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.

 

[rScotty]

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

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.
SNIP

I think that "gear case" would have fooled me as well - although old Brit motorcycles used the same notation. Along with "onside" vs "offside".

How did you decide that you were on the compression stroke as opposed to the exhaust stroke?

 

[rScotty]

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.

Leaving simple maintenance things to the dealer's tech has a problem that confounded me for years at my mechnical shop.

The problem is that in US shops, any routine maintenance is traditionally performed by the most novice mechanic. The idea being that maintence work is repetitive, boring, and there isn't really any good way for a shop to make a profit on it.
So maintenance work is used as a way for the lower wage novice to build experience.

The problem for the shop owner is in the consequences of any mistakes. The consequences are unsidedown & backwards.

What I mean is that if a master mechanic makes a mistake with a gear box reassembly it is pretty obvious, easily corrected, and no great harm done. Same for replacing a hydraulic control valve assembly. Mistakes are obvious with no lasting damage.
But if a novice makes any of several simple mistakes setting the valve lash then the consequences can cost easily cost an engine. Simply mis-threading a HST filter can cost a HST pump. And brakes jobs are a whole 'nother set of nightmares.

I end up doing the routine maintenance myself simply because it is so critical. And leave the difficult repairs to the tech.
rScotty

 

[joea99]

I think that "gear case" would have fooled me as well - although old Brit motorcycles used the same notation. Along with "onside" vs "offside".

How did you decide that you were on the compression stroke as opposed to the exhaust stroke?

After I collected my thoughts, rotated 360 and found the two valves at the "gear case" (radiator) end were "free" as were the other two that were called out to adjust.

Another 360 and, amazingly, the remaining valves were free. Just as it was written up.

 

[BeezFun]

If you look at this post I included the videos I made when I timed my engine, it's probably very similar. That nut is 23mm.

 

[5030]

I end up doing the routine maintenance myself simply because it is so critical. And leave the difficult repairs to the tech.
rScotty

Not an issue at my dealer. Guess I'm lucky. The lead tech is the only person who works on my tractors and I know him. There are no 'novice' mechanics there anyway and again, because of the double valve arrangement on both of mine and the fact it takes a special bridge too to set them, I want Dennis to set the valves. I do everything else here except that and lash adjustment on the VTE engines is at 1000 meter hours anyway. Took the last one to 1250 before I did it and Dennis told me they were still basically with in spec anyway. I attribute that to the Rotella T6 and the Archoil additive I always use.

 

[rScotty]

Not an issue at my dealer. Guess I'm lucky. The lead tech is the only person who works on my tractors and I know him. There are no 'novice' mechanics there anyway and again, because of the double valve arrangement on both of mine and the fact it takes a special bridge too to set them, I want Dennis to set the valves. I do everything else here except that and lash adjustment on the VTE engines is at 1000 meter hours anyway. Took the last one to 1250 before I did it and Dennis told me they were still basically with in spec anyway. I attribute that to the Rotella T6 and the Archoil additive I always use.

That's one way to solve that problem. The other way I've seen it done is to assign a mechanic to a customer group.
That's what I did. That way the maintenance and repairs have consistency on both sides.

Too bad about there being no novice mechanics at your dealership. I've also noticed that not having novices learning the skilled trades seems to be a common business strategy recently. Although it is a sign of the times, IMHO it doesn't make sense from a societal or demographic perspective, believing as I do that it is a responsibility of a successful business to be constantly training new personnel.
Hmmm.....that perspective probably dates me....

rScotty

 

[5030]

I believe the issue with my dealer is actually finding people to work there. They have been wanting me to come work for them part time but so far I've resisted. With gas prices what they are, I try to limit my driving as much as possible.

The dealer owner is a farmer so he understands that farming takes preciident and all his current employees are dirt farmers. In fact, Dennis who works on my tractors is a Dairyland seed dealer and he farms 450 acres too. Least he has his 2 sons to help out.

Just took my wife's Suburban into the local tire shop (they do farm tires too) and was talking to Dee, the office manager and I remarked they need to move into a bigger building with more bays or build one and she said their big issue is again, finding employees willing to work. They are so busy, you have to make an appointment for on vehicle tire work. The Burb had a TPMS sensor go out and needed one rim (aluminum) sealed. I was there promptly on my appointment. A tire shop isn't easy work by a long shot and no one today wants to work or at least do physical work.

Strange times we live in.