trouble shooting...bad rod bearings

[Greenlee]

My buddy just bought a 69' M35-A2 with the multifuel turbo engine at auction. The truck is clean, but would not start. It appears to have about 15,000 miles and 600 hours. He replaced the fuel pump, and it fired up and seemed to run good at first. However, he drove it about a half mile and it began running rough and losing power. He got it home and it died and would not turn over.

After removing the oil pan, it appears the rod bearings are toast. He has ordered the parts to fix it, however, we are concerned because we don't know what caused this to happen. It appeared to have good oil pressue before it died. It had fresh looking oil in the engine. Almost too fresh, as if someone had just poured oil in it before the sale. The oil cooler has silicone and mismatched bolts as if it has been tampered with.

Does anyone have any ideas about what would have caused this?

 

[Armada]

What was the 'good' oil pressure reading? Strange that it was fine with bearings that bad. Sounded more like he was having a fuel related problem causing it to loose power and die.
Perhaps the bearings had been replaced and they never cleaned the pan before putting it back on. Pull the main and rod caps and gage them to be sure. Also try a mechanical oil gage on the motor to get an accurate reading of pressure if it will start up again.
Pappa-G had his bearings go bad when he first got his truck. The oil pressure was down to about 10 I think. He drained the oil and found big pieces of bearing material in it. Come to find out, the crank was bent.
Surprisingly, it ran quiet and smooth in that condition.
Good luck.

 

[Greenlee]

What was the 'good' oil pressure reading? Strange that it was fine with bearings that bad. Sounded more like he was having a fuel related problem causing it to loose power and die.
Perhaps the bearings had been replaced and they never cleaned the pan before putting it back on. Pull the main and rod caps and gage them to be sure. Also try a mechanical oil gage on the motor to get an accurate reading of pressure if it will start up again.
Pappa-G had his bearings go bad when he first got his truck. The oil pressure was down to about 10 I think. He drained the oil and found big pieces of bearing material in it. Come to find out, the crank was bent.
Surprisingly, it ran quiet and smooth in that condition.
Good luck.

He said it had 60lbs. oil pressure.

Could the oil cooler have anything to do with it? It looks like someone was pretty sloppy with the silcone when they worked on it. Is there something in there that could be clogged up?

 

[Greenlee]

We have a theory now that the oil cooler was bad and replaced by the military. The engine probably had water in it from the oil cooler being bad and was screwed before he got the truck.

I have told my friend about this forum and he can't wait to get on here. He has a hopped up Dodge diesel and was excited to hear that people are hopping up these old deuces. He doesn't currently have internet service so I am trying to help find some info for him. If anyone has any tips, tricks, or theories regarding his truck, please pass them along!

Thanks!

 

[Djfreema]

I have another duece I just bought and it too has a locked up motor. I have the heads off and the oil pan off. No bearing material in the oil pan, no scoring of the cylinders. Everything looks fine except It just wont turn over either. Ive sprayed wd-40 in the cylinders and let it soak thinking maybe the rings were rusted to the cylinders but It wont budge. The crankshaft moves freeley forward and backwards (slightly) so It cant be the main bearings. I know there was a member in San Diego that had the same problem however I think he sold the truck without fixing it. This is the 4th White multifuel motor Ive seen with this kind of problem. Anybody know of a flaw like this in these motors? My next step is to check the rod bearings.

 

[ken]

My guess is the oil filters. If the filters were on the shelf for a long time, they will loose some media. Mabye stopping up a oil galley. If the filters stopped up the oil cooler they may have taken it apart because of overheating. By this time the bearings were probally going down hill. The oil pump would still make good pressure but the oil might not be flowing. I would replace the oil pump. Before i put it together i would use compressed air and bolw out every oil passage i could find. There are plugs on the sides of the block where you can acess these galleys.

 

[Djfreema]

Well I just found that the #3 rod bearing had spun and the 2 bearing halves wedged on top of eachother creating a brake effect on the motor. The crank looks like its gonna have to be re ground. I dont have the time or desire to pull the motor so I'm contemplating using it as a parts truck for the 2 other recently acquired dueces I got. Anybody ever pulled the crank leaving the block in the truck?

 

[rdixiemiller]

That is a pain in the rear. It is much easier to pull the engine and get the crank out that way. I pulled a dozer crank one time, Jeez! You have to pull the tranny, clutch, flywheel, and everything needed to remove the front cover. Then you have to catch the damned thing when gravity takes over.
Try taking some 320 grit abrasive strip and shoeshine polish the journal. Carefully mike the journal. I have gotten lucky before and been able to save a motor. You will have to pop the head and change the rod, as it will be shot. Obviously you will need a full set of rod bearings.
Have you looked for an engine in the can? I see a lot on GL in Texas, not many in Cal.
I'll do the friend thing. $50 as it sits. $100 if you can deliver to Ga.
Just a thought....... I know, thousands of comedians out of work.......

 

[red devils dude]

Well I just found that the #3 rod bearing had spun and the 2 bearing halves wedged on top of eachother creating a brake effect on the motor. The crank looks like its gonna have to be re ground. I dont have the time or desire to pull the motor so I'm contemplating using it as a parts truck for the 2 other recently acquired dueces I got. Anybody ever pulled the crank leaving the block in the truck?

it's not worth it I tried

 

[Greenlee]

Well I just found that the #3 rod bearing had spun and the 2 bearing halves wedged on top of eachother creating a brake effect on the motor. The crank looks like its gonna have to be re ground. I dont have the time or desire to pull the motor so I'm contemplating using it as a parts truck for the 2 other recently acquired dueces I got. Anybody ever pulled the crank leaving the block in the truck?

Depending on how bad the crank is, you can polish it with emory cloth while it's in the truck.

 

[Greenlee]

UPDATE: Polished the crank and replaced rod / main bearings. Fired the truck up and let it run in the yard for about 20 minutes. It initially had about 120 lbs. of oil pressure upon start up.

Drove it a couple of miles and everything seemed fine. Started to drive it again and oil pressure dropped to about 15 to 20 lbs. and rod started knocking.

We are going to tear down the oil pump and oil cooler and look for anything that doesn't look right. The oil pump screen had some silicone in it last time, so we are thinking something still may be clogged up.

Does anyone have any other ideas? We are not sure what is wrong with this thing.

Also, what is the cheapest/best place to get new rod bearings? I think we overpaid last time. At least now we have all the part numbers.

Thanks,
Scott

 

[Greenlee]

Sorry, hit submit twice and posted twice.

 

[bomar76]

An obvious question...but you did plastigauge (or mike) the journals, correct?

 

[Djfreema]

Did you blow the oil passages out to make sure there werent any blockages?

 

[Armada]

Yes, sounds like a blocked oil passage.

 

[red devils dude]

check them(the journals) for true round if there not round it will eat bearings untell fixed.

 

[rdixiemiller]

Did you mike the crank journals? Also, I would plastigauge the crank to make sure you don't have a hammered out rod big end. You did replace the rod, didn't you? If the bearing spun, that rod is toast.

The 120 psi at startup concerns me. You may have a plugged oil hole in the rod journal where the bearing spun.