On Td and Tdi there is a 'keep' for when the plug is not in use

So, if we intend to cross, and therefore wade though, deep water, we must plug this hole first with the appropriate wading plug. Until mid 1992, or thereabouts, this took the shape of a tapered threaded plug with a square head. On newer vehicles use a parallel thread plug, which has a flange to stop it being screwed into too far. This flanged type has a traditional hexagonal head.

On all later four-cylinder diesel engines including the Tdi, there is a threaded hole also in the bottom of the timing case cover that is there to allow any oil to escape from a poor front crankshaft seal. This is only applicable to engines fitted with a timing belt as opposed to a timing chain. The plug which we always install here is the parallel threaded type with a flange and hexagonal head.

Both these plugs must be inserted before wading to stop the ingress of muddy water that could seriously affect either the clutch or timing belt. We must not, however, leave these plugs installed because, when wading constantly through deep water, water can still get into these housings through surrounding poor gaskets and the last thing we want to do is to trap water, or come to that oil or clutch fluid, should there be a problem.

It is, therefore, essential to remove the bell housing wading plug, and timing case wading plug (if fitted on your vehicle) on the return journey from every off-road journey. If water does run out you know that you have a poor gasket, probably because the engine or gearbox has been removed, or timing case cover refitted without using Blue Hylomar sealer. No problem, but just remember it. If oil comes out, one day soon you could be having the oil seals replaced!

Index [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]

(c)Goodwinch Limited 2006