S6 5.2 BXA main bearing clearance

A6 All/ S6 All
#1

I am replacing my crankshaft with one from another block so not sure how this will affect which color bearings to use.

The block I am using has “RRRRRR” (all red) stamped on the bottom of the guide frame (bed plate)

The ORIGINAL crankshaft has “GGGGGG” (all yellow) printed on the largest counterweight.

The REPLACEMENT Crankshaft has “GGGGGR” (5 yellow and 1 red) also printed on the largest counterweight.

Should I be going with the color codes for the lower bearing shells from the original crankshaft or the replacement crankshaft? And using red upper bearing shells?

I have all of my main journal and housing and measurements but I cannot find the thickness measurements of new color coded bearing shells anywhere to calculate my clearances.

Does anyone have the thickness measurements of the main bearing shells various color codes? And the main bearing clearances?

#2

I went with blue shells for mine to get the radial clearance right.

I no longer have web access to the Bentley manual, but if you scroll down through the thread linked below, there are a few sections out of the manual that I pasted in when I was selecting my bearing shells.

https://forums.audirevolution.net/t/07-s6-coolant-in-oil-complete-engine-teardown-with-pictures-re-stored/16384

1 Like
#3

Thank you for the info. Great thread by the way, i have referred back to your thread before many times for my build! My journal measurements are not far off from yours (between 64.962 and 64.965) As it was for you, this might be a bit of trial and error process with bearing selection! For reference the repair manual I have been using can be found here: “www.charm.li” (I think this might be the Bentley manual but not sure)