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Discussion Starter · #1 ·
I have a 1980 308 GTSi which i

I have a 1980 308 GTSi which is leaking oil profusely. Upon removal of the rear timing belt cover, I discovered that the gear which drives the timing belt wobbles while the engine is running.
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timing gear leak
308 engine front2.bmp (2229.7 k)</td></tr></table></center>
(picture borrowed from forum)

This is now leaking and throwing oil everywhere. A few questions: 1. What would cause the gear to wobble? The engine still runs great but does sound like something is grinding in that area. My guess is a bad bearing.
2. What turns that gear? This is the first overhead cam engine I've worked on so I'm a bit concerned that something could be bent.
3. How is the gear removed and what tool is required? It's something I've never seen before.
4. What needs to be removed in order to remove this cover? There are studs in the bottom as well, right? Do you just pull the bottom studs (if that's even possible)? I am planning to do this, on the car without removing the engine.
5. I'm assuming since I'm removing timing belts, that I would want to move #1 to TDC before disassembly. How do I know when I've hit TDC and if it's the correct TDC cycle?

Any pics or further instructions are greatly appreciated, as well as sources for the replacement bearings, seals and gaskets (and anything else I may need)



Discussion Starter · #2 ·
Wow, you don't have an eas

Wow, you don't have an easy task facing you, if the picture describes where you have to go.

First, you'll have to set the Engine on TDC & pull the crank pulley (and might as well replace the crank pulley seal while you're there).

To set the engine to TDC pull the oil filler cap & the plate under the Oil Pressure (under the Oil Filter) sender at the flywheel side.

With a very good flashlight peer into the Oil Filler Hole & turn the engine over until the Cam Notch aligns with the Cam Bearing Mark....(if you are not positive, do this several times until you are). Once you have turned the engine over until you are positive the Cam Marks Align (as viewed thru the oil filler hole) then check that the Flywheel is aligned at 1-4 PMS thru the hole under the Oil Filter. Once you are sure both of these markers are in accord, then the engine is at TDC #1.

At this point you can mark both cams & covers with a paint mark that is small & presice. Once marked the Crank Pulley can be removed & the belt tensioner can be relaxed and the belt removed.

To remove the Castelated Nut on the Cam Belt Drive Gear you will need a Special Socket from GT CAR Parts in Ariz.,(Bill or Dave will know exactly what you need). You will also need at a minimum the outer bearing & seal, (which they will also know about) and the Inner Bearing.

Sorry, but here comes the real ugly part......if the pulley is damaged you will need a new one (which GT can supply), and if the inner bearing is shot and not just the outer bearing you will have a very difficult but doable job of replacing both bearings. To pull these bearings requires an Inside Bearing Puller, which I would hope you are familiar with for this operation. Sometimes the Inside Bearing is still ok, as most of the load is on the outside bearing, however, after the removal of the outside bearing the inner bearing wear must be determined...this pretty much requires someone that knows the difference between good & bad & requires a judgement call.

After the neccesary parts are replaced, in the reverse order of disassembly, reassemble. Making sure to check all marks. Once you are sure all marks align properly turn the engine over by hand several times & recheck (adjust marks & belt tension as neccesary, until perfect).

Be Careful with all the Seal Lips that touch moving parts and lube these lips with oil or grease after instalation of the Seal, but before instalation of a Pulley to prevent galling. Also note that a pulley with a severe groove where the old seal was riding is likely no longer a good candidate for reuse.

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