Thrust bearing terror

[cerberusiam]

Is there any abnormal wear on the rod bearings? Do the rods only go on one way? I wonder if a slightly tweaked rod would cause the excessive force on the thrust but not enough to cause other problems. The only other thing I could think of would be a stress crack somewhere in the block that is allowing it twist under load.



I wonder if a bad cam would cause any isssues with the loading?



Just thinking out loud.

 

[DValentine]

Just some thoughts here. In school, I remember a lot of talk about alignment of the bell housing, and runout on the flywheel. I know this is an auto, but the theory would be the same.



dave

 

[ScottDixon]

Sorry I have not been able to log on for a while. Password missunderstanding. Yes the rods and bearings have abnormal wear on them, both indicating something pushing forward. The block is being rechecked for cracks right now, especially in the main webbing. And Iguess I Don't see how a cam could cause the problem, but I won't rule anything out.

 

[ScottDixon]

Flexplate runout is terrible on every 5 9 Dodge I've worked on, this one being no exception. Bell housing alignment hasn't bein checked yet,as the trans. front pump will have to be removed and the crank center line indicated to the pump bore in the trans. case, but this should be done. Last of all, I am going to abort this trans. in favor of a differant one. Thank you for all of your support and patience.

 

[MMiller]

*IF* the cam gear is meshed directly with the crank, and something is not quite right it *could* be pulling the crank forward. I *think* this is what others may be hinting at. I was kinda wondering that in my first post. Helical cut gears will have side load on them, due to the angle of the gear teeth. They are quiter and stronger, but you get a side load. Straight cut gears will not have a side load, but are noiser, and have less tooth contact. That is why I asked if the gear train was helical cut. Sorry I was not clearer. I also have not been in the front cover to know if the cam directly meshes with the crank gear.



I hope you find something soon. I don't know if I could put it back to gether and in the truck to see if it does it again. Can you put it on a test stand and run it if you find nothing "wrong"? I guess you could put a junk convertor on it to get the engine started.



Michael

 

[ScottDixon]

Helical cut on the timing gears. Hm. The angle is about 15 degrees, and normal engine rotation would cause a slight forword pull on the crank. If the cam gear runout was excessive it could aggrevate this, but the runout in my motor is well within specs. All B series cummins motors, to my knowledge have this type of gear train, and most go without thrust problems,but I'm still thinking. I'll share one other thing I was thinking about that I haven't already discussed. I think my thrust failure occures under load. The 2nd failure happend when I had a 20,000 lb. trailer and load weight, excellerating from a standstill, I heard a loud scraping noise. If I let off the throttle it went away, or revved the motor in neatral it was quiet, but put it in gear and romp on it and it was back. The noise of coarse was the convter bolts and flexplate rubbing on the engine adapter. Thanks again for all the suport.

 

[MMiller]

Surely the convertor was not "balloning" was it? Or maybe something is goofy in the tranmission?



Michael

 

[ScottDixon]

The trans. shop that rebuilt the transmission said the converter was rebuilt, but I really wonder if they didn't just clean it up and call it good. Anyway I'm not taking a chance on that trans. or converter . I'm just puting in a complete new assembly. That will take the trans. out of the picture. Scott

 

[BushWakr - RIP]

Is it possible the gear internal cover/case has had the/some of the bolts loosen off and is allowing some "creep" ????..... I dunno, just thinking out loud here...



pb..... giving the holy repair beads a workout here bud...

 

[bmoeller]

It'd be puking oil then, I would think, if that were the case.

 

[BushWakr - RIP]

No I didn't mean the gear case tin cover, but rather the internal gear casing itself... the one you find bolts loosen off on inside... .



bob. .

 

[phillips5]

I was in a hurry so I didn't read every reply on this one so I hope this isn't a repete but how is the oil supply to the thrust bearing. Is the hole ploged ( did a catipiller crawl up the feed hole or something.

 

[bmoeller]

No I didn't mean the gear case tin cover, but rather the internal gear casing itself... the one you find bolts loosen off on inside... .



bob. .

I understood that. Couldn't it still leak? There is a gasket involved there, too. Correct?



I tightened those bolts too, when I took care of the KDP.

 

[B.G. Smith]

Surely the convertor was not "balloning" was it? Or maybe something is goofy in the tranmission?



Michael

If the converter has been replaced that would be my number one suspect. It could be flexing as suggested above causing the forward thrust. bg

 

[bmoeller]

Update? Was the problem fixed, cause?