oil leak

[Dippydog]

Had step daughters car for an M.o.T. yesterday[failed on n/s bottom balljoint]tester did note a slight oil leak from the bottom of the bell housing.As it's completely dry everywhere except the very bottom the leak must be coming from inside the bell housing.Given that the engine isn't losing oil I've more or less[but I'm willing to be told differently]ruled out rear crank seal or the core plug[does the petrol engine have this?]so the only other thing I can think of is the gearbox input shaft seal.I'll check gearbox oil level when I put on the track control arm.If it is the input shaft seal does anyone know the part number?Car is a 2001 2.4lpt petrol manual although the gearbox is a replacement from an older car and is I believe an M54 or possibly M56[I'll have to check that]Skandix seems to list two seals both of which it terms input seals but they have different diameters so i don't know if I'm looking at the right thing there.Would one of those seal swelling additives added to the gearbox oil do any harm/good?

[Lancee]

Could it be brake fluid from the clutch slave cylinder weeping/leaking ?

[Luxobarge]

My money would still be on crank main seal, just because it's not gushing out doesn't mean the seal isn't a bit worn and weeping.....

[Dippydog]

The only reason I'm leaning towards input shaft seal on gearbox is that the engine isn't losing oil[she checks the levels religiously once a week]and the brake/clutch fluid reservoir is still full.However at this stage I'm not discounting anything and will have a more detailed look once the new bottom arm arrives and I go to fit it.But thanks for replies.

[ITSv40]

Originally Posted by Luxobarge

My money would still be on crank main seal, just because it's not gushing out doesn't mean the seal isn't a bit worn and weeping.....

As above ^^^^^^^

A slight weep will make the bell housing wet. It would need to be dripping on the garage floor to make any difference on the dipstick.

[DaveNP]

If you're checking the gearbox and engine oil levels have a sniff of what they each smell like, to me gearbox oil often has a more acrid smell, if you check the smell of the oil that is leaking you might get a clue where it's coming from.
My car has leaked engine oil from the gap at the bottom of the bell housing for years not a massive amount so I've left it alone.

[IainG]

Hi
My V50 was picked up with the same. It is only a damp patch on the bell housing. I was told it was the crank shaft oil seal weeping. Not very worried as it doesn't seem to be affecting the clutch and my oil level stays the same. If it got worse or the clutch started playing up that would be the time to do it. New clutch and crankshaft oil seal at the same time??

[Clan]

Originally Posted by Dippydog

The only reason I'm leaning towards input shaft seal on gearbox is that the engine isn't losing oil[she checks the levels religiously once a week]and the brake/clutch fluid reservoir is still full.However at this stage I'm not discounting anything and will have a more detailed look once the new bottom arm arrives and I go to fit it.But thanks for replies.

it is very rare to find a crankshaft rear seal leak whatever the age or mileage. That's why I never change them if doing a clutch and they are dry. Fitting a new one is more likely to leak !