#1 main bearing dowel

[Rupertco]

I am rebuilding a 2L for my bus and had the case checked and the shop said everything was good. I put in the dowel for the #1 main and it is very loose compared to the others. Is this going to be a problem? How do I fix it if I need to? Thanks

[Marc]

The "proper" fix is to use a special stepped dowel pin; the case is drilled oversize to form a true hole.
In fact, the dowel pins are only needed to properly locate the bearings to the case oil passages; when the case halves are mated there's a slight "crush" which holds the bearing in place, it's only at the extreme end of the engine's life (when the bearings and case are severely pounded) that the dowel pin becomes responsible for locating the shell.
Short of the stepped dowel pin, one "fix" is to place a stock pin in the hole and then disrupt the case metal around it with a punch to tighten the fit of the pin - that's best done before align-boring, but it can be done before/without if you're careful to remove any raised metal around the hole.
If the case is seriously damaged to the pont that even an oversize dowel pin won't fix it (or if none is available) an alternate ploy is to drill a new standard-sized hole slightly offset from the original location, and a corresponding hole in the bearing shell. It may be a little trickier to seat the bearing as you mate the case halves, but it's not a big problem.
Judging from the pictures you've provided I don't think you've got much to worry about, I wouldn't lose any sleep over it m'self...but if you're paranoid, take any of the options discussed above.

[doc]

Rupertco,

Welcome to STF!

Marc has certainly outlined the solutions. A little hassle, but most builds have something that goes astray. You are wise to catch it and ask questions now.

At the risk of highjack, I'm interested to know how this may have occurred? The locating pins are usually not too hard to get in and out. The usual mistake is missing the alignment with the bearing on the build up. Is this a wear characteristic? Or has someone previously employed the big hammer?

doc

[Marc]

Most often this is a problem caused by the #1 bearing tearing loose in the case, usually from the crankshaft endplay being set too tight or from too much time spent with the left foot on the clutch pedal accompanied by inadequate oil pressure at idle.

[Rupertco]

Marc,
Thank you for the response. I want to do what is right and not trash all my new components. This case came with the bus when I bought it and I had it checked out by a vw machine shop they said everything is cool. I am hearing different things about what to do. I know this forum is strictly type 4 as apposed to the samba. I am not going for high end just something for a daily driver. I will be running the raby 9550 cam and a stock crank and pistons. The one problem with the case was it had the dreaded GEX label. Somebody also suggest JB weld it in place and call it good. My main concern is just ruining the rest of the components a couple hundred miles in. Thank you for all the help.

[Rupertco]

So with the endplay too tight the crankshaft and flywheel are going to pull that bearing along with as opposed to floating inside it? So with inadequate oil pressure and using the clutch more often you are creating more times at idle and the bearing starts to stick because there is not enough oil? Am I understanding this correctly. Thanks

[Marc]

That sums it up. There's one more "fix" you can do that I failed to mention above, simply use a larger dowel pin after carefully drilling the case hole to size. The hole in the bearing shell is already larger than the stock dowel, so it may not even need to be enlarged. Be sure that the dowel doesn't protrude too far...

[Rupertco]

Thanks for all the info Marc. Somebody on the samba offered me a case for cheap but either way I guess a case is getting shipped to Rimco. I have way to much money invested in this to have it get ruined.

[sideshow]

If you look at the main bearings, you can see how the dowel isn't a press fit on the bearing size. It is used to locate the oiling holes.

What you show doesn't seem bad too me, how did the other side (bearing) look on tear down? I always look at the soft side to see what may of happened.

Standard operating procedure with ANY ENGINE PART STAMPED GEX is bonfire or target. I know people that wouldn't even use GEX touched parts for a wheel chalk. In GEX's defense they don't ruin everything they stamp, it is just a rule of thumb.

[Rupertco]

Thats the problem. I bought the bus with this case as the stand by for the one that blew up so it was empty to begin with. I think im going to send it to Rimco. I would rather spend my money to have it fixed prior to destroying all my new parts.

[dave t]

http://www.thesamba.com/vw/classifieds/ ... id=1138415 . Thanks Dave T

[Rupertco]

Thanks Dave Ill check him out.

[dstar5000]

Speedy's a good guy to do business with.

DOn

[Rupertco]

So How can I check if my bearing journal is not our of round so I can use on of those dowels? Thanks

[dstar5000]

When you put the dowel in, can you wiggle it?
THAT would be a good indicator....

Don