Better diff seal

[estutjaweh]

Hi all.

So my chimp is now in hibernation until March so I have a little time to sort some stuff out. One thing that desperately needs attention is the diff as I've been putting this off for about 3 years now.

The diff is leaking oil on between the silver adjustment part behind the drive shaft and the housing itself. The oil is seemingly creeping through the thread where these are screwed together. It's definitely not the seals - I've replaced those the first time I took a look at it.

Does anyone know what sort of thread sealant is used between these adjuster silver bits (see photo below) and the housing? Do you think it should be possible to unscrew the silver part a little, add sealant and re-screw this in with the diff in situ (obviously marking and ensuring I screw it back to the exact position it was previously)? As the car is off the road until March (German season number plates), I am unable to get to a garage with a ramp.

Any help/advice is greatly appreciated.

[Sardonicus]

If your positive that it is leaking between that housing and the diff casing I would jack up tat side only degrease that void/join with brake cleaner and a toothbrush allow to evaporate thoroughly and then fill void with RTV sealant smoothing into the joint with a wet/spit finger it may sound like a bodge but trust me it will work and is a lot less hassle that the other alternative which may end up causing more harm than good I have done this many a time on FWD gearboxes that don't use gaskets but sealer where the only alternative to cure is to remove strip/split casing and reseal the labour difference is staggering and the customer is grateful

[estutjaweh]

Thanks.
I thought it was the seal originally and so stripped it down to the stage in the photo 2 years ago. I replaced the seals with new ones after having degreased the whole lot and the oil leak continued as if I hadn't done anything. It's definitely coming from between the two parts rather than the seal itself.

Is there a particular brand of sealant you would recommend? And just to clarify, you would smear this outside on the area rather than unscrew the silver part slightly and apply to the thread? This oil leak was a problem getting through the MOT so I need to do something about it but the diff isn't loud so I feel a complete strip down and rebuild is overkill at this stage.

Thanks for the tip.

[Sardonicus]

RTV is the bks for this kind of deal but oil/grease free surfaces are imperative.

[Mr Supercharged]

Alternatively you could use Loctite 577. This is what I use on threaded joints. You need to consider that whatever you use could potentially make disassembly more difficult should you ever need to do so. As previously said you need to make sure that both surfaces are perfectly clean and dry before applying sealant, I use acetone from our lab, nail varnish remover is the nearest equivalent. Brake cleaner or carb / choke cleaner are also possible. Other solvents often leave a greasy residue that will prevent a good seal.