far back as it could go towards the engine i placed the dial
In the case of our big-block Chevy, with its new Number Five thrust bearing, we measured barely 0.002-inch of endplay. about THRUST BEARING FAILURE and how to prevent it.
(this is showing prying in the other direction...but you get the
Most crankshaft bearing sets include a thrust bearing, which sets the amount of endplay.
This bearing will need to be sanded to add the necessary clearance, and get within the specs.
Aside from obvious causes such as dirt contamination and misassembly, there are only three things that generally cause thrust bearing failures. Often, each has blamed the other for the resulting damage. "The problem with polishing cranks manually is that it is totally operator dependent.
If when assembling an engine you discover the clearance to be very tight, there is a simple way to increase the clearance. It’s best to sand only the leading edge side of the thrust bearing when increasing clearance. It damages and … Alternatives may be to try a different bearing manufacturer to see if the clearance will improve although this is unlikely. occurs when the central shaft inside the torque tube expands and Crankshafts are generally among the most abused components in an engine. If nothing else, if crank endplay is not checked and verified, the end result will be disassembling the entire engine to repair the damage, because too loose is just as bad as too tight.
measurements. They provide for a specified amount of crankshaft end play.
We stop and measure every minute or so to check progress. Of course, a thorough cleaning with hot soapy water and a sponge followed by a wipe-down with rubbing alcohol and a white paper towel is necessary to ensure that all of the sanding grit is removed before the bearing is re-inserted into the engine to recheck the clearance. END PLAY & THRUSTBEARING HEALTH. Re: Excessive crankshaft end play Post by 1972ho » Sun Mar 22, 2020 1:10 am Wow Jed what do you mean by move the thrust cap forward are backward its fixed.This a crank that has just been ground and I remember the crank grinder say he needed to kiss it a little.And it is only about .0005-to .001 from Max allowable.
Earl Gillstrom 88 S4 5 Speed Crankshaft end play … If you were lucky enough to take auto shop in high school, you might have been fortunate to be able to “rebuild” one of the class engines.
Measure crankshaft end play with a dial indicator placed against the harmonic balancer or flywheel. It is this clearance we will be addressing in this article. flexplates to some degree and by the THRUST BEARING........BUT
With the lower flywheel housing removed i first
Even if sanding the thrust face is required, the task is not difficult or necessarily time consuming.
For this checking example, we will be using a K1 steel crankshaft in a Dart Little M cast iron small-block Chevy. measurement. With a completely disassembled engine, the first step in this process is to ensure that the proper main bearings are used.
). In the case of our big-block, the endplay came up shy of the minimum spec at barely 0.002-inch.
Align the dial indicator plunger parallel to the crank snout and lightly force the crank backward and zero the dial indicator.
If these grinding marks are not completely removed by polishing, they will wipe the oil film from the surface of the thrust bearing much like multiple windshield wiper blades. Some engine manufacturers have these incorporated into the sides of the main bearing.
), Your email address will not be published. Just like all other engine clearances, the thrust clearance is critical for proper engine performance.
Manual transmission thrust can be excessive with pressure plates that generate high static loads. We used wet/dry 400 grit sandpaper lubed with Marvel Mystery oil. For this story, we’ll be looking at thrust clearance or what is often called end play. Manual transmission cars with the older style three-finger Long or Borg & Beck clutch pressure plate designs, apply increasing pressure as the clutch pedal is pushed to the floor. Thrust bearings are used to control end play in the crankshaft. So for an engine with a range of 0.004 to 0.008-inch, the ideal spec would be 0.006-inch.
We then measure the overall thickness of the thrust bearing end to end using a dial caliper. Engine building isn’t difficult – as long as everything goes according to plan. Using the same areas as before to pry
Now torque the main cap bolts/studs with the oil pump, if so equipped.
We show you how to do the job in this tech segment. We use a 24-inch by 24-inch piece of scrap quarter-inch thick aluminum plate.