No more timing case gaskets

[colin86325]

My timing case was leaking again after being resealed with BMW paper gaskets about 3-4 years ago.  It's not a fun job to replace the gaskets and I wanted more service life this time around, so I used Yamabond 4 this time and NO paper gaskets.  Yamabond is similar (maybe identical??) to Hondabond and maybe Great Stuff.  It's a gray colored sealant.  I cleaned both surfaces well with brake cleaner to degrease them, then just applied a bead of sealant to the cover pieces. 

I did make one mistake, which was forgetting to clean out the residual solvent (brake cleaner) that had puddled in the bolt holes. It was rather cold in my garage so the solvent didn't evaporate as I though it would and some dribbled out when I tightened the timing case bolts.  This solvent is probably not good to have in contact with the Yamabond.

But despite this mistake it is holding up marvelously and there are no oil drips!!!  I will probably use it when I have to replace the paper oil pan gaskets again.  A bunch of the guys on S14.net have ben using this stuff for a while but this was my first time, as I always thought the BMW factory gaskets would be best. I totally recommend this stuff.

[DesktopDave]

I was planning on trying out Hylomar or Hondabond.  On my bikes, I've had great luck with paper gaskets by greasing them before installing.  I use plain old conventional axle grease.  One odd thing with my bikes is that they require the proper paper gasket.  It shims the case properly...that's critical as the side case is also a bearing surface.  There is no need for that on the BMW as far as I can tell.

I'm told that Threebond (Hondabond, Yamabond, etc.) are a good substitute, and very good at oil resistance.  There is a difference between a gasket maker, a gasket sealer, and a silicone sealant.  I'm also told that cheap RTV liquid gaskets carry an acid base that can discolor aluminum or even erode ferrous metals.  By the smell I'd suspect it's vinegar.  Great for cleaning up rust, not great for long-term contact with warm oil.

[wazzu70]

Yeah its been debated forever the difference between Yamabond, Hondabond ect. Even if they are not the same....they are so similar its hard to tell. Both sealers are anaerobic sealants which means they cure without exposure to air (aka in tight places).

Here is a generic version available at most hardware/auto stores: http://www.permatex.com/products/product-categories/gasketing/anaerobic-gasket-makers-flange-sealants

When the gasket is needed to properly space things out, lots of people prefer gasket shellac to seal the gasket to the surface: http://www.permatex.com/products/product-categories/gasketing/gasket-sealants/permatex--indian-head--gasket-shellac-compound-detail

I think the shellac is what I would use at the timing case just to keep everything spaced properly. Not sure if its necessary or not though.