Crankshaft thrust washer characteristics?
Anyone have a crankshaft thrust bearing/washer go out? What characteristics did the engine assume?. Noises?

 

I was driving a S-10 V-6 once that I borrowed from my dad. Was driving along and all of a sudden it started making the worst scraping noise I'd ever heard in my life. Before I could find somewhere to pull over it flung one of the belts off. I put the belt back on and when I started it up the noise was gone. Had the guy with me to step on the gas as I observed. The crankshaft was moving foward everytime he stepped on the pedal causing the flexplate to scrape against the back of the block. If he revved the engine real fast it would throw the belt off.

 

Will do the rev engine test. Sounds like a possibility based on the noise you mention. But it is not continual. No belts being flung off so far. We started with a 2000 automatic engine, added a 2004 6 speed while still using 1999 5 speed flywheel. I dont' think the parts crossover is the problem though.

 

Put a dial indicator on the damper, and push and pull the crankshaft back and forth by wedging a bar under the damper, and under the flywheel. Check the spec.

Do you have a scraping noise anywhere? Belts coming off? (that would take a LOT of slop to happen).

Is it the engine separator plate vibrating? The V10 likes to rattle that plate without a bellhousing inspection cover pushing it forward enough to keep it from rattling (bellhousing cover rattle on the automatics makes a rasping sort of sound).

 

I did a rev engine observation, but could see no crankshaft movement. The mechanic says there looks to be about .050 using the prybar. That's about a spk plug gap. But we didnt' spec it.

Had a scraping and grating noise intermittently before the recent clutch change, most often after sitting in traffic or in city redlights for 10-20 min. Could be a shiled heating up.

After a clutch change, had the grating sound in day 2, followed by a noisless day, then in day 4 another noisy day. For about 2 wks after that, relatively quiet.

I dont' espect it to be over, but it seems livable and I don't think it will leave me sit due to this noise. When we pulled the clutch, the mechanic said he saw no shavings or scrapings on the back of the engine block.

Most of the heat sheilds are already broken off of he y pipe and it is a rpm related sound. The other thing we considered would be if there was a baffle inside the oil pan that was loos and scrapng against something on the crank.
But it sounds very much like something scratching against a heat sheild.

Thanks for the thoughts. Will intend to post if it gets worse or if I decipher the problem.

 

From my 2001 service manual:

Crankshaft End Play 0.075-0.377

I'm going to assume that's mm's because everything else is, so that's .0029-.014"

.050" is way over.

You start getting into piston pin side-loading and other things when it gets that high.

If you plan on keeping this motor for any length of time, I'd definitely pull the pan and check/change the thrust washers. There are two on top, and one on the bottom, surrounding the rear-most crank bearing.

On the other hand, you could just keep going like it is - but that noise, without any visible contact from the flywheel-to-the-block, might be something bad - like the timing chain gear contacting the timing cover...

 

Well, definately worth specking. So the process would not be an engine out deal? It is a 4X4. Maybe next time it does it, I'll take a vaccum hose from the ear to different parts of the engine and driveline and see if I can isolate where it is coming from. Timing chain gear contacting timing cover... ouch.

If I remember correctly, you've rebuilt one or more of the v10's. The thrust washers can be accessed from the pan?

The engine is worth keeping going. It uses a qt between 3k and then again between 3k and 5k. Very acceptable. I should check mechanical oil pressure also. If there is sideplay on the crank or piston pin, it could be dropping oil pressure without me realizing it due to the binary properties of the static oil pressure switch. (how's that for modernizing technical jargon?)

I suppose it's something I should really look at. Never threw a belt yet and it doesnt' look as though it's been close to being thrown.

I think that spec has to be mm. .37 would be 3/8 of an inch. On the other hand, .014 inches is very little allowance. We're talking feeler guage stuff.

 

I've never rebuilt one - one guy I think did, or at least, took one or two apart, but never reported back. Most that replace the motor get another used one, or a complete new crate motor.

Most engines I've ever worked on had about .010" max endplay. .004-.010 is about what most Ford V8 engines had.

The thrust washer on the rear main bearings in the V10 should be accessible, I haven't delved into the service manual enough to check that. But, here's the text from the '01 service manual when installing the crankshaft - sounds like they should be replaceable when the pan is off, but the engine is still in the vehicle.

The trick is, are the washers worn, or is the crank shot?

Dunno at this point what you'd want to do, but at least you'd find out what the problem is.

Also, don't know if you could find oversize washers.

A brand-new crank is only $356 from a Ford sponsor here FTE/PARTS-GUY.

Can't find any thrust washers.

Sealed power does make a .005" oversize thrust washer, which using all three, would only get you .010" less than what you have now - I'd really REALLY get a real measurement before you take it apart. Found the Sealed Power part # 4507F at rockauto.com (another sponsor).

Maybe if the crank is a little worn, and the thrust washers are a little worn, the .005" oversize washers might get you back into spec...

Assuming the crank is usable and not badly scored...

Lots and lots of work... Matter of fact, my 4x4 '01 has a big cross-member under the engine... But does have a lot of access to the rear of the engine.

Hmm...