I'm assembling a 440 and after installing and torquing the main caps I have practically 0 thrust when measuring at crank snout. I used Driven assembly lube on journals and bearings with oil on backside of the bearings and the main saddles and caps, could this cause tighter measurements? Should I have measured this dry and clean? If I pry the crank forward or aft the dial indicator returns to the original number, wondering if I am doing something wrong. The crank was turned 10/10 and the block was align honed and zero decked by one of the more reputable machine shops in my area so I feel confident in the work they performed.
Crankshaft end play tight?
- Thread starter Boris7K
- Start date
Was endplay checked with only #3 bearing installed and torqued?
I always take a large dead blow hammer and drive on each end of the crank to help seat in into the mains. Thrust bearing needs to get seated. Sometimes just loosen the bearings and seat the crank and retork and seat it again.
All caps and bearings installed.
I'll try that.
Right, I am not sure how long this will sit before I am able to start it so I figured a little oil will keep any rust at bay.
Agreed, the backs should be clean and dry for friction grip to the block
I'll pull them and clean that up then, maybe try checking the thrust clean without assembly lube.
Back off of the torque on the thrust cap and just run the bolts up hand snug. Then hit each end
of the crank back and forth a couple of times to move the thrust faces so they're lined up. You want
both faces in line. Then torque the cap down and check your crank end play with a dial indicator. Should
be 0.005 to 0.010. If you have a manual trans, this is very important because that thrust takes all of the force
of the clutch throwout bearing. If not lined up right, you could wipe it.
of the crank back and forth a couple of times to move the thrust faces so they're lined up. You want
both faces in line. Then torque the cap down and check your crank end play with a dial indicator. Should
be 0.005 to 0.010. If you have a manual trans, this is very important because that thrust takes all of the force
of the clutch throwout bearing. If not lined up right, you could wipe it.
After removing and cleaning everything, I put the uppers bearings and crankshaft in it, installed #3 main cap and torqued it to 110 lb/ft (ARP studs), thrust measures at 0.004. Will that work with an auto trans? FSM calls for .002-.007 with .010 being max tolerance. I'm inclined to lube it up and move on.
Did you align it like zxzzyx said? I would be ok with .004
4 thou is good. I'd rather be there than 10 thou on a new build.
0.004 i O.K., but you need to slap that crank around to get the two halves aligned!
I'll bet if you do that you'll come up with something aroun 0.007.
I'll bet if you do that you'll come up with something aroun 0.007.
Lefty71
Well-Known Member
If you are going to pull it apart, it should be simple enough to just take the bearing and the crank and get a base measurement with feeler gauges. I know it's not correct, but you should get a pretty close guess there. Anything less once its reassembled and I'd be looking for problems with the other mains, like make sure you are'nt tight into a radius maybe (wrong bearings for your crank), or some other interference. Is the rear seal assembled??
Rebelrouser
Well-Known Member
If you decide you want a little more clearance, I use some 400-grit wet dry sandpaper and on a flat surface use some thin oil and sand the trust surface of the bearings, you can get a couple thousands that way very easy.
You didn't mention the intended use or power level...it is within factory spec so okay for a factory-type rebuild. If it's a modified mill and you plan on funnin' with it (and this is "just me") I'd wanna see it just a tad looser.
Didn't think about bearing half alignment, I'll loosen up the cap and see if I can get any more. As far as the build, it should do a little better than stock but less than 600 HP.
After loosening the #3 cap and smacking the crank back and forth, then torquing #3 I gained 0.001, so only a touch over .005. I think I'm moving on, thanks for all the replies, truly appreciate the help around here!
Geoff 2
Well-Known Member
0.004" is good, more than enough IMO. Too much play & it allows the crank to 'hammer' the brg.
All the parts concerned are steel or c/iron which have the same expansion rate. So it will be 0.004" hot, cold & in between...
All the parts concerned are steel or c/iron which have the same expansion rate. So it will be 0.004" hot, cold & in between...
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