Assembly on forged lq4
05-21-2013, 07:22 PM
#12
Make sure you seat the thrust bearing in properly for the center cap. The caps will have numbers 1-4 stamped on one side and 5 will be stamped on the other side. Make sure the deck is very clean. I scrape it with a razor blade and hit it with fine sandpaper on a metal block if the engine block is bare. Clean clean clean, and clean some more.
05-22-2013, 12:57 PM
#13
The thrust bearing is the center bearing in an LS engine. The thrust bearing keeps the crank from moving forward or backward. When you tighten down a cap that does not have a locating pin locating it to the proper place on the block it will not be lined up properly. You could check this by installing the center bearing and cap without the crank in the block. When you tighten it down, place a flat straight edge on the thrust bearing area, and you will see that it is not flat unless you got lucky. Here is how I do it, and other may choose a different method. install the center cap, and tighten it down to set the cap flat to the block. Loosen the bolts, and install them finger tight. I use a plastic dead blow hammer, and tap the crank forward and backward. If you notice on the crank there is a machined area on the throw before and after the center journal. That is where the thrust rides. Moving the crank forward and backward will force the bearing to be centered so it can be torqued down. It is easiest if you can have a friend pry the crank backwards while you torque it properly. Torque it down and check the thrust clearance with a dial indicator to make sure it is within spec. The thrust clearance is checked with the bearing dry. Assemble it finally with lube.
