Garbage in Oil

[Thumperbird]

Ok so first up is lots of crank end play, have not gotten engine out yet but guessing it is between .05 andd .1.
I know torque convertor had lots of forward and back shaft play before I bolted it up so I don't suspect an issue there but will check as I disconnect trans before pulling motor.  If lots of play then ballooning wouldn't be an issue correct?

What I am wondering is what else could cause thrust bearing wear?  Want to keep my eyes peeled as I disassemble and not miss something.  My biggest fear here is getting the thing all tore down and not knowing WHY this or that happened.

I also have a worn brass gear on the distributor, gotta refresh myself on that, I intentionally installed it after doing what I thought was proper homework at the time but recent reading suggests it should not have been brass.  MSD distributor on a Lykins custom cam.

More to come but any thoughts on causes for serious thrust bearing wear other than trans/convertor related?
That may still be it but just curious what to look for as I go here.

Thanks

[Rory428]

Just curious if you have a factory Ford crankshaft. I have never had a thrust issue with an OE crank, but I know a few guys who have had offshore aftermarket cranks eat up the thrust bearings, most likely do to poor machining.

[Thumperbird]

Scat cast I think was not super spendy.  This is a 445 with H beam rods, Federal Mogul bearings.

[1968galaxie]

A poorly machined thrust surface on the crank is certainly a possibility.
It will be interesting to look at.

[blykins]

How long are your flexplate/flywheel bolts? 

Usually when I hear of guys with thrust bearing issues, it's either a converter issue, clutch issue, or the flywheel/flexplate bolts were too long.  I've seen many a block come in with a grooved rear cap. 

I have not had any thrust surface issues with Scat cranks.

You need a steel distributor gear.   Bronze gears are junk if you plan to put any miles on them.

[Thumperbird]

I know I was aware of flywheel bolt length when I assembled, can't get eyes on that until I seperate trans..
(only motor is coming out at this point and have not gotten there yet)

I did try and measure torque convertor clearance, rough estimate is .160" of convertor travel before it bottoms out in trans when crank is pulled all the way forward and .1" of travel when crank is all the way back, this is indicaiting roughly a 60/70 thou. crank runout, hard to get a great # while in car.  Of course no way to know which side is worn yet so not sure what nominal crank posiiton is wrt the convertor clearance.

In the worst case crank all the way back scenario is that .1" enough torque convertor clearance?  I am guessing I do run a lot of trans pressure, harding shifting C6 from Broader, have made probably 50 to 75 informal 1/8 miles with it, redlinging at ~5600 to 6000 rpm.

For now, is there anything else I can/should observe/measure before I seperate motor from trans?
Maybe I'll try and lift motor just enough to get pan off while still in vehicle so I can get a bottom side view.

Thanks.

[Falcon67]

Nominally you should want about 1/8" movement between the converter and the flex plate.  If the crank is moving - yea, you've got a thrust issue.  The spec is usually .008 so any real movement in the crank is not good.  I've had a stock 351C crank do that but I suspect it was some sort of debris that go into the thrust area.  The crank was modified for neutral balance and we might have missed something on the thrust surface caused by welding in heavy metal slugs.  At any rate, it "machined" a solid groove in the crank thrust surface and allowed better than .100 crank end play.  I found out because it got bad enough to slow the engine on launch - the crank counterweights were rubbing the block bulkheads.  Other than that, the engine ran fine LOL.  I still have the crank, mostly because it's got probably $400 in metal still in it.

The only other time I've seem a sliver of metal like that is when some valve spring shims got eaten up.  Apparently had some non-hardened shims that got in my spares and they don't last long under a working performance spring.  Lots of little strips of metal in the pan. Like to never figured out what was going on since most of the bad shims had already been shredded.

[Keith Stevens]

The Minimum crank thrust play on an FE is .010.

[blykins]

The Minimum crank thrust play on an FE is .010.

I would not consider that to be the minimum, more like the maximum.   .010" is at the very top end of what I would like to see on crank thrust.   I generally like to see about .005" when I check it.

[Thumperbird]

The fun begins.  Pictures will tell most of the story but still need some help on root cause.
Trans side of main thrust bearing is toast, worn into what I suspect is a steel backing material.
This looks to be the source of that shaved off piece of steel, see image for similar piece of flash still stuck to bearing.
Unfortunately there is a deep groove worn into that side of crank thrust surface.  Is this crank toast?
No evidence of flywheel bolts touching back side of engine but torque converter to flywheel interface may be where my problem lies.  It looks like flywheel bolt heads bottomed out on center part of converter so there was no contact between flywheel and converter on the raised ring or at the outer ears of converter.  This is where I need the collective experience here to guide me.  I feel like the center of the converter is most prone to ballooning and expansion so since I did not have any clearance there even thoough I had overall converter movement/clearance installed, say .1"  that is not enough in this condition?  Wondering if I was not supposed to use the doubler ring when installing afttermarket flywheel?  The doubler thickness is surely enough to have caused flywheel bolt heads to protrude enough on converter side to bottom out in center before perimeter was seated.  Have not check all bearings yet, obviously the motor had trash in it, what I can see of cylinder walls looks good so far, main bearing of course shows some wear as that is where teh concentration of debris would have been, more to come on that front.  What do you all think?

[Thumperbird]

More images

[Rory428]

Maybe I am seeing it wrong, but it kinda looks like the flexplate reinforcing ring is installed between the crankshaft and flexplate, is that correct? It should be on the transmission side of the flexplate, as a spreader, and not a spacer. The flexplate to crank bolt heads were certainly making contact with the convertor, which would cause the damage. Is it a factory flexplate?

[Thumperbird]

Ring is on trans side, you are looking at flywheel and ring from trans side so not a spacer between crank and flywheel, just a doubler but that doubling pushes bolts farther back and they contact center of converter.  The indent if you will in flex plate is towards trans as well which I think is proper.  Aftermarket flex plate, do not recall manuf..

Fyi, this is a C6 in a 65, 65's normally had green dot trans, 66 tbirds did have c6 though, so new trans, converter, and flex plate combination tied to scat crank.

If converter is bolted hard to flywheel anyways, just makes contact in different area, looking to understand dynamics of the failure, this setup was just worse case for being able to handle any balloning or something else or ?

Is this where a flex plate gets its name? converter pushes on outer diameter of plate, plate absorbs some of that by deflecting and less load on crank then or ?

Sorry for miilion questions, trying to learn and not make same mistake twice.

Thanks.

[jayb]

Since the trans side of the thrust bearing is worn, something is pushing the crankshaft forward.  I think you have a converter problem.   I've had had at least a half dozen converters that required spacers on the bolts or studs between the flexplate and the converter, in order to have the converter clear properly.  You install the converter, check to see that it has endplay, then put in the bolts and when you tighten them, it draws the flexplate up to the converter, basically bending it all the way around so that it bolts all the way on.  The trick is to make sure that before the bolts are installed, the converter can be pushed all the way to the flexplate, so that there is no gap between the converter and the flexplate at the mounting bolt locations.  If you see any little gap there, spacers around the converter bolts are going to be required.

To be honest I'm not sure how that would result in forward pressure on the crank, but it certainly isn't right.  The witness marks of the crank bolts on the converter pretty much tell the tale of contact.

If I recall correctly you are in the Minneapolis area.  Take your crank down to Crankshaft Supply in Minneapolis; they can weld it and repair the thrust surface.

[Rory428]

Since you say that this is a 65 that had a CruiseOMatic, did you instal the steel "block plate" that gets sandwiched between the engine and the transmission, behind the flexplate? If not, the C6 would be located the thickness of the plate, further towards the engine than it should be. Also, being an aftermarket crank, and torque convertor, did you test fit the convertor into the crank, to confirm that the convertor snout had enough clearance in the pilot hole of the crank? Might be interesting to measure the distance between the stud base flanges, and the front of the convertor body, between a stock convertor, and the aftermarket unit.