Gearbox question 🙋‍♂️ again 🙈

[Rmlandscapes]

Sorry folks ,
Ok i bought the motorhome and gears 1 st & reverse was tight I was in Newark and van owner convinced me gear linkage needed greasing as been sitting ! Turns out I Had to get gearbox reconditioned from a reputable company in Glasgow and I purchased a valeo clutch & thrust bearing all went in well on Friday I helped my friend who is a mechanic but after a trip away I noticed this today
It’s clear and defo gearbox oil as smell during it looks like coming from Centre of the box !
I’m right in saying if it was crankshaft seal it would be engine oil ?
Drive shaft seals be in middle ?
Any help be much appreciated

 

[Figaro]

What engine ?
May help others advise
I take it you checked the plug is tight ?

 

[Rmlandscapes]

Fiat Ducato 2.8 jtd
Plug like 50 pence shape ?
I checked drain plug and was tight

 

[Landy Andy]

Is your photo showing where the engine and bell housing join.

If yes, then the leak could be engine oil, gearbox oil, or clutch fluid

If engine oil it would be black,
If gearbox oil it should be golden colour, clean, and have a different smell
If clutch fluid it would be very very thin, but these loss more noticeable due to only small reservoir.

But if it smells like gearbox oil that is probably what it is. There will be an input seal on the gearbox, and that is what I assume has failed, or been incorrectly fitted.

Unfortunately it’s box back out to do it, and hope it’s not got oil onto the clutch plate