3.8 Diff Output Shaft - Help needed Please

[kingzetts]

I have had to remove the IRS to tackle an oil leak from the LHS diff output shaft oil seal on my 1962 3.8

There is no obvious reason for the leak, the oil seal seems in good order and is only 12 months old, the body of the output flange onto which the seal lip seats is smooth and although there is a shiny ring there is no grooving. I'm pretty sure the leak is not from between the output shaft bearing housing and the diff body where there is an O-ring, but from the oil seal itself. So to some extent I'm grasping at straws.

I have two questions to which I am struggling to find an answer in the usual sources;

First, what is the torque specification for the large nut holding the diff output flange onto the drive shaft?

Second, under this nut there is a thick dished washer. Should the washer be located with the domed face facing inwards towards the output flange body, or outwards towards the backside of the nut?

And finally your opinions please on whether oil can seep along the splines on the output shaft and weep out from under the nut/washer combo mentioned above, so is it worth putting some sealant on the splines?

Thanks in advance

[Heuer]

Have you checked the diff breather is clear? Mine was blocked and caused a leak from the LHS output shaft.

[kingzetts]

I have - in fact fitted a new breather last time the IRS was out 12 months ago.

I should add my diff is the type with the output flanges held onto the output shafts with an external nut, not the internal type recently described in a thread by Rory.

[Heuer]

You could give Ken Verity a call. Mention my name and the Forum and see if he can give you some advice. He recently sorted out the leak on my IRS after I had all but given up.

[kingzetts]

David,
Thanks for the suggestion. I called Ken and although helpful we have not yet bottomed the issue.

He did answer my question about the torque on the nut - "B####y tight", he uses a hammer rather than a torque wrench!

[steve3.8]

John ,

i would ring either Ward Axles or AJS engineering they both deal with diff's as their main line of work , they will give you the correct info .

[tinworm]

Leather or rubber seal ?

[kingzetts]

Steve,Thanks, good suggestion.

The seal is a plastic sprung lip seal - this is the output shaft not the pinion input shaft.

[tinworm]

(!) Er yes, I am talking about the output shafts - the early cars had leather seals here which changed to modern lip type seals during ( I think) 3.8 production, a 1961 car I owned some years ago had them. As you have not heard of this I will assume you have lip seals fitted and as my advice would have only been about the leather type I have nothing more to add.

Barrie

[kingzetts]

Ah-sorry, Barry, I did not realise leather seals had ever been used on the output shafts. You live and learn - thanks for educating me on this one.