Common stainless steel alloy fasteners such as 304SS / 316SS are bad for galling, essentially the metal on metal micro welds itself on same grades,

but to some degree using different grades the effect can be reduced. Not great in strength either but there are stainless alloy grades that could possibly be made and in some cases heat treated. In regular steel fasteners 4.6, 8.8, 10.9 and 12.9 are grades of strength - 8.8 with zinc coating should be fine. Torque wrench is good as well as either locktite, spring washers or antiseize pending application. Lots of older jap cars seem to use a lot of 8.8 zinc plated with one size finer thread than the std coarse and use a smaller metric head size rather than imperial. Theres a lot more to all this but thats a start anyway, hope its of some use :P

Edited November 20, 201312 yr by styler

Geez it turned into a quantum mechanics argument....

When you get your bolts and lock washers all sorted out...it's a thick rubber gasket...put a very thin coat of RTV on it, plus what you put on the round ends....finger tight all the nuts, then keep your eye on it and just tighten it til the rubber squeezes out just a tad, (maybe a micro tad, I'm not sure if an Aussie tad is the same as over here.) :)

If sump bolts get stripped out, something terribly wrong is being done....

if its only a couple of them, no worries! just go overboard with the gasket goo ;)

Ended up pulling out and replacing all but 6 studs (for gasket alignment) with 8.8 grade bolts and stainless spring washers from Auto1, put a new gasket with a bit of rtv black on either side. Also redid the cam cover sealant timing seal for peace of mind. Did the sump up as Corolla Nut said, watching for the gasket to squish out just a metric tad or 2.43 imperial tads ;) No more leaks now :)

 

For anyone searching this thread for information, the thread is M6, you need about a 15mm long bolt and at least 22 bolts/nuts/studs/washers (There is another sump gasket for the 4kc Auto1 sells with 18 bolts so I'm guessing there are two sump bolt patterns)

Yep correct, 3k and 4k+ run different sump bolt patterns.

BTW I like to grub screw for a stud the timing cover, this enables easy sump gasket install, and If we need to change cams, just take the grub screws out with allen key.

Maybe its different on a 3k, but on a 4/5k the timing cover has an inner lip and I tried and couldn't get the cover back on with out lowering the sump. My cover had bolts going into the cover so the studs weren't a problem.

The 4k timing cover has larger bolts, not sure about the studs, Interesting don't seem to have a problem with the 3k.

Cheers Andy