I happened to still have my original seals (factory fitted, I'd guess) sitting in the bin, and when I measured them against the new genuine ones I'd got to replace the new leaking ones, I discovered the new ones were about 1mm smaller in all diameters through the middle of the seal - including the parts that should never touch the axle, what I would term the 'clearance diameter'. Which meant that this section which shouldn't actually touch the axle (outboard of the spring loaded sealing lip) was actually the same diameter as the axle itself, and making contact. No oil should get past the lip to that point, so you have dry rubber with steel rubbing against it - no wonder it ripped the guts out of the seal.

So I'd suggest anyone replacing driveshaft seals should measure the 'clearance' ID of the seal, and ensure it's 36mm or larger - 1mm larger than the 35mm of the standard axle sealing surface. Inside the lip should be about 32mm with no pressure applied to verniers. Genuine seals with 'made in India' on the packet will probably be wrong. I have some 'NAK' branded seals sitting here which are the correct dimensions, not sure which distributor they come through, but I got them from Ritters. Haven't actually fitted them to my car yet, as I didn't damage the original seals when I pulled them out, and they weren't leaking, so I cleaned them up and refitted in preference to the new genuines I had at the time - and guess what, they're still not leaking 6,000km later.

However, I did dads balljoints a couple of weeks after mine, with the same genuine seals, and his failed in exactly the same way and timeframe. He fitted the 'NAK' brand replacements, and hasn't mentioned any problems yet, I would say he'd have minimum of 7500km on them by now.

Thanks for the very informative post and useful pictures.

I've learned more about balljoints and driveshafts in the past 10 minutes than I knew previously!

BTW, your garage is too tidy...

Yes i have the same problem, found if you keep the oil capacity to about 1.7 litres in the diff the leak is not so bad. If you have ashcroft heavy duty CV i found that IVECO have a very good heavy rubber boot to fit the CVs.

this thing is the nightmare of my life...i've never had oil leaks there, was dry as a bone for years...untill i fitted that expensive HD drive shaft + CV kit ... fitted them as they came first, starter to leak next day, thought it's cos they dont have those mud-shields, removed them from the old shafts managed to fit them on the new ones, put new seals...same story, checked the drain pipes to not be clogged - clear, replaced all the ball joints with new lemforder, no joy, put two new hubs(albeit the ones on the car were not old - all Timken type), same story... removed the whole thing and bought new hardy spicer drive shafts, now it doesnt last more than 1000Km and starts leaking... in the last year i've replaced at least a dozen pair of seals of all kinds from genuine, corteco to bearmach, allmakes even tried with some no name seals from a specialised store where i bought them by dimensions(atrangely these lasted the most)... i'm out of ideas now i'm thinking to buy a complete front axle from a breaker cos i found a low mileage one at good price...and all this saga has begun when i removed the old shafts and fitted those HD ones... that's my luck

Originally Posted by sierrafery

fitted them as they came first, starter to leak next day, thought it's cos they dont have those mud-shields, removed them from the old shafts managed to fit them on the new ones, put new seals...

The included instructions clearly stated to remove the shields from your old units and fit to the new. It is not surprising that they leaked without the shields as the oil seal seals on the shaft part of the shield. See my pictures earlier in this thread for more on this.
I am amazed that for the price Ashcroft still do not supply the shields fitted.

Have you checked the condition of your shields? Are they true or did they get bent/damaged during removal and refitting?
Have you installed them the correct way around?
Have you installed them in the correct position? The largest lip of the oil seal seals against the shield too in order to stop dust/dirt entering and damaging the shield. If you have the shield installed too far out (too close to the hub) it will allow this dirt and dust to get past and damage the oil seal.

The point raised by EvilGTV regarding the oil seal sizing may be applicable in your case too.