Ed's 77 Terex 72-41

[mountainguyed67]

I’m gonna be back up there soon. I will check for heat at the exhaust, and maybe pull the valve cover.

 

[zlssefi]

Ive used 15 w40 for years without an issue

 

[mountainguyed67]

Ive used 15 w40 for years without an issue

In a 2 cycle Detroit?

 

[DB2]

They prefer a single over a multi grade. Something with low ash content. Post this specific question alone and the experts will weigh in.

 

[oarwhat]

Oil rated CF-2 is for Detroit 2 stroke engines. Use only straight weight 30 or 40. CF-2 is a low ash oil made for 2 stroke engines. Delo 100 is a CF-2 .

 

[zlssefi]

In a 2 cycle Detroit?

Yes. I know they call for straight 30 wt but i run 15w40 in all of my big diesels so my 471 gets it too. Havent had any issues in 20 years yet.

 

[mountainguyed67]

I started the engine and checked for heat at the exhaust manifold. Three cylinders were getting too hot to touch, and I could still hold my hand against the fourth. It was cold. The cylinder closest to the bell housing. Might get the valve cover off today.

 

[kshansen]

I started the engine and checked for heat at the exhaust manifold. Three cylinders were getting too hot to touch, and I could still hold my hand against the fourth. It was cold. The cylinder closest to the bell housing. Might get the valve cover off today.

Sounds like it could be an injector problem. Could be other things but let's hope it is the injector!

Let us know what you see when VC is off.

 

[mountainguyed67]

I went to take the valve cover off, there was dirt and crud around it. I remembered reading in the manual to clean first to avoid getting contamination inside, it looked like that would happen. I will take the pressure washer next time.

If you’re wondering about the tree branch, I dropped the clamp nut and wanted to keep it closed up in the meantime. I put plywood over it before I left too.

That’s the steering tank above the engine.

 

[kshansen]

If you’re wondering about the tree branch, I dropped the clamp nut and wanted to keep it closed up in the meantime. I put plywood over it before I left too.

Is there a part number in the Detroit book for that holdown?

And not to wish any bad luck on you but if you find that you do have a stuck injector I have a feeling which one it will be!

 

[mountainguyed67]

Is there a part number in the Detroit book for that holdown?

I haven’t looked. I assumed the nut would be captured in there, and so I didn’t look at it. Looking at it afterwards I think it’s an oversized square nut.

 

[mountainguyed67]

And not to wish any bad luck on you but if you find that you do have a stuck injector I have a feeling which one it will be!

How will I know it’s an injector? Process of elimination? If the valve train is good, it’s the injector.

 

[oarwhat]

Not an expert but just went through this. You will most likely see a plunger stuck down.

 

[kshansen]

Not an expert but just went through this. You will most likely see a plunger stuck down.

That would be the first things I would be looking for, you would have to turn engine over to be able to see it.
Turn engine by hand to get the valves open on one cylinder at a time and look for one injector where there is a gap between it's rocker arm and the plunger.

Another quick check would be to carefully remove the pin that connects the rod from the governor to the tube with the levers that operate the injector racks and make sure all the racks move in and out nice and free. I say carefully remove the pin as there are oil drain back holes in the head right near where you are removing the pin and you don't want to drop the pin or cotter pin! A small rag tucked under the lever can be a good safety net!

Any questions once you get valve cover off post a couple pictures of what you are seeing! I know you have the manual so that will be of some help, one of us can probably tell you the chapter number you need to go to for more detailed information.

 

[mountainguyed67]

once you get valve cover off post a couple pictures of what you are seeing!

Not sure I can get good pictures with the steering tank over the engine.

 

[kshansen]

Not sure I can get good pictures with the steering tank over the engine.

Give it a try even if not the best someone might be able to spot something! Even if you can't get the part under the tank!

 

[mountainguyed67]

I got the second cylinder apart, it’s in better condition.

This doesn’t need machining, it looks good enough.

Nut is missing the Teflon.

 

[oarwhat]

Teflon holds the nut from loosening. I'd just use red locktite to hold it

 

[sawmilleng]

Seems to me that you might want to check the torque specs for the piston nut. They are usually very high. The guys with cat access should be able to tell you what is recommended.
I wouldn't be surprised if it was in the 300 ft-lb range. A new nut with the nylon lock would be good insurance.

Jon.

 

[kshansen]

Refresh me on the number for the cylinder so I can get info if possible off SIS.