Td5 D2 - Engine Undertray plugs.

There are a couple of pre-formed plastic 'undertrays' attached to the lower surfaces of the forward chassis.

The design of these 'trays' appears to be multi-functional. They cover the lower engine bay directing the flow of air under the vehicle and shield the engine bay from road spray. In addition the upper surface is coated in closed-cell foam that provides a degree of sound and temperature insulation as well as functioning as a 'drip-tray' to catch any small fluid leaks from the engine that would otherwise stain the road/driveway surface beneath the engine.

Image above shows the downward face of the pre-formed tray that attaches to the chassis below the engine compartment. 

Access to the drain plugs for the engine oil and the cooling system is via two removable circular 'plugs' which can be seen in the above photo.

The circular 'plug' that allows access to the engine oil sump has been removed, but the access cover for the cooling system drain plug is still attached.

Once removed, these plugs are often discarded and never replaced! The method of attachment is a simple twisting 'bayonet' function.

This is a photo of the upper surface of the undertray plug. Comparison of the two photos shows their method of attachment. They are large 'plugs' each with a diameter of 19 cm.

Opinions about the credibility of the fitted undertrays can differ. They can be labelled 'superfluous'. They restrict access (physical and visual) from below to the engine bay components and with extreme off-road use can easily get damaged, cracked or dislodged by debre, wading or mud plugging. It's not an easy task to remove them either. Their fitted position above the axle but below the engine makes removal awkward and a lot are simply destroyed during removal.

Hx still has them securely fitted although both of the circular plugs have always been absent since ownership began. Indeed, I can recall wondering initially, why the undertray should have two big circular holes in it in the first place! 

Recent work to the cooling system on Hx required access to the coolant drain plug and that focused my attention on the missing cover. I decided to source some replacements or have a go at fabricating some.

That well known online auction site (where I sourced the above photos) prices them used at around £30. I decided to have a go at fabricating some covers from scratch for free.

The initial sketch plan and the first template about to be cut from card...

The template was refined and fabrication begun. I used the lids and bases from suitable waste plastic tubs.... All cutting was done freehand with the craft knife (careful!)

Offcuts of closed-cell foam were attached to the inner face and a locating handle secured to the outer face..

The finished plugs, and they fit! 

Really needed that 'handle' to help twist them into a locked position, a bit hit and miss but they have stayed on (so far) ..