Why do I keep chewing out cam synchronizers in my AU II XR8 5.0lt falcon. I have now replaced it 3 times in the last 4 months as it keeps squealing on cold start

Are you replacing them with good quality ones? - Hows the oil in the engine?

You can take them to an auto electrician and they can rebuild the synchroniser as its just a short dizzy...

Yes they're all good quality and two of them are OEM specs. I also change the oil every 5,000 with full synthetic 5w-30 best I can buy.

Righto then. Seems like you have it all covered.

The squeeling comes down to the bush/bearing in the synchroniser. You dont have an alignment problem do you

Might be worthwhile removing the collar on the sync sensor shaft just below the alloy housing. I assume it's purpose is to limit oil getting up the housing since the cam sync sensor shaft will naturally be pulled downwards into the block when the engine is running. Maybe it's working too well and no oil is getting where it's needed???

Strange that the TFI dizzys with the same design didn't have any problems. But the sync sensors squeeling are a common occurence

There is a tried and proven method for fixing the common squealing problem.
Here's how I do it...
Remove the coil pack assembly
Unplug the sensor then unscrew the two retaining screws
Once removed pour a small amount of oil into the syncroniser and let it soak in for a couple of hours
Put everything back and start the car. Depending on how long the squeal has been there for you may require a new syncroniser. If it's caught early enough you can use my method and prolong the life of your existing syncroniser.