I noticed a lot of crankshaft end play on my 71 340. It supposedly doesn't have many miles on it since a rebuild. The spec is .002 - .007. Mine came in at .033. Attached are pictures of the thrust bearing showing that the crank was thrusting forward and chewing up the side of the thrust bearing.
Does anybody know what could cause this? Could it be that the main bearings were torqued with the crank too far forward and the end play was never checked?
Or is something else seriously wrong?
Without knowing long- term history, impossible to say. Maybe the crank was damaged, and never properly refinished. Did / does the car have a heavy clutch? What is the history of that?
I've seen some of these engines with considerable wear (end play) that ran just fine. This also seems to be true of rod side clearance.
Does the other half look the same on the same side of the bearing web? It's possible the thrust bearings weren't properly aligned before the center cap was torqued?
I know this is a big block but the process should be the same.
http://www.forbbodiesonly.com/moparforum/archive/index.php/t-.html
Does its have screw in studs(ARP)......................if so the main cap has to be inlarged to alow the cap to center.
ask me how i know!!!
To answer a few questions:
The 69 Dart is a 4 speed. I've only had the car for a year so I can't say what happened before that. It had a broken transmission mount (maybe caused by a big block fork instead of the small block fork) and really bad clutch chatter.
The 340 does not have screw in ARP studs.
I will have the thrust surfaces of the crank checked by a machine shop.
Thanks for all the advice.
I had a thrust bearing looking like that,, only it was a little blue in color from heat..
It was a marine engine that had an OMC outdrive on it, Apparently they have two diff length imput shafts for the outdrive,, this one was too long.. Boy did that motor stink, literally..
Perhaps check the 4-speed to see if it's one of those you're supposed to trim the tip off the trans imput shaft, if the crank wasnt drilled for a 4-spd,, Perhaps the shaft wasn't trimmed quite short enuff,, and is shoving the crank forward... just a thought..
hope it helps
I re-read whole thread,, this is a pieced together car,, and I think you need to make sure that crankshaft has been drilled for a manual trans,,.
Could we please see pix of the end of the trans imput shaft,, and the crankshaft flywheel flange with pilot bearing ... ??? thnx
Does your trans go into the crank, like this ?? , here's a similar dicussion
http://www.forabodiesonly.com/mopar/showthread.php?t=
I just got back from vacation. Here are some belated responses to some excellent questions.
The transmission input shaft measures 8 9/16" to the surface that bolts to the bell housing (picture attached).
I don't know if the crankshaft (No. - P4R10) flywheel flange is correct for a 4 speed (picture attached). The far end of the inside of the flange doesn't look rusty, but the end of the input shaft doesn't look worn. It's hard for me to tell if the input shaft is hitting. I can't put the input shaft into the crank flange yet because the short block is on an engine stand, until I take it off to deliver it whole to a machine shop.
I should also mention that I discovered this issue when I pulled the trans to replace the LUK clutch and pressure plate that I installed last summer. The clutch pushed in hard at the top and easy after that, which made it difficult to drive on the street. I put about 1,300 miles on this setup.
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