[brut67]

I was installing new main bearings today .25mm oversize and I could not get the crank to rotate freely. I double and triple checked the main cap positions and orintations. I mic'd the crank, installed the bearings without the crank and mic'd the bore...all seems good. Any suggestions?:idea:

 

[4bt Terra]

What are your clearances?I just put mine together,all went well with .25mm
Sergio..

 

[BobS]

Did you check your clearance clean and dry using "Plasti-gage" :idea:

 

[brut67]

Well so much for relying on my digital micrometer....Per Bob S. suggestion, I checked the clearance with Plasti-gage. The result is I have clearances from .001" to .002" and it's back to the machine shop to turn the crank a little. Thanks Bob S.

 

[WC53]

What clearance does Cummins call for ?

i usualy do one cap at a time and rotate the crank once to see if anything is out of wack . I once had a thrust bearing that would sit high . It turned out the block had not had a radius machined at the favctory . We radiused the block with a grinder and were good to go . Hard to explain but it worked like a charm .

Bruce.