Jim85IROC

iTrader: (6)

When I did my pre-assembly, with everything lubricated with SAE 30 motor oil, I established a crank endplay of .004". I did my final assembly last night, including a good slathering of Permatex assembly lube on the bearings and journals. I followed the proper installation procedure for the crank, including a few good whacks to the crank forward and back with the inner main bolts torqued to 15ft-lbs. The crank rotates freely (as freely as one could expect when sitting in peanut butter), but I don't have my .004" endplay anymore. If I reef on a screwdriver between the main cap and the counterweight, I can squeeze out about .002". Is this just the thickness of the assembly lube preventing me from getting my .004" measurement?

Always2Slow

iTrader: (8)

When you took your first measurement where all the same procedures followed with the same torque values? It is possible that you might have not a good seating of the thrust bearing

Jim85IROC

iTrader: (6)

Yes, all of the torque values & sequences were followed both times, and in both cases, the crank was smacked forward and back after tightening to 15ft/lbs but before final twist. The crank rotates nicely, though obviously not as easily as it did with the SAE 30 instead of the assembly lube.

Hanzy98LS1

iTrader: (6)

I would pull it and try again but smooth out the loob with your finger make shure its uniform.

1fastlsx

what should your end play be?

Jim85IROC

iTrader: (6)

Yes, the torque values & sequence were exactly the same both times, and in both cases, I smacked the crank forward & back at the same point in the sequence.

speedtigger

iTrader: (16)

To answer your question, yes the viscous assembly lube will affect your measurements. It could easily be responsible for the measured difference.

Jim85IROC

iTrader: (6)

Thanks.

Neil B

iTrader: (1)

I just went through this on my Gen 1 SBC build. I had .007 endplay during pre-assembly and .0045-.005 endplay on final assembly. I loosened the caps and gave the crank a few more good smacks. I checked endplay again before tightening the caps and got close to .007 again. I then torqued the caps in 3 steps, checking endplay after each step. My endplay ended up around .0055-.006 after final torque. Might be something worth trying for peace of mind.

Jim85IROC

iTrader: (6)

Thanks. As much of a pain as it is, I'll have to loosen things back up and go through it again for the piece of mind.

speedtigger

iTrader: (16)

On the older engines, we would leave the main bearing cap loose that contained the thrust bearing, tap the crank shaft with a rubber mallot on both ends to "center up" the bearing cap before we tightened it down. This would make sure the cap was true to the crankshaft thrust bearing surface and assure maximum end play. I have never assembled a LSX short block, so I don't know if they have centering pins or bushings on the thrust bearing main-cap. I don't know if this is helpful or not.

Tony Mamo @ AFR

iTrader: (13)

You will have less endplay with assembly lube for sure.....the oil is displacing some of the clearance.

BUT....if your unsure and just want to sleep better at night I would advise you check and make sure you have the .004 you had originally. A mistake is costly.....rechecking your work is free!

Good luck with the build....

-Tony