Valve lash adjustment?

[joea99]

While running the B21 engine searching for an elusive fuel leak, thought there was some "valve clatter". While that may be normal, I went looking in the WSM for a procedure and maintenance interval. Did not find any. Perhaps I missed it.

Any published spec and procedure?

 

[number two]

Surely it is in the WSM somewhere.
The adjustment interval for Kubota seems to be 800 hours.
That would be listed in your Operators Manual under maintenance schedule.
The procedure would be under engine,perhaps cylinder head?

Good Luck!

 

[joea99]

Surely it is in the WSM somewhere.
The adjustment interval for Kubota seems to be 800 hours.
That would be listed in your Operators Manual under maintenance schedule.
The procedure would be under engine,perhaps cylinder head?

Good Luck!

Thanks for the lead. Found the 800 hour item (now due) which even listed the page for the procedure. I must have been really tired that day.

 

[joea99]

Giving it a try now. Figured I would find the "timing mark" first, but peering through the inspection window I do not see the mark the WSM calls out.

No doubt I will figure it out, once I remove the valve cover anyway, but while doing it I was struck by how easy it is to turn the engine over using just a combination wrench, with nothing else removed.

Even gas engines give me more fight, due to compression. Why?

BTW, the crank nut is some odd size. 24mm is quite loose, but gets it done, 22 mm is too small.

 

[rScotty]

On any cylinder, and any engine:
Turn the crank in the direction of rotation.
You want to set the valve lash when the clearance is at the maximum & avoid camshaft overlap.

Max rocker clearance for the intake valve happens when the exhaust valve for that cylinder is just opening.
Max rocker clearance for the exhaust valve happens when the intake valve for that clinder is just closing.

If I measure that the adjustment is within a thou or two on a typical .008" clearance I tend to just leave it alone.
But that's a personal thing.
rScotty

 

[5030]

I always leave overhead adjustments to my dealer's tech. On my Kubota engines, there are 3 valves per cylinder with a bridge and it requires a special tool to adjust them that I don't have anyway. The timing and adjustment marks will come into view through the inspection cover (removed) as you rotate the engine and unlike a gas motor, a diesel 'builds compression when rotating' so turning it over slowly, you won't 'feel' compression like a gas motor.

 

[joea99]

On any cylinder, and any engine:
Turn the crank in the direction of rotation.
You want to set the valve lash when the clearance is at the maximum & avoid camshaft overlap.

Max rocker clearance for the intake valve happens when the exhaust valve for that cylinder is just opening.
Max rocker clearance for the exhaust valve happens when the intake valve for that clinder is just closing.

If I measure that the adjustment is within a thou or two on a typical .008" clearance I tend to just leave it alone.
But that's a personal thing.
rScotty

One of the problems was that the WSM graphic for the procedure seems to have confused me. I took the arrow pointing to "gear case" to mean the transmission, but the layout of the valve train seemed wrong.

Took my aging brain, perhaps (more) addled by the heat, a couple "thinks" to realize it meant the "gear case" for the camshaft drive.

After that it was almost like I knew what I was doing. Running fine now.

 

[joea99]

I always leave overhead adjustments to my dealer's tech. On my Kubota engines, there are 3 valves per cylinder with a bridge and it requires a special tool to adjust them that I don't have anyway. The timing and adjustment marks will come into view through the inspection cover (removed) as you rotate the engine and unlike a gas motor, a diesel 'builds compression when rotating' so turning it over slowly, you won't 'feel' compression like a gas motor.

Only two per cylinder here and simple jam nuts.

I don't have a trailer and the nearest dealer is some 40 miles away. I would not trust them to wash the machine let along service it.

My last diesel valve adjustment was on a Peugeot 504 decades ago. How many decades, I don't recall. Or choose not to. I think it gave me more fight, but I could easily be wrong.

Job's done now and running fine.

 

[orezok]

Yesterday I did the valve adjustment on my B7800. All of them were .001 to .002 tight. The biggest issue is that there are 3 unidentified timing marks on the flywheel. The WSM does not tell what each represents.

I also checked the injection pump timing section and it doesn’t identify either.

I used the center one as it seemed to make no difference.

 

[joea99]

Yesterday I did the valve adjustment on my B7800. All of them were .001 to .002 tight. The biggest issue is that there are 3 unidentified timing marks on the flywheel. The WSM does not tell what each represents.

I also checked the injection pump timing section and it doesn’t identify either.

I used the center one as it seemed to make no difference.

I had the same issue. Also, there was no reference mark that I could see, to line them up against.

After some deliberation I chose the "third one" with as the WSM drawing seemed to show the first two as being 10 and 20 degrees BTDC. Did not seem to make much difference to the valve lash.

in the end So I "eyeballed" it with one of the bolt heads positioned as shown in the WSM photo as an additional reference. Seems close enough.