Crankshaft end play

What is the maximum end play a B engine should have?  Thanks,  Tim

My book says .001-.005 end thrust clearance.

I have pulled the gear off and machined off several thousands off the face to get the clearance right. --- im trying to think back exactly what i did. I know the clearance was about .020 to start with. The gear musth bottom out against the journal and i machined off .015 to push it on further so the original bearing face moved closer in ?  If i had machined the bearing face you would think the clearance would increase.. Been too long ago.

Edited by steve(ill) - 18 Feb 2012 at 3:45pm

I thought one of the main bearings was what was supposed to control crankshaft end play. If the throw out bearing is bad or you spend a lot of time with the clutch pushed in, the thrust bearing gets wore.

Polk diesel in Madison wi  removes gear then remachines crank surface and grinds crank nose the same amount moves crank ahead maybe 15-20 thousands does not seem to hurt   Gary

I have always pressed the gears off and never tried a gear puller. They come of kinda hard. You might be able to use a puller if you heat the gear some while pulling. You can counter bore the gear to get the end play back in spec. Before you do that make sure the crankshaft does not need repaired where the side of the thrust bearing rides on the crankshaft. Other wise you just wast your time on the gear  because the crankshaft will chew up the thrust lip on the insert and you will be back where you started.

Tim, i did exactly what you said. REmove the gear and counter bore so it slide in .015 toward the new bearing. I think i found that some aftermarket thrust bearings are thinner than the original factory unit.

TMiller/NC wrote: CTucker, I think,  the front main bearing controls the movement front to rear, with the crankshaft having a thrust surface behind the bearing and the crankshaft gear on the front side.  I'm thinking if I remove the gear and machine a counter bore in the inside of the gear it would allow the gear to move closer to the front main taking out some of the end motion.  Am I right?????????  Thanks, Tim

Timing change will be miniscule. If you only knew, your endplay was very probably out of spec when you took the engine apart. Counterbore the gear if you want and if you ruin the gear in the removal process you can buy another gear to counterbore. If it was mine, I'd do nothing.

TMiller/NC wrote: Thanks, DickL,  I had the crankshaft main, rod journals ground to .020 under and the person who did the work said he cleaned up the thrust face.   Me being dumb and not understanding the meaning of this,  reassembled the engine and now I find the end motion.  Thanks for the replies,  Tim

The shop that I have grind my crankshafts always take the end play into account when grinding.  Should have been just another dimension in there repair to make on spec.

I am working on a -45 crank right now, .014 end play. I was going to remove the gear, and "manufacture" a steel shim to go between the crank face and the bearing. I had already smoothed the journal face in neighbors lathe. Don't know if it would work or not, never will, because I discovered the mains are .040 under...without the shims

Someone got it right when they mentioned new thrust bearing lips can be several thousands thiner than some of the older ones.  I was lucky to be able to reuse my old front main and eliminate the need for crank machining to move the gear back to narrow the gap to spec for the newer bearing.