Main bearing cap torque sequence?

[BigToe]

To ease the installation of a new rear main seal, I cracked the bearing caps loose. I saw a suggestion that there is a proper order in which to tighten and torque the bolts. I googled it but can't seem to find any real info on this mysterious order and figured I check here before I wing it and button this thing up. As always thanks.

 

[Broncobowsher]

Don't recall having a sequence. Each cap is independent of each other. If you go with generic patterns, start in the center and work outward. When building engines, I thing I just started at the front and worked back one cap at a time.

Probably a little more sequence if you have 4-bolt or cross bolted mains. Small block Ford just doesn't care.

 

[Quick & Dirty]

Typically, tighten the rear first to check friction of the oil seal. A new rope seal will take 10-15 ft-lb to turn the crank. A lip seal should be less. Go back and forth between the two bolts to bring them up to spec together. Don't just torque one down then the other.

Do all the other mains except the center. No particular order.

Seat the thrust bearing. With the center cap bolts finger tight, pry the crank forward and back a few times using a large screwdriver between a torqued cap and counterweight, checking for free movement. Pry the crank forward and hold pressure on it while torquing the center cap bolts to spec.

Check end-play, .004"-.008" nominal, .012" maximum.

 

[Ourobos]

Spec is to start with #3, then #2 or #4, then #1 or #5. In 3 steps, up to the specified torque.

 

[blubuckaroo]

Seat the thrust bearing. With the center cap bolts finger tight, pry the crank forward and back a few times using a large screwdriver between a torqued cap and counterweight, checking for free movement. Pry the crank forward and hold pressure on it while torquing the center cap bolts to spec.

Check end-play, .004"-.008" nominal, .012" maximum.

This is a pretty important detail in assembly and is often missed. It makes sure the thrust bearing haves are lined up and in the proper location.