Hey everyone! So I plastigaged the mains on my 4.0 and 1-6 are sitting at .002" and 7 is sitting at.003" is this to tight, or am I just over thinking it?

 

Main Bearing Clearance
0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)

Youll be fine.

 

Thank you very much! And for the spec sheet.

 

You’re not crazy to double-check, but those numbers are generally workable for main TBS bearings on a 4.0—about .002" is right in the sweet spot for most street engines, and .003" on one journal is on the looser side but usually still within acceptable spec as long as the crank journals are round, surfaces are good, and oil pressure will be healthy; what matters more is consistency, proper needle roller bearing crush, correct torque procedure, and confirming with a mic/bore gauge if possible since plastigage can read a little off, but unless the service manual calls for tighter tolerances, that spread alone isn’t an automatic red flag, especially if this isn’t a high-RPM race build.