Crank end play
Crank end play Hey guys I recently put an ls1 long block together with forged rods pistons and used crank(checked by machine shop) and overlooked checking the crank end play. Now I want to go back and check it, does anything need to be removed in order to check it? Right now it's a complete long block with all the front accessories bolted on. I ask because right now I cannot budge the crank and a .002 feeler gauge will not fit between the thrust bearing. And I've already ordered a dial indicator setup to check.
Thanks
Thanks
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
If you can't move your crank .004 with a prybar you have a problem. Disassemble and figure it out. I check mine in the car with the belts off the front of the crank pulley. Nothing else needs to be removed.
You need to have engine oil pan, windage tray and pickup off in order to check the endplay, also need a dial gauge to make it easier than using feeler gauges...at least you figured it out no before you had issues
Loosen the main caps and side bolts, smack the crank front and rear a few times with a heavy plastic mallet (or a regular hammer with a block of aluminum) to seat the thrust bearing. If you have sufficient clearance, torque the mains back down...
I just setup the dial indicator and got a consistent .0015" sometimes .002", so there is something.
Right now no I cannot turn it by hand but it does turn smoothly with a ratchet, I dont know if the pistons being in are making it harder?
what is the next step to increase the clearance? Does anything else need to be done/checked before sanding the thrust bearing?
thanks
Right now no I cannot turn it by hand but it does turn smoothly with a ratchet, I dont know if the pistons being in are making it harder?
what is the next step to increase the clearance? Does anything else need to be done/checked before sanding the thrust bearing?
thanks
I did do this to seat the thrust when i assembled the engine. If i end up taking the thrust bearing out to sand it down a little I need to do this each time the caps are torqued down correct?
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Try this. Remove the thrust bearing completely, torque the remaining 4 caps and see if it turns over by hand. If it does, you can shave the thrust bearing as mentioned. If not, you've got other problems...
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Verdad Gallardo Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
No you don't, stop giving advice. The correct method for aligning the thrust bearings is a prybar with solid tension while you finish the main cap tightening, not wham back and forth with a rubber mallet.
.002-.003 is pretty common for stock engines.
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
.002-.003 is pretty common for stock engines.
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
.002-.003 is pretty common for stock engines.
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
I would loosen the center cap only.
Pry the crank back and forth using another main cap that is tight.
Tighten the inner bolts to the 15ft lbs while pulling forward on the crank.
Check end play.
Loosen the center bolts again.
Pry the crank backward and pull the center bolts to 15ft lbs.
Check end play.
Tighten the crank bolts pulling the crank whichever way gave you the higher number.
If the number is between .002-.003 I believe it will work. I have built a few using this system and they have worked well.
Kurt
If I end up needing to take a little material off of the thrust bearing what grit sand paper should be used? And material should be taken off both sides as evenly as possible correct?
Last edited by danyboy1409; Jul 17, 2013 at 11:24 PM.
You guys are overlooking something important.....if it was pre-oiled, that could be taking up .001 - .002 by itself.
The end-play figure of say .004 is a DRY measurement meant to leave room for precisely the film of oil I'm speculating may be causing the end-play to look less than it actually is.
However, If you pry the crank alot and have zero end-play (playing devils advocate here), it could show .001 - .002 just from the flex from the torque of the pry bar. Hopefully just a gentle persuasion moves the crank fore and aft the .001 - .001 the OP is seeing now.
Assuming thats the case and the surface was hopefully pre-oiled, the OP might have just what he needs without addressing anything but its hard to tell without trying to get in there and dry things off....not easily done with an assembled shortblock.
My gut says he has enough if a gentle persuasion is moving the crank .001 - .002 now cause for sure the film of oil trapped there is a minimum of a thou leaving him with close to .003 or better.
This is the kind of **** you lose sleep over though which just sucks....
-Tony
The end-play figure of say .004 is a DRY measurement meant to leave room for precisely the film of oil I'm speculating may be causing the end-play to look less than it actually is.
However, If you pry the crank alot and have zero end-play (playing devils advocate here), it could show .001 - .002 just from the flex from the torque of the pry bar. Hopefully just a gentle persuasion moves the crank fore and aft the .001 - .001 the OP is seeing now.
Assuming thats the case and the surface was hopefully pre-oiled, the OP might have just what he needs without addressing anything but its hard to tell without trying to get in there and dry things off....not easily done with an assembled shortblock.
My gut says he has enough if a gentle persuasion is moving the crank .001 - .002 now cause for sure the film of oil trapped there is a minimum of a thou leaving him with close to .003 or better.
This is the kind of **** you lose sleep over though which just sucks....
-Tony
You guys are overlooking something important.....if it was pre-oiled, that could be taking up .001 - .002 by itself.
The end-play figure of say .004 is a DRY measurement meant to leave room for precisely the film of oil I'm speculating may be causing the end-play to look less than it actually is.
However, If you pry the crank alot and have zero end-play (playing devils advocate here), it could show .001 - .002 just from the flex from the torque of the pry bar. Hopefully just a gentle persuasion moves the crank fore and aft the .001 - .001 the OP is seeing now.
Assuming thats the case and the surface was hopefully pre-oiled, the OP might have just what he needs without addressing anything but its hard to tell without trying to get in there and dry things off....not easily done with an assembled shortblock.
My gut says he has enough if a gentle persuasion is moving the crank .001 - .002 now cause for sure the film of oil trapped there is a minimum of a thou leaving him with close to .003 or better.
This is the kind of **** you lose sleep over though which just sucks....
-Tony
The end-play figure of say .004 is a DRY measurement meant to leave room for precisely the film of oil I'm speculating may be causing the end-play to look less than it actually is.
However, If you pry the crank alot and have zero end-play (playing devils advocate here), it could show .001 - .002 just from the flex from the torque of the pry bar. Hopefully just a gentle persuasion moves the crank fore and aft the .001 - .001 the OP is seeing now.
Assuming thats the case and the surface was hopefully pre-oiled, the OP might have just what he needs without addressing anything but its hard to tell without trying to get in there and dry things off....not easily done with an assembled shortblock.
My gut says he has enough if a gentle persuasion is moving the crank .001 - .002 now cause for sure the film of oil trapped there is a minimum of a thou leaving him with close to .003 or better.
This is the kind of **** you lose sleep over though which just sucks....
-Tony
Thanks Tony, When I was prying the crank back and forth it was a using consistent pressure but being the first engine we have assembled I have nothing to compare the amount of pressure that I applied. That being said if I want to check the DRY end play do all of the mains need to be wiped clean of the assembly lube (PERMATEX red ultra slick) or does only the thrust bearings?
I definitely cannot afford to rebuild this motor as I am a college student so a little peace of mind would be nice. If that means it needs to be taken down to the crank then I will. Ill first do what "427" recommended to see if i can get something a little better than .0015 by seating the thrust bearing while gently forcing the crank forward or backward, and take extra notice on how much force I'm putting. If it still doesn't put me at ease than a dry measurement will be made.
Thanks again
Only the thrust needs to be dry.....if you can snake the upper thrust bearing out and dry it off (the lower one in the cap is easily accessible), then you can check the thrust the proper way (dry).
Good luck with that
-Tony
Good luck with that
-Tony
Thanks Tony, When I was prying the crank back and forth it was a using consistent pressure but being the first engine we have assembled I have nothing to compare the amount of pressure that I applied. That being said if I want to check the DRY end play do all of the mains need to be wiped clean of the assembly lube (PERMATEX red ultra slick) or does only the thrust bearings?
I definitely cannot afford to rebuild this motor as I am a college student so a little peace of mind would be nice. If that means it needs to be taken down to the crank then I will. Ill first do what "427" recommended to see if i can get something a little better than .0015 by seating the thrust bearing while gently forcing the crank forward or backward, and take extra notice on how much force I'm putting. If it still doesn't put me at ease than a dry measurement will be made.
Thanks again
I definitely cannot afford to rebuild this motor as I am a college student so a little peace of mind would be nice. If that means it needs to be taken down to the crank then I will. Ill first do what "427" recommended to see if i can get something a little better than .0015 by seating the thrust bearing while gently forcing the crank forward or backward, and take extra notice on how much force I'm putting. If it still doesn't put me at ease than a dry measurement will be made.
Thanks again
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I'm no engine builder but I can speak from experience. When I checked mine, installed in the car, no acc belts, the crank was in the rearward position. I gently pried forward between the front cover and balancer and there was a distinct thud/thud as I applied then released pressure. Exactly .004 wet. This was a low mileage shortblock as assembled from GM.
I always put thrust @ .005"-.007" dry...27 yrs. assembling engines; 1000+
built.....As Tony stated the assembly lube being used can greatly influence
the measurement. I prefer using white lithium grease or thin motor oil for
bearing protection during assembly as the red goey cam lube **** is just so
thick that it affects how the engine turns over when building it....Makes you
think somethimg is too tight or binding even though you've measured the
clearances and know them to be fine.
built.....As Tony stated the assembly lube being used can greatly influence
the measurement. I prefer using white lithium grease or thin motor oil for
bearing protection during assembly as the red goey cam lube **** is just so
thick that it affects how the engine turns over when building it....Makes you
think somethimg is too tight or binding even though you've measured the
clearances and know them to be fine.
I always put thrust @ .005"-.007" dry...27 yrs. assembling engines; 1000+
built.....As Tony stated the assembly lube being used can greatly influence
the measurement. I prefer using white lithium grease or thin motor oil for
bearing protection during assembly as the red goey cam lube **** is just so
thick that it affects how the engine turns over when building it....Makes you
think somethimg is too tight or binding even though you've measured the
clearances and know them to be fine.
built.....As Tony stated the assembly lube being used can greatly influence
the measurement. I prefer using white lithium grease or thin motor oil for
bearing protection during assembly as the red goey cam lube **** is just so
thick that it affects how the engine turns over when building it....Makes you
think somethimg is too tight or binding even though you've measured the
clearances and know them to be fine.
But I hear you.....it could cover up a small problem that might not have gone as easily overlooked. In fact I always check the crank with regular motor oil first as a confirmation it spins perfectly after all my clearances are dialed in and accounted for.....then I wipe it clean and use the sticky red assembly lube which really stays attached to the crank journal and bearings offering the break in protection its ideal for.
-Tony
