Fluid Drive Rebuild Or Parts Source?

[Jeff Balazs]

I spent some more time looking into the source of the squealing noise I am getting with this. It still comes and goes but it isn't going away altogether.

 

One thing I have done is pulled off the inspection cover and looked at it while running. There does dot appear to be any wobble in any of it. The noise goes away with light pressure on the clutch pedal. It does not seem to be coming from the throw out bearing or the transmission. Noise seems to be generated farther forward. When the clutch is depressed the entire fluid drive appears to move forward slightly....1/16" or so. Is this normal or is this an indication that the FD bearing is going bad? Not sure what to make of this.

As always any suggestions or ideas will be greatly appreciated.

Thanks, Jeff

[Dave72dt]

check the harmonic balancer for similar movement

[Jeff Balazs]

check the harmonic balancer for similar movement

Yes.. ....I was just waiting for a helper to check this. So is there a simple fix ? Or am I in for big job?

I had this apart last year and replaced the timing chain. It doesn't have a harmonic balancer....just a pulley.... and nothing is leaking.

 

Jeff

[TodFitch]

Yes.. ....I was just waiting for a helper to check this. So is there a simple fix ? Or am I in for big job?

I had this apart last year and replaced the timing chain. It doesn't have a harmonic balancer....just a pulley.... and nothing is leaking.

 

Jeff

IIRC, the fore/aft positioning of the crank is managed by the rear main bearing. . . If the crank is moving that much then it's time to open up the bottom end and do some repairs. Unless it is fairly specific issue you are probably looking at an engine worn enough to consider a full rebuild.

[Dodgeb4ya]

You can grab the fluid drive "vane part of the coupling" and try to move it froward and backward. Shouldn't move more than .003-.010". That will tell you if the crank has excess end play.

If the crank end play is ok the noise might be coming from the FD seal area and or the FD front bearing being worn out.

[Jeff Balazs]

You can grab the fluid drive "vane part of the coupling" and try to move it froward and backward. Shouldn't move more than .003-.010". That will tell you if the crank has excess end play.

If the crank end play is ok the noise might be coming from the FD seal area and or the FD front bearing being worn out.

No appreciable play in the FD. Looks like it is end play in the crank. I suppose that would explain why the noise goes away after it gets up to operating temp.

I could have done without this. Shame as the engine runs sweet. 135 # compression and 45# of oil pressure at idle. No smoke and tan plugs.

 

Jeff

[Dodgeb4ya]

Your statement above is telling that you have minimal end play. The reason I said to grab and push/pull  just the front vane/ring gear portion of the FD coupling-NOT the rear clutch part is that the front secttion is ridgedly bolted to the crankshaft and is the easy way to feel for end play movement  of the crank. If lower dust cover is removed and the FD coupling is exposed this is the best way. There is a lot of mass in the coupling and will make it obvious if there is "IE" 1/16"-1/8" of bad front to rear end play (back and forth) of crankshaft movement . You want to be sure you are checking this crankshaft end play accurately or you will end up rebuilding the engine and putting it all back together just to have the same problem. On a good engine you will not feel much if any end play in the crankshaft.

Edited September 12, 2013 by Dodgeb4ya

[Jeff Balazs]

Your statement above is telling that you have minimal end play. The reason I said to grab and push/pull  just the front vane/ring gear portion of the FD coupling-NOT the rear clutch part is that the front secttion is ridgedly bolted to the crankshaft and is the easy way to feel for end play movement  of the crank. If lower dust cover is removed and the FD coupling is exposed this is the best way. There is a lot of mass in the coupling and will make it obvious if there is "IE" 1/16"-1/8" of bad front to rear end play (back and forth) of crankshaft movement . You want to be sure you are checking this crankshaft end play accurately or you will end up rebuilding the engine and putting it all back together just to have the same problem. On a good engine you will not feel much if any end play in the crankshaft.

At this point I am pretty sure there is some end play in the crank. With the inspection cover off you can see the whole FD including the ring gear move forward when you depress the clutch. Also you can see a bit of movement at the front engine pulley when the clutch is depressed. When I checked the FD with the inspection cover off I could not feel or see any movement by just pushing on the front section by hand. You probably could get movement if you used some sort of lever....but I chose not to. I don't have the equipment to measure how much it is moving but I can definitely see it move.

 

I put it back together and ran it for about 15 minutes. The sound goes away after about 10 minutes running time. I suspect this has to do with the metal expansion at operating temp. I don't really want to do a rebuild at this point. I am finally about a month or so away from being able to get this registered after almost 2 years of ownership. I think I am going to try running it as is for a while and maybe start looking for a spare engine to have professionally rebuilt. Preferably by someone who has done several of these and knows all the ins and outs.

 

Jeff

[Dodgeb4ya]

You might get a second opinion on crank end play before you condem it. Flathead thrust bearings can wear (I've read respnses here on this) but I have not seen it in any I have worked on. Over the years at least 2-300 of them!

[De Soto Frank]

With the crankshaft, axial thrust is taken by the rear main-bearing.

 

MoToR's 1935-'49 quotes 0.003"-0.007"  crankshaft end-play as allowable.

 

The Shop manual further shows end-play being measured at the rear main, between the bearing flange and the cheek on the bearing journal.   "If too much clearance is present, replace the bearing."

 

Before replacing the rear main, it would be good to check the clearance between the journal and the bearing shell;  again, service tolerances are between 0.0005" - 0.0015".  If not worn beyond 0.002" , you can probably install a new standard-clearance main bearing shell as a get-by.

 

You can check all this out with the engine in the chassis, by dropping the oil pan.

 

You MIGHT be able to get an accurate reading on axial play (thrust) in the crank without dropping the pan by using a dial indicator either on the damper pully, or back on the fluid coupling housing.

 

As Dodgeb4ya mentioned, do not observe movement / take measurement on the drive-plate & clutch assembly,  but rather on the fluid drive housing (fins forward).

 

Be careful areound those cooling fins: they have sharp edges  !

 

Good luck !

[Jeff Balazs]

Frank;

Thanks for your response. Do you know it is possible to replace this bearing shell with the engine in place? I am not at all familiar with the bottom end on these engines....so excuse me if it is a dumb question.

 

Jeff

[Merle Coggins]

Yes Jeff. You should be able to roll in a new bearing shell. But if you're going to go through the trouble, I'd have a full set of lower end bearings on hand and possibly to them all while you have the pan down.

 

Basically you drop the cap, then locate the lock tab end and push up from the other end with a screwdriver or narrow bar to get the bearing shell to slide around the journal. I've even heard of sliding a thin headed rivit into the oil hole on the journal and rotating the crank. The rivit head will catch the edge of the bearing and roll it out. Then you clean things up the best you can and slide the new one in in reverse order, lubing only the bearing to journal surface. Put the other new half in the cap and reinstall.

 

Merle

[Jeff Balazs]

Thank you Merle;

This sounds do-able. This engine had been rebuilt and when I dropped the oil pan things looked really clean. Bit of sludge but nothing to indicate any serious issues. In fact it was so clean that I did not think it necessary to probe too much. It has 50 over pistons and 10 under bearings according to the tag I discovered. The bores looked good and mic'd out close to perfect for the 50 over pistons. Based on what I found I figured it still had a lot of miles left on it. I had a few friends look it over when the head was off and we all thought that the way the bores looked it probably only had maybe a hundred hours or so on the rebuild. In retrospect I suppose I should have delved deeper.

 

I did install a new timing chain.....had the head resurfaced......new distribution tube......new head bolts  etc...etc...

It runs really well....at the moment......and of course I would like to keep it that way.

 

Jeff

[De Soto Frank]

Jeff,

 

See if you can dig-up some MoToR's or Chilton's shop manuals of that era ( 1940's-'50's )...  while there was a purpose-built little widget made for turning the upper main bearing shell out with the engine in place ( looks like a little pin wih a floating cross-tab across the one end:  pin goes into the oil hole in the bearing journal of the crank, and the little cross-piece lays parallel to the journal surface, and catches the edge of the upper bearing shell, nudging it out as the crank is turned.  A makeshift tool can be made from a cotter-pin, flattening the pin head and inserting the long part into the oil hole.).

 

If you go to spin the upper shells out, loosen ALL the main bearings a little, and turn the crank in such direction that the locking-tab on the shell backs-out of the block.

 

I don't know if any aftermarket thrust shims were made for the MoPar sixes, or bearing shells with thicker thrust flanges...

 

Take your time... let us kow how things are progressing.

 

Frank

[Dodgeb4ya]

If the crank rear thrust bearing is the problem the crank thrust flange and old bearing both need to be carefully looked at. Putting new bearings in an engine with a worn crankshaft rear thrust flange will last a week if that.

[Jeff Balazs]

Jeff,

 

See if you can dig-up some MoToR's or Chilton's shop manuals of that era ( 1940's-'50's )...  while there was a purpose-built little widget made for turning the upper main bearing shell out with the engine in place ( looks like a little pin wih a floating cross-tab across the one end:  pin goes into the oil hole in the bearing journal of the crank, and the little cross-piece lays parallel to the journal surface, and catches the edge of the upper bearing shell, nudging it out as the crank is turned.  A makeshift tool can be made from a cotter-pin, flattening the pin head and inserting the long part into the oil hole.).

 

If you go to spin the upper shells out, loosen ALL the main bearings a little, and turn the crank in such direction that the locking-tab on the shell backs-out of the block.

 

I don't know if any aftermarket thrust shims were made for the MoPar sixes, or bearing shells with thicker thrust flanges...

 

Take your time... let us kow how things are progressing.

 

Frank

Thanks for your response Frank.

So I take it these manuals have more information in them regarding these sorts of repairs ?

The shop manual I have....Dodge Trucks Shop Manual B-3 series......does not have a lot to say. I honestly don't know that much about this topic. I guess I have been lucky up til now as I have never had an auto or truck engine that ever had crank related problems. What little I know is all motorcycle related and does not help at all with this.

 

Is this a common wear area with these engines? Or is this something that was brought on by poor assembly when it was rebuilt years ago?

I am really bummed. Other than this the thing runs very well. I have put a ton of work into this truck and at this point I really wish I would have gone another route with it.

 

Jeff

[Dave72dt]

It's an age issue or mileage issue or maintenance issue. Whoever rebuilt it last either did not inspect that area or deemed it not an issue to worry excessively about. It's easily inspected with the pan off, everything you need for tips and tricks to replace it has been mentioned. Excessive wear will be on the thrust surfaces of the brg, crank surface or both. Cranks can be welded and reground. Until you know exactly how much end play you have, it's not that big a deal. They don't get excessive over night. That movement may not be your noise just because the movement and noise happen at the same time.

[De Soto Frank]

Engines in manual shift vehicles probably are subject to more axial thrust in the crankshaft than in those with automatice transmission, due to the action of the clutch in shifting gears.

 

I can understand your frustration;  hang in there and check things out.

 

Is the noise just present enough to get your attention and cause concern, or it it a piercing screech like some 10 year-old beater with loose belts that some clod keeps on driving that way ?

 

 

Also, if you get into dropping the pan to check thrust clearance,  suggest doing so with the engine at operating temperature.  You mentioned that the nosie goes away once the engine is thoroughly warm:  it would be ideal to check the thurst clearance with the engine at oeprating temperature, and again when it is cold.

 

Perhaps you can check this out by removing the bell housing inspection pan, rather than the oil pan...

 

Just some brain-storming....

[Jeff Balazs]

Thanks Frank;

I appreciate your comments. It is totally frustrating.

I think what I will do is get a machinist buddy of mine to help me check this. He has all the right types of equipment to measure this accurately. And he is an old car and bike nut. Maybe we will try and get a reading at the inspection pan and the front pulley first. The noise is not that bad yet. Just a faint squeal that goes away after it warms up. It is more annoying than anything else. To be honest when it first started I thought I had overtightened the fan belt.

 

I would like to try and nurse it for a while. I am trying to get it ready to register after almost 2 years of ownership. It would be great if I can keep it running for a while so I can save up for a proper rebuild or a new engine. I am thinking I may put straight 40wt in instead of the 10-40 that is in there now and just keep my fingers crossed.

 

Jeff

[De Soto Frank]

Speaking of belts, have you tried running it with the fan-belt removed ?

 

Genny and water pump bearings sometimes make noises that are hard to isolate...   just another thought...

[Dodgeb4ya]

I'd drive it for the time being, but have your machinist buddy give his opnion. Doesn't sound like it's about ready to blow!

[Jeff Balazs]

Thanks Guy's;

I am going to keep a real close eye on it. Will try to get my buddy over in the next couple of weeks to try and get some measurements. I just don't have those sorts of tools. In the mean time I don't have to run it.....I am in the middle of wiring and finishing the interior so plenty to do.

 

What do you think of running a heavier grade oil and maybe some STP or another additive until I get set to actually correct this?

 

Jeff

[HanksB3B]

Jeff,

I'm not advising rather asking.  Some people I respect say that STP is a good thing to add and I can't remember just how often and just what it does.  I thought an oil that has a thinner viscosity reaches more places in the engine.  With the way oil technology has changed and the advent of synthetics is STP a beneficial additive.

 

Wondering what the noise that goes away is ?  Mine was fairly simple:

 

 

Have faith.  You'll get it !

 

Hank 

 

P.S. Keeping busy with other things is a good way to not screw something up by approaching it with a frustrated state of mind

Edited September 16, 2013 by HanksB3B

[Jeff Balazs]

I managed to track down the source of the noise I was hearing. Turns out it is coming from just behind the engine pulley. I think it must be caused by the combination of a new seal on the timing case and a bit of wear on the pulley hub. A shot of oil and it goes away for a while. Press in the clutch and it goes away. It is not too obnoxious and it does not sound like metal on metal.

 

I am not sure if this is really anything serious or if it will be OK to run like this for a while. This seal does not appear to be leaking nor do I have any leaks any where else. I am wondering if I can nurse this by occaisionaly giving it some lube and buy some time to save money for a complete rebuild?

What do you guy's think?

 

At this point there is no question in my mind that the crank is moving forward slightly when the clutch is applied. Looks to be on the order of a 1/32" to 1/16" or maybe even less but I have not had the opportunity to get a real measurement. Other than this the engine runs fine. It has always been my intention to do a full rebuild but I have pretty much used all my funds now to get the truck to this stage. Hopefully I will be able to drive it for a while withoutdoing any serious damage and then get it rebuilt properly.

 

Jeff

[Dodgeb4ya]

The rubber lip might be (is) dry on the hub. On some newer GM trucks  there was a noise sqeal issue on the outboard hub seals. They issed a bulletin giving a new sea l# to fix the issue. Rubber was wrong formulation.

But another question... did you install this type of seal with a internal curved metal oil slinger lip? It can hit the timing gear/chain if not carefully pressed in the timing cover.

Bob

Edited October 8, 2013 by Dodgeb4ya