Thrust bearing terror

[ScottDixon]

My 93 cummins went 200,000 miles and shelled a thrust bearing. Since this it has done in two more in short order. The trans. has been rebuilt, cooler flow checked, converter replaced, and many other things checked. Two machine shops missed a crack in the crank, but the third thrust bearing was with a different crank and still show some evidence of forward force on the crank, although not as bad. I "ve built hundreds of motors with varius problems, but never has one stumped me like this. Any ideas that I may have overlooked?

 

[JLEONARD]

I'm not ignoring your post... . I'm thinking. There is something putting an axial load on the crank... but not knowing autos very well I'm comming up empty right now.

Jay

 

[MMiller]

I'm just thinking out loud here. Could the accesory belt or something in the front cover be pulling the crank forward? Are the gears staright cut or helical? I cannot imagine there being a problem in the auto that would hurt the engine and not destroy the auto.



I too am not ignoring you. Just completely stumped.



Let us know anymore information, no matter how off the wall.



Michael

 

[cerberusiam]

Has the crank line bore been checked?

 

[Joseph Donnelly]

What is the end play at the thrust surface? Check the block closely for cracks in the main web area. Check the tightness of bearing fit.

 

[bmoeller]

BG-



Auto trans in that truck.



cyote-



I'd start where Joe suggested. Sounds like the crank is still being allowed to move to much. Does the engine run smooth? Need a new vibration damper?

 

[B.G. Smith]

BG-



Auto trans in that truck.

Oops. Thanks b. bg

 

[CLiberty]

What is the endplay on the crank when the repairs were done? If it was re-assembeld with excessive endplay there is no way it`ll live, even with a new thrust bearing. I would scrutinize the the thrust surfaces on the block very closely, i. e. make sure the surfaces are flat and parallel (main cap and block in same plane) and make sure thrust clearances are in spec, simply putting in a new bearing may just be "bandaiding" the problem.

 

[HRajagopal]

Edited:



These are great engines, couldn't be a design flaw that causes the continued thrust bearing issue.



Sounds like you've checked about everything it could be anyway.

 

[MMiller]

I have never had the bottom end apart on a 5. 9. I have had Cats apart, and the main caps can be installed wrong. Is the main cap for the thrust bearing installed correctly? Not turned around?



Michael

 

[bmoeller]

Hmmmmm. Somebody has his boxers in a wad.



HRajagopal-



What problems have you had with Cummins? Do you work on them, or just wanting to be an ah?



I've run a lot of them, and never had one lick of trouble. 3. 9L, on up to the N-14.

 

[HRajagopal]

Edited:



Might just find another engine (they're $1,100-1,500 around here) and freshen it up, might be less $'s that what you've been through on that one.

 

[JLEONARD]

This really turned into a great thread... .

Hows about you guys gettin' back tp the business at hand?

Thanks.

Jay

 

[bmoeller]

One more thing... . , I don't wear boxers mr. smarty pants. I wear my wifes panties.

Was thinking it, just didn't say it.

Well... , lets see... , you mean besides the KDP falling out, the lift pump going out TWICE in its 108K, the oil cooler blowing up, the spring pin on the IP wearing out, the shut-off coming to pieces (blame on Bosch, not cummins), the crappy STOCK CUMMINS thermo's (and it's a good thing I don't have one of those brazillian blocks and one of those IP's that last a whopping 100K - oh wait, the IP WAS replaced at 62K on it??) Of course, all the thousands that was saved by cummins in not putting in block plugs so it can be drained properly went to engineering salaries (or maybe not?)



I could find a million stupid design problems and shortcuts with this engine, but I suspect they came about to effect production ramp-up for Dodge. Of course, most of the really annoying (and broken) things with the truck are a Dodge issue and not Cummins anyway.

KDP, t-stat & frost plugs- Cummins



Oil cooler- don't know the source (pressure relief {by-pass} problem?)



Fuel injection pump- Bosch



LP- Carter (?)

-------------



OK. When (year) did the fuel inj. pump go out? When the lower sulfer diesel came out in the '90's, you weren't the only one with a failure. I had to replace one on a tractor (either a Roosa-master or Stanadyne distributor type [same style as the VE on the Cummins], don't recall), and knew several people who had to replace some at about the same time. The one I replaced, wasn't all that old. Another cause could've been a bad/plugged fuel filter. VERY tight tolerances.



Why Cummins didn't the hole for the KDP a blind hole, who knows. Stupid idea. I caught mine in action, before anything happened. What mileage did yours fall out?



Sounds like Cummins wasn't the cause of most of your problems. Just the suppliers.



FWIW.

 

[ScottDixon]

the belt is running straight and has a new tentioner. the timing gears are helicl cut.

 

[ScottDixon]

line bore is straight within . 0015 inch. it is round within . 001 inch and to size.

 

[ScottDixon]

crank end play was . 007 inch on assembly. block was magged. bearing fit seemed normal.

 

[ScottDixon]

the engine runs great even with a bad thrust, no vibration evedent. the damper runs straight, no wobble and looks good.

 

[ScottDixon]

end play was . 007 on assembly. the block is at the machine shop right now for another round. I stressed to check for cracks in the main webbing was very important.

 

[BushWakr - RIP]

Let's stay on task with this thread guys... I don't want and won't entertain a thread degenerating into a "cuss out".....

We've never had to worry about that sort of thing in here and it won't happen on my watch... .

Now, to be fair AND up front... if you have a personal experience(s) with the product you can most assuredly post those experiences with factual info and not need to resort to disguised profanity/cussing/cursing out to make your point.



Lets help cyote diagnose and repair his problem rather than throwing stones...



Please, keep it clean and fun... . just like this particular Forum is well noted and regarded for among the other groups... .



pastor bob... .



edit: Joe D. and all the other guys have good insights into these old girls and they often nail it down pretty quick.

If you want a bit more "personal" dialogue, try calling the shop I hang out at... PDR. Give the shop a call and ask for Piers, he may well have some very specific things to look for/at to find your problem.