TD5 rear crankshaft seal or rear sump gasket leak

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rockjunky

Member
Posts
57
Location
lincolnshire
I have an oil leak that's slowly getting worse. Its showing on the 2 lower bellhousing to engine/sump bolts.

looks, feels and smells like engine oil and not gearbox or diesel fuel. The rear camshaft seal is also dry. There bellhousing looks dry above the bolts. Can't see any other leak around the sump gasket.

i have removed the bellhousing lower wading plug, its wet inside. I have stuck a borescope in to see if i can check if the leak is the crank seal of rear sump to engine seal, but i cant get a clear view to be sure. i suspect if either are leaking then due to clutch/flywheel whirl then leak from either location would result in everything getting wet.

Has anyone got any advice/tips on how to check if its crack seal or sump gasket? as i really don't want to pull the gearbox to change crack seal if its only the sump gasket. i could just try sump first but could be wasting new oil if it turns out to be crank seal.

Photos below.. i had cleaned the oil off the bolt heads before i took the photo. Also the borescope pics that show yellow oil staining on the sump is not wet oil, i think its actually STAGG WELLSEAL. last time i change the sump gasket i painted both mating surfaces with it, helped keep gasket in place and provides some extra seal, its not thick like RTV, juts paint on thin layer on the face. I also did put RTV as per manual in the front and rear locations where the casings joints are to seal the steps, and torqued the bolts in the order given in the manual. All that said i was never that confident that sump gasket seated correctly at the rear, i found it a right arse to fit when laying on the floor.

in the photos you can just see a tiny bit of the sump seal edge poking out, not sure if this is normal or if this means the gasket isn't seated correctly. maybe a 2mm.

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