Rear Main Seal

Removing the flywheel won't damage the seal, so you can use it again. Replacing the pressure plate isn't necessary IMO, if it is not worn. Only the friction disk needs to be replaced if it is contaminated with oil. Clean the flywheel and pressure plate with a degreaser to remove eny traces of oil, and unpolish the surfaces with abrasive paper. Check that the O-ring inside the flywheel was installed properly and that it was in good condition. This might be leaking, and oil that leaks past this o-ring eventually reaches the friction disk. This O-ring (graphite coated) usually comes allready damaged in many engine gasket sets, so you have to buy 2-3 sets to get a good ring. Oil it slightly before installation. This ring needs to be replaced every time you reinstall the flywheel.

Bill, '67 Bug.

"Front" seal. I would be OK with re-using it. More likely to be damaged is the O-ring seal inside the flywheel; definitely replace that. And double check the crank endplay afterward.

Before you go thru all this bother, check the tranny mounts; a broken/worn mount will cause clutch chatter.

Speedy Jim

On Mon, 22 Nov 2004 17:48:01 +0200, "Kevin" scribbled this interesting note:

Let me get this straight...

Someone built or rebuilt an engine yet used the same damaged clutch plate upon installation? No offense, but what else was reused that shouldn't have been?

To answer your question, if the main oil seal (which is on the front of the engine as it is installed in the car) isn't leaking, removal and reinstallation of the flywheel should not cause any damage.

Balancing the pressure plate, clutch plate, and flywheel as a unit is good, but when the engine was being worked on, those, as well as the crank and pulley should have been balanced as a unit if you are concerned about balancing issues.

But really, why go to the trouble of building an engine and then try to save a few pennies by not using a new clutch? It isn't as if they are all that expensive. As a percentage of the cost of doing a proper build, it is very, very little. This is becoming my mantra these days...You have to know which pennies to pinch!:~)

Look here:

-- John Willis (Remove the Primes before e-mailing me)

Hello Jim (and others) I just had my flywheel of for replace the main seal. I did not notice the O-ring you talk about. Where should it be? On the flywheel?

The engine is still out... :-) Bye from Denmark....Michael (1303 from 1974)

On Mon, 22 Nov 2004 17:31:12 +0100, "MIC" scribbled this interesting note:

Inside. In a machined in groove. Take a peak.

-- John Willis (Remove the Primes before e-mailing me)

Beginning with the 1300cc engine, a groove was cut *inside* the hub of the flywheel. An O-Ring slips in the groove and seals the flywheel hub to the crankshaft. On earlier engines, sealing was done with paper or metal gaskets between flywheel and crank.

As Bill noted, the O-Ring is often received damaged or gets damaged when the flywheel is installed on the crank. The O-Ring has to be installed with care. Use of lubricant will help prevent distortion.

Speedy Jim

Thanks guys for all the quick Reponses. I have checked tranny mounts, they are fine that's why I suspect the clutch plate. I will replace the o-ring.

I don't take offense it wasn't me who rebuilt it, nor knew what was being reused. The spark plugs, points, condenser and the clutch plate to my knowledge were things that were reused; I was a bit disappointed at this but it was a really cheap deal and while my original single port lies in wait for a rebuild by my hands; this engine will have to do. I agree replace these maintenance parts while spending on the engine, but I only discovered it a while after the engine had been installed when I couldn't find my clutch plate I realised it was on the engine. The plugs and leads were also reused, but have since been replaced along with pitted points and a maintenance that I didn't quite trust.

Thanks for all the responses Regards Kevin

Given the relatively minor cost of the front main seal, and the fact that you have to remove the engine, clutch, and flywheel to replace it, wouldn't you just kick yourself if you get it back together with the old seal, get it running perfectly, and then discover a dribble from the front of the engine?

The seal is like 5 bucks..replace it while the opportunity presents itself and double-check your endplay while you're at it.

My 2 cents worth...good luck with it.

Chris