Chain Guard Gaskets

My chain housings have been wet for as long as I can remember. You can read about this here. They don't actually leak or drip and even weep would be over stressing it but seeing as the whole of the rear is stripped it seemed like agood opportunity to fit new gaskets and new rubber washers.

This is a very common place for leaks and because of the large amount of labour required to get the covers off many people first of all try re-torquing all the screws or even changing the ones they can get to. Like the lower valve covers, oil can leak through the rubber seals behind the domed thrust washers if the rubber has deteriorated. Tightening up or changing the screws will often solve a small weep here but in my case I have the temporary luxury of full access so a new gasket and a cleanup seems in order.

Here is the view with the rear PU, silencers, heatshields, catalyst and engine carrier off. The engine is also dropped a little. You can read about how to get to this stage in my cat bypass page. The engine carrier needs to come out as well so you can pull the compressor support bracket forward. The guide for the engine carrier removal (and heater tube) is here.

You have 9 screws to undo on either side. They should be very easy to get off. On the LHS cover there is just one hidden behind the base of the distributor but that's no problem at all for access with a regular spanner.

On the offside you have a small heatshield and then you have one screw that sits completely behind the AC compressor support bracket. You have to unfasten this support bracket from the crankcase and then pull it forward as much as you can (it has two lugs on its inner face so actually cannot be moved off entirely because these lugs or tabs hit the crank pulley. You have to take off the crank bolt and crank pulley if yu ever want to remove it completely).

One screw here.

And an allen head here and then yank the whole bracket forward, tilting its RHS more toward you than the LHS.

Remove the chain housing cover screws one by one. Some of them will come out alone leaving the rubber washer still stuck on the chain housing cover. Inspect the seals carefully for deterioration. A full set of the screws,thrust washers and seals comes to over £120 so i'll be plating mine and replacing just the rubber seals that are looking poorly and all the lower ones by default.

Take off the long rubber strip that runs across the face of the cover.

Prise off the cover and have a pan below to catch any oil.

You'll want to clean the mating surface that the gasket presses against.

I used tissue held back onto the lower inner corner with one screw. This stopped them leaking whilst I was at work.

I actually used some glass polish here to bring the surface back good and get it nice and smooth. A nylon gasket scraper is a nice idea too.

Same with the other side.

Here is the old gasket. Crumbling and pretty manky. Looking through my service record I guess this is 15 years old !

Giving the covers a good soak and degrease.

New gaskets, loctite 574, plated screws and new rubber seals

Oil the underside of the gasket

Pop it in

Apply abead of loctite onto the seal area. I did this on the gasket rather than the gasket face as it was easier to work out where to put it.

A full set of new screws, caps and rubber gaskets comes to over £140 ! So I plated everything (that cost £50 along with a ton of other screws, washers, bolts & brackets from my rear overhaul project and my entire collection of rear suspensoin bolts). For the rubber seals I got 6 new ones for the 3 lower screws each side. The leaks come from here so I thought it better to repace the rubber in these lower ones. The other seals I gave a good clean as you can see in the picture.

Pop the cover back on ...

Torque to 9NM

Job done.

To complete, simply reattach your cataylst, heater tube, silencers, heatshileds, bumper, rear PU etc..