Timing cover oil seal

[BI8759]

Is the timing cover oil seal something that needs to be changed? I'm going to put a duplex chain on and the kit comes with the seal. If so, how do I get it in and out ? Sorry if this is a stupid question but Haynes is strangely silent and the Leyland manual talks about special tools.

I can't really tell if it has been leaking to the generally oily filthy state of the engine

[bmcecosse]

Yes it must be changed - careful taps from inside to out with a large screwdriver.. Special tools in the Leyland Manual....hmmm BTW - Have you measured the 940 head to make sure the valves don't foul the block?

[BI8759]

Wow, that was a laugh a minute; simultaneously rock hard and brittle. Still got a couple of fingers left.

Yes, I know about the head, it's been on for a wee while now. I changed heads because the engine was smoking like a smoky thing. That didn't cure it so I'm assuming the oil is getting around the piston rings.

[IslipMinor]

When you refit the timing cover it is best to use a light smear of gasket sealant on the gasket between the gasket and the cover itself and a smear of grease between the other side of the gasket and the front engine plate. The idea being that the face of the cover is not a nice flat machined surface, so needs a little bit of help to seal, whereas the front engine plate should be flat, so the gasket will seal nicely! The smear of grease helps it seal and also helps it centre on the oil seal.

To give the gasket a fighting chance to seal, the face of the timing cover must be flat. Whether there is a problem or not, will depend on how many times it has been removed and refitted. If the cover has been distorted around the screw holes, it is well worth tapping the area around the hole flat before refitting it.

The timing cover setscrews should be fitted with an oval shaped washer next to the cover, and a spring washer between the oval washer and the setcrew head. If an oval washer is missing, a flat washer is better than nothing.

The oil thrower ring should have 'Front' stamped on it, and it must be fitted the right way round.

Also to make sure that the oil seal is properly concentric with the crankshaft pulley, put the cover in place and fit one screw on opposite sides of the cover very loosely, then slide the crankshaft pulley on and tighten the nut, then fit all the rest of the timing cover bolts loosely, then tighten them up.

[bmcecosse]

Seriously - this has been covered over and over again - please don't mess up your engine with gasket sealant. BMC didn't use it - you don't need it now. It's a bodge....... The timing cover gasket is nice and thick and will take up any slight undulations in the cover.

[IslipMinor]

As has also be said before - each to their own!

When BMC first assembled the engine, the timing cover was also brand new and nice and flat. Now 30/40/50 years on??

[les]

I don't think sealant will mess up an engine, applied sensibly of course! In fact I thought islipMinor/Richard gave a pretty good description of a successful cover replacement, including those oval washers! It's a fact that many covers have suffered distortion since the factory fitted them.

[bmcecosse]

Oh yes - everything is spot on - except the sealant...... Trust me - you don't need sealant!!

[chesney]

To throw it in the mix, I recently replaced the timing chain on my 950, didn't use any sealant (just gasket). It is about the only bit of the engine that doesn't leak oil

[brixtonmorris]

I put the pully wheel into the oil seal first,(oil seal already fitted to the cover) and them put the pully wheel on the crank, do the bolts up on the cover. It will always be centered then. I have turned a tool to extract and insert the oil seal using a bench vice. It supports the cover as it extracts and inserts the oil seal. can make more if any one wants one.

[IslipMinor]

I put the pully wheel into the oil seal first

I like that idea, I will try it next time I have to replace the seal.

[bmcecosse]

It is the way I have always done it too - although using a damper, not a pulley.

[BI8759]

Many thanks for all the advice. The timing cover looks remarkably straight and the gasket is absolutely glued to it

[brixtonmorris]

It is the way I have always done it too - although using a damper, not a pulley.

What do you mean damper bmc?

[bmcecosse]

Crankshaft damper - fitted to all later A series - helps to stop the crank breaking!
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