304 Rear main seal on 5.0 V8

[Kingswoods rule]

Hi guys, I'm not a commodore head (yet) but get into all things Holden anyway, hope you will excuse that! I had a rear main seal that persisted in leaking after changing it 3 times, tried different part numbers, everything. A mechanic told me that the lips of the seal eventually chew a line into the crankshaft itself. No amount of seal changing or stopleaks will fix it. He said this is such a common problem that both Holden and Ford have had aftermarket sleeves made available. A sleeve is machined into a cylindrical/tube like shape, then slipped over the end of the crankshaft. The crankshaft holds the sleeve on (interference fit for you tech heads) and it runs against the lip of the oil seal itself. It is really thin so doesn't affect tolerances/clearances. You can polish out the rut in the crankshaft with emery cloth too, but it's a pain in the ass. I was not able to find a sleeve off the shelf, but I have a mate with a lathe make one out if chromolly for me and it still works after 100.000kms. If that fails you can always adopt my motto "Holden - helping put oil back into the ground for over 50 years" now that's environmentalism!

Cheers and good luck with it!