Too much thrust ....update

[flyinlow]

Normally In my line of work I do not complain about excessive thrust being a problem. However when the crankshaft of my 440 moves .040" front to back I think I have too much thrust. ( a light rattle at idle recently)

When I built the engine 50K miles ago I put a 69 crank .010 under in a 76 block. Thrust .006 or so. The engine runs fine, and has great oil pressure. Melling HV pump ,Mobil 1 15w-50

What makes the trust bearing wear on an automatic car?

I would like to drive the car another 1000 miles this season, then repair this winter. Will it do much more damage?

[Challenger340]

Engine guys blame trans guys, and trans guys blame Engine Guys.... back and forth for decades.

I'm an engine guy, so I blame Torque Converter trying to push the Crank out the timing cover. My rationale is the Crank should be "floating" in the Block with no thrust in either direction, and certainly not enough to kill a thrust.

You will know upon teardown, highly unlikely BOTH sides will be killed, but the one side that is killed, I'm betting will be the rear = some trans related pushing the Crank ahead.

[flyinlow]

Engine guys blame trans guys, and trans guys blame Engine Guys.... back and forth for decades.

I'm an engine guy, so I blame Torque Converter trying to push the Crank out the timing cover. My rationale is the Crank should be "floating" in the Block with no thrust in either direction, and certainly not enough to kill a thrust.

You will know upon teardown, highly unlikely BOTH sides will be killed, but the one side that is killed, I'm betting will be the rear = some trans related pushing the Crank ahead.

Hmmm...   I have  a 518 trans bolted to the engine thru an Ultrabell. Stock 360 converter /flex plate.  I will unbolt the converter and check free play.

If I remember latter blocks use a different thrust bearing. Would a 69 forged crank cause problems in that block?

So can I drive to a couple more car shows this fall? (800-1000 miles) with the crank dancing .040"

[John_Kunkel]

My rationale is the Crank should be "floating" in the Block with no thrust in either direction, and certainly not enough to kill a thrust.

When the auto trans is in gear the converter is pressurized which keeps the converter pushing on the rear of the thrust bearing. Obviously, millions of thrust bearing have survived with this constant load but it is possible for an internal failure in the trans to over-pressurize the converter and overload the thrust bearing.

[68CoronetRT]

Stock converter? There's your problem. Any kind of HP build you NEED a decent converter.

My buddy with a turbo LS motor has gone through 2 engines now because of a cheapo converter. Dont skimp on the converter. PTC is 495$ shipped to your door and has all the anti ballooning plates come stock.

500$ is cheap compared to the labor/parts to tear an engine down.

[flyinlow]

My rationale is the Crank should be "floating" in the Block with no thrust in either direction, and certainly not enough to kill a thrust.

When the auto trans is in gear the converter is pressurized which keeps the converter pushing on the rear of the thrust bearing. Obviously, millions of thrust bearing have survived with this constant load but it is possible for an internal failure in the trans to over-pressurize the converter and overload the thrust bearing.

Could the pressure change from a shift kit do this or are you taking about the force from driving the impeller?

[firefighter3931]

I'm betting that the converter ballooned and wiped out the thrust bearing...

A stock 360 converter is no match for a 500HP 440 



Ron

[flyinlow]

Damn. I was going to replace it with a better one. Just never got to the top of the list.

[flyinlow]

When the auto trans is in gear the converter is pressurized which keeps the converter pushing on the rear of the thrust bearing. Obviously, millions of thrust bearing have survived with this constant load but it is possible for an internal failure in the trans to over-pressurize the converter and overload the thrust bearing.

So John, should I check the line pressure and cooler line pressures while driving?

[flyinlow]

I talked to Hughes Transmissions and they recommended their 15-30L lock up converter Roughly 3000 rpm stall. No anti balloon plate , but it has a billet housing . For up to 650 ft.lbs of torque.

http://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?Ntt=15-30l&requestYear=&storeId=10001&catalogId=10002&langId=-1&year=&make=&model=&submodel=&engine=&Nrpp=&No=&persistYmm=false

Any flex plate recommendations? (stock now)

[cdr]

I would drop the oil pan & replace the thrust main bearing,inspect the crank. I used a 440 source SFI flex plate on my 512ci a518

[flyinlow]

CDR what converter are you using?

Yea, I am going to drop the pan and have a look. Might get lucky and the crank is not damaged. (ok it could happen)  I got a Moroso road race pan to install anyway.

[Kern Dog]

Normally In my line of work I do not complain about excessive thrust being a problem.

You don't work at a sperm bank, do you ?   

[flyinlow]

No , that job was already filled when I got there.

[cdr]

CDR what converter are you using?

Yea, I am going to drop the pan and have a look. Might get lucky and the crank is not damaged. (ok it could happen)  I got a Moroso road race pan to install anyway.

It was built by Precision converters of New Hampton, so far it has done ok. I would recommend calling PACT & talk to them on what you need.

[Kern Dog]

No , that job was already filled when I got there.

[cdr]

Flyinlow, also make sure the converter snout to crank does not bottom out when the converter is pushed up against the flex plate, there should be .120-.188 room AFTER the flexplate contact of the mounting tabs of converter, if not it will wipe out the thrust bearings.

https://www.google.com/url?q=http://board.moparts.org/ubbthreads/ubbthreads.php/topics/1684401/re-thrust-bearing-failure.html&sa=U&ved=0ahUKEwj_wcrTh6fXAhVH3IMKHeERDucQFggWMAk&client=internal-uds-cse&cx=partner-pub-0048081641434287:2223449621&usg=AOvVaw1oCWcpCZNGLfbZnkniHrxT


https://www.google.com/url?q=http://board.moparts.org/ubbthreads/ubbthreads.php/topics/1710971/727-converter-to-flexplate-clearance.html&sa=U&ved=0ahUKEwidyfy9iKfXAhUm9IMKHSuhCMsQFggEMAA&client=internal-uds-cse&cx=partner-pub-0048081641434287:2223449621&usg=AOvVaw0pGSKGZ_Cptj5FdSM5hkNo

[flyinlow]

Thanks CDR,

The Charger got put on the back burner  for a while , but should get back to working on it next week.

I will unbolt the converter and check for front to back clearance. I knew it had to have some . Looks like it should be .250 " feeplay.

So to check the snout you pull the converter taps up to touching the flex plate. Then take a converter to block measurement. Then spin the  converter an eighth of a turn an see if the converter fill move further forward. Measure this.

The converter should slide  .120-.188 farther forward when the tabs are between the flex plate arms?

[cdr]

Thanks CDR,

The Charger got put on the back burner  for a while , but should get back to working on it next week.

I will unbolt the converter and check for front to back clearance. I knew it had to have some . Looks like .250 " feeplay.

So to check the snout you pull the converter taps up to touching the flex plate. Then take a converter to block measurement. Then spin the  converter an eighth of a turn an see if the converter fill move further forward. Measure this.

The converter should slide  .120-.188 farther forward when the tabs are between the flex plate arms?

That should work unless you have a solid flex plate like mine, some say use alum foil in the back of crank, crush it & pull it out & measure how thick it is.

[flyinlow]

Finally got back to some checks on the transmission. My 73 FSM says minimum 1/2 inch between the mounting pads and the transmission flange to engine mounting surface.  A 1/2 bolt will almost fit snugly

Converter bolt head to engine (ARP bolts) .125".

When you rotate the converter so the lugs are between the flex plate arms (45*  from where it is normally) I can not move the converter farther forward. You can turn the converter while pulling it forward and the lugs just clear the flex plate. The converter body is not in contact with the flex plate. Might have a snout to crankshaft problem.

Total front to back converter movement with a light pry bar force (converter unbolted) is .075" The converter ring gear flange to engine shows 1 to 1 3/32 when pried front to back. I don't think that is enough.  

I rotated the converter while pushing rearward. It did not seam to be scraping against the Untrabell housing or the pump. I will look for scrapes/ interference on removal.

I have two stock A518's sitting in the garage . I will compare the converter depth  to them.

Of course I will not be using this converter after I repair the engine, but I think I need more clearance .

Might need to space the transmission back with washers.  

[flyinlow]

Checked the two A518's I have in the barn. Both show about 1 1/4 inch convert ring gear flange to mounting surface. About 3/16 " deeper than the one in the car with an Ultrabell bolted to the pump.

The  727 transmission I had in the car before the A518 shows 1 1/8 inch  ring gear flange to mounting surface.

[John_Kunkel]

The rear side of the flex plate, when installed on the crank flange, should be about 3/8" from the block mounting flange; this, in combination with the 1/2" minimum lug depth allows for 1/8" of pull-up to the flex plate.

The pilot hub on the converter shouldn't bottom in the crank before the drive lugs contact the flex plate but, if it does, a few thousands shouldn't cause any problems. Nothing you describe, transmission wise, should cause a thrust problem.

[flyinlow]

The rear side of the flex plate, when installed on the crank flange, should be about 3/8" from the block mounting flange; this, in combination with the 1/2" minimum lug depth allows for 1/8" of pull-up to the flex plate.

The pilot hub on the converter shouldn't bottom in the crank before the drive lugs contact the flex plate but, if it does, a few thousands shouldn't cause any problems. Nothing you describe, transmission wise, should cause a thrust problem.

That leaves me out of things to check before tear down.

I am thinking about a Hughes Billet converter . If the numbers are the same with the new converter, what do think about adding spacers between the engine and transmission?

[flyinlow]

Finally  pulled the oil pan and number 3 main cap. The engine had the shorter flange pre 74 style trust bearing. (my engine is a 1976 and came with tall flange trust bearing))The crank was not scratched or grooved. The trust bearing appeared to take all the beating. I have a 440 block with a stock cast crank and the late model bearing still it. Of course the flanges are taller but the used bearing was .012" wider than the shorter flange I removed from the car.. I put the used tall flange bearing in the crankshaft in the engine in the car and it fits well . Little front to back movement. I put the short flange bearing I had just removed back in the crankshaft in the car and there was noticeable slop.

I order a set of tall flange main bearing . I lowered the crank enough to remove the  top half of the #3 main. I plan on installing the new trust bearing and putting it back together and see how it works.

Installing a Milodon 7qt. road race pan while I am in there. Only thing that fits a 73 without hanging below the k frame.

[flyinlow]

New Thrust bearing works fine. End play at .010

Milodon Road Race pan/windage tray installed with 8 Qts. of Mobil 1  0W-40. Should be an improvement. This was not the bolt in that Milodon claimed (surprise) Minor Idler arm support cutting and welding required.
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