Crank Dimensions and Bearing Clearances

[Older_not_Wiser]

Been doing a little advance research in preparation for potential engine out repair. The attached is screen grabs from Bentley DVD on crank dimensions and bearing clearance nominal and limits. The red text are my conversions to inches.



My question is about interpreting the Crankshaft dimensions table. Should a new OEM crank main bearing dimension be between 54.00 - .017 = 53.983 mm (2.1253") and 54.00 - .037 = 53.963 mm (2.1245")? If so, I guess I am not used to seeing the tolerance values both be negative.

The only other way I can imagine to interpret this that it is a 3 stage grind/hone with the first hone at 54.00 mm, the second hone at 53.983 mm, and the final hone at 53.963 mm for a final nominal dimension of 53.963 mm (2.1245")?

I am not a machinist so thanks in advance for your help in what the correct interpretation of that table is.

[Older_not_Wiser]

Found this in the B6 A4 section which indicates that the 'New' dimension min and max are both undersized from the nominal.

Repeat, below is for 1.8T Crank.

Crankshaft dimensions

Reconditioning dimension
Crankshaft journal diameter mm - (in.)
Connecting rod journal diameter mm - (in.)

minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
Basic dimension (nominal)
65.00 (2.559)
54.00 (2.126)

minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
1st undersize (nominal)
64.75 (2.549)
53.75 (2.116)

minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
2nd undersize (nominal)
64.50 (2.539)
53.50 (2.106)

minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
3rd undersize (nominal)
64.25 (2.530)
53.25 (2.096)