noticed today pulling the tranny and clutch to change the rear main seal, that my crank moves about 1/16" forward and back (maybe a little less but it's close to that measurement), i never noticed this much play on any other LSX vehicle I've worked on, anybody have any ideas ? ..thanx

 

surely someone has some input...

 

i hear you want a min/max of somewhere around .006"

 

i believe that is for a new build, there has to be a wear limit somewhere...or for someone to ease my mind a little....thanx

 

its only going to get worse. i dont know an exact measurement but the bearing isnt too thick... (guessing) an eighth inch or so? i could get an exact measurement tomorrow, but either way, its not good. dont get me wrong i wouldnt panic or anything but definitely, schedule it.

but what do i know......?


EDIT: no, i believe i would panic... ive seen thrust bearings wear out. not an LS thrust but ive seen what it can do to a crankshaft.

 

thrust wall runout is .001 in.
crankshaft endplay is .0015 to .0078 in.

 

well that sux..thanx for the help

 

put an indicator on for S&G's, got .035-.037...so i guess i'm screwed...

 

ya...as long as your reading it right

 

Do a search for a history of this problem before you jump to conclusions. A service manual may be able give thrust measurement on a non new motor. On my 427 build, I ended up with a max thrust of .0035".

 

i have considerably more play than you did...

 

that came right from gm specs

 

I had the same problem on a SBC. The Oil pump P/U tube fell off during a race. Pressure dropped and I shut it down immidiately. I replaced the P/U tube but a few months later I started hearing a knock that I couldn't find. Come to find out the counter weights on the crank were making contact with the block. Goodby crank.

 

that aint helpin me any.....

 

my phone doesnt take real good pictures but this ACL bearing is right at .090

 

so if the thrust surface is .090, acceptable limits from GM of .0015-.0078, assuming middle of the road at .0063, i'm about .028-.030 into the bearing....nice...what are the chances of milkin this for a year or so ?

 

i meant piece of mind HEMIETR, not info, i appreciate your input....

 

did you check your endplay?

 

id say very good... in bizarro world. who knows, you might get lucky... i wouldnt let it go any further. how many miles on it?

 

.035-.037, posted above