crank wont spin...zero endplay
crank wont spin...zero endplay i started putting together my motor tonight, and after checking everything with a plastiguage, then torquing the main caps, the crank wouldnt spin. took it all apart. everything seemed aok, tried it again, and it still wouldnt spin. Im pretty sure the problem roots from the thrust bearing (#3) any suggestions
specs:
LS2 block std.
Stock GM crank turned 10 with matched clevite 77 bearings
ARP 12 pt main studs
GM bearing caps
BTW this is my first shortblock
TIA
specs:
LS2 block std.
Stock GM crank turned 10 with matched clevite 77 bearings
ARP 12 pt main studs
GM bearing caps
BTW this is my first shortblock
TIA
Are you sure you have the main caps on the right way? If you think its the thrust, take all the main caps off, except for the thrust, torque it to 18 ft pounds (no need to torque it to specs at this point) and see if the crank spins.
I would bet you have one or more caps on backwards. They can go on either way.
I would bet you have one or more caps on backwards. They can go on either way.
Also take a look at the crank journals, (main and rod) to see if the crank grinder went all the way out to the edge of the counter weight. If he left a gross radius at the edge, your bearing may be touching in the corner not allowing the crank to spin.
D.J.
D.J.
What kind of clearance do you have on that center bearing using your plastiguage? Or that thrust is kicking your butt. If you have some Dyekem layout dye paint it on the thrust surface. Install the cap and just snug it down. Rotate the crank then remove the cap. Look at the Dyekem to see if it's hitting on both sides, (front and rear). It should give you an idea of where the problem is. If you don't have Dyekem use a Magic Marker. The only other thing I can think of is the crank is bent or the crank grinder F'ed it up some how.
D.J.
D.J.
Last edited by OneQuickCoupe; Dec 1, 2007 at 04:29 PM.
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when my engine was put together it had the same problem
it was the Thrust bearing
the main cap needs to have a small angle ground onto the corners
if you look at the bearing it has a 45 degree angle on the inside corners
it was the Thrust bearing
the main cap needs to have a small angle ground onto the corners
if you look at the bearing it has a 45 degree angle on the inside corners
the caps are in the correct direction. all other bearings are fine. it's the thrust bearing. we'll check for the angle and for a contact patch. it's not bearing diameter, plastigauge checks out fine at .015.
the journals all seem ok, and the caps are all in the correct direction. i have been told by two people to sand the bearing down using sand paper on a piece of flat glass. any have experience with this?
If you think its just the thrust bearing, install the rest of the caps and torque to 18 ft lbs and see if it spins.
Then if thats good, take the crank back out and see if the thrust bearing fits in the crank with the crank and bearing out of the block.
Then if thats good, take the crank back out and see if the thrust bearing fits in the crank with the crank and bearing out of the block.
Did you seat the thrust before torquing it down? How much endplay do you have? Factory is .0015-.002, but you can have as much as .005-.007 If there's a problem with the radius on the main journal you will probably have none at all.
