On 1 Oct 2001 at 16:05, harald_nancy wrote:

> 2.1l main bearing set:
> Just bugged a couple of VW dealers some more, and
> finally found out the whole story.
> It goes like this:
> There were 3 different STANDARD main bearing sets originally
> installed by the VW factory when the engine was built.
> (These are NOT oversized bearings for machining the case or crankshaft.)
> 025198461A  That's the most common bearing installed.
> 025198461A004 (red dot)  It's  1/4000 next larger standard size (smaller
> than blue).
> 025198461A001 (blue dot) It's 1/1000 larger (largest standard size).
> You don't know what bearings you have or combination of bearings until
> you split the case and look for red or blue dots or no dots on your
> crankshaft.
> The first standard size is the smallest. So if you see any dots, blue or
> red,
> you need to get the corresponding larger size bearings. (See Bentley).
>
> In addition to these 3 standard bearings, the VW dealer sells
> oversized bearings (.25 mm and .5 mm) for those engines
> that need to be machined.
>

Having nearly zero first hand experience in this matter (aside from
assisting/watching several marine engine rebuilds 10+ years ago) I
thought I'd mention that the above agrees very closely with an old
diesel engine book I'm currently reading (and actually just read the
section on main bearings last night). Right down to the fact that the
factory often has 2 or 3 "standard" size bearings. It also goes on to
state that middle sizes can be achieved where required by mixing a red
dot upper shell with a blue dot lower shell, for example, in order to
obtain the closest fit.

fwiw...

========================
Shawn Wright
Computer Systems Manager
Shawnigan Lake School
http://www.sls.bc.ca
swright@sls.bc.ca