3.0 reassembly
 

I am in the process of remating the case halves and have the following question.

I have meticulously cleaned all parts but noticed on a dry fit of the case halves that as I lower the left half the slight dragging of the studs into the opposing case causes aluminum filings to fall onto the mating surface and other critical areas (like the crank journals). It doesn't seem possible to mate the two halves without some stud rub? Do you tilt the lower half as far as possible (without the crank falling out) to allow the filings that may get knocked off to fall to the ground? Or am I worrying about nothing.

Jamie

It sounds like you have a bolt out of alignment. I'm no expert, and I'm sure the experts will chime in, but I would think that you would want to straighten the bolt to make sure it doesn't rub. The case half should slide down without rubbing the threads significantly enough to shave metal.

One thought, experts please chime in, is that you could tape the threads to keep them from rubbing. Use a painters masking tape that is low adhesive so that you can get it off quickly, clean the thread with alcohol, then seal it up.

Just my two cents worth.

When we cleaned up a 3.0 case last weekend we finally applied a generous coat of WD40, put the case halfs together and put the case into a plastic bag. The WD40 is to prevent the studs and the aluminum from corroding while in the plastic bag. After the Castrol Super Clean wash the aluminum had this sandpaper like texture. WD40 gets the surface "used" to oil again.

After that WD40 treatment the two case halves slid together with no problem whatsoever. There was no rubbing of studs. Check your studs with a 90 degree angle to see if they are all straight. While I can't see how one would bend a stud other than dropping the case half you never know.

You do not want any filings to get to the mating surface or the the bearing area. If that happens you are asking for oil leaks, premature bearing wear and/or failure.

Good luck,
Ingo

Sounds like your studs are slightly bent - there should be no real rubbing when they go together.

As for the WD-40 idea, it sounds interesting, but you need to make sure that none of that stuff gets on the mating surface - otherwise it may interfere with the case sealant. I don't recommend pre-filling the oil pump with oil for this sole reason - it's too risky to mess up and get some on the parting line (future oil leak).

-Wayne

We'll wipe down the mating surfaces with alcohol-soaked lint-free cleanwipes right before the case goes together.

I wouldn't rely on "alcohol" to do "degreasing" (or in your case, "de-WD-40ing")--acetone is the better solvent.

I had this problem on my Mg cased motor, turned out I hadn't cleaned the bore holes well enough. Took a rifle bore brush to them and didn't have any problems whatsoever.

Also what's the point of pre-oiling your oil pump? when you add oil the oil drains right down through the S hose to the gears of the pressure side of the pump. It's all in the beauty of a dry sumped motor.