Anyone adjust engine valve clearance on M 7040 or similar tractor?

[sixdogs]

How hard is it to adjust valve lash on an M7040 or similar tractor? I bought a new-to-me M7040 that the valve train is getting a little noisy on. The OM calls for a valve adjustment at 800 hours and, while this one only has 625 hours, I'm thinking of doing it anyway. The adjustment itself is likely easy but what about the whole job? Any surprises?

 

[RoyKing]

Valve Adjustment on a Kubota - YouTube

Not very good but looks traditional, nothing special like washer kit needed, probably just gasket

 

[big bubba]

have you done engine valve adj on 4 stroke engines before? What TDC is? Experience doing that on diesel? Am sure other members will have more specific steps/advice, but just to start the conversation. If you are new to valve adjustment in general, would advise to have someone on hand who is familiar, etc.

You don't want to mis adjust an intake or exhaust valve on any engine. diesels are noisy anyway. My M8540 (bought new) has the same amt of hrs as yours..... i don't plan to do for quite a while
other members can probably be more helpful

 

[diesel85]

I've done lots of valve adjustments on all kinds of engines. Mostly motorcycle engines. Heck, when I had my little Kawi 250R, I used to check and adjust it every year to spec.

There isn't much difference except more valves. Just follow what it states in the service manual to the T and dot your I's. Make sure you know your TDC AKA 1TC-- EXACTLY.

I believe most Kubota diesel engines will get looser and they need to be tightened.

I remember it was the reverse on my 250R it would tighten as time went on with engine use.

Also, to adjust some engines, you need to buy a valve lash shim kit. I don't think Kubota diesels have that... but always check your SM.

TIPS --

*The valve clearance must be checked and adjusted when engine is cold.

*Remove glow plugs to make turning the engine easier by hand.

*Your valve clearance shouldn't be off much. So you should be able to rotate the engine by hand and use slimmer feeler gauge until the valve doesn't have pressure, then look to see where your TDC (1TC) is. You can see how much it has either loosened or tightened by using the appropriate feel gauge. THEN see how out of spec it is, and adjust if necessary. Not all of them will need to be adjusted.

*There are usually 3 marks on the flywheel 1TC, 10 and 20. Make sure you are on the right marking 1TC at all times after rotating 360 degrees.

*The sequence of cylinder numbers is given as No.1, No.2 No.3 and No.3, etc, starting from the gear case side.

*After adjusting the valve clearance, secure the adjusting screw with the lock nut. <-- DON'T GORILLA TIGHTEN IT!

*Generally most engines intake and exhaust valves take the same measurement. However, double check your SM! DON'T ASSUME!

When I did my BX2200 with the D905, it was a hair loose (like 0.002") on cylinders 1 and 3 to my likening (made up my mind and went to 0.006", right in the middle of the SM spec). So I tightened it up to spec to the SM.

Then the most important thing -- go through and DOUBLE CHECK! Even TRIPLE CHECK. Even leave the shop and come back an hour later and check again before putting valve cover back on.

Likely you won't mess anything up, but still. It's an expensive engine.

Again, I only provided advise -- always consult your tractor engine's service manual...

 

[big bubba]

good detailed advice above. still suggest having an experienced friend/mechanic on hand to verify if no prior experience

*Generally most engines intake and exhaust valves take the same measurement. However, double check your SM! DON'T ASSUME! diesel 85

not necessarily true... my experience is that exhaust clearances are generally slightly more than intake. but maybe i'm old school on that, anyway, devil's in the details best regards bb

 

[sixdogs]

Good advice here. I'm an old school guy that did valve lash adj back in the '60's with the engine running. Either that or roll the engine and do them one at a time on a cold engine. It worked then but I wonder if a diesel today might be more than I should do. It wouldn't cost that much to have a shop do it so that's what I'm debating now.

 

[big bubba]

no problem man. given your experience, should be cakewalk. just get specs & engine temp for adj. my advice on that would be when you can comfortably touch rocker arm, etc. plus cover gasket, you know that already happy holidays

 

[diesel85]

Sixdogs, nothing much has changed since the 60's in terms of valve lash adjustment procedures.

I would just roll the engine by hand and follow the clearances outlined in your engines service manual.

I doubt you'll have any issues.

You may even run into a surprise -- they don't need adjustment. Technically at 800 hours on my little D905, I really didn't need to adjust it. But I did it because it was already open, and I had my feeler gauges in hand... so why not.

 

[sixdogs]

Diesel85--So, rather than finding TDC and then going a given number of degrees off, l can do what I used to do? That is, roll the engine slightly until I get the widest gap and then adjust back to spec? I felt that method gave the most accurate adjustment. Can I even turn a diesel by hand, maybe by tuning the fan blade?

 

[oosik]

Man - this is the doorway into a very dark, black room for me. And diesel85 didn't need to remind - mine, like sixdogs, is a very expensive engine. Kubota M6040 - same basic engine as sixdog's, M7040. H**L - I don't think there IS such as a cheap diesel engine.

Less costly, perhaps. But cheap is not a term I would use when speaking of four cylinder diesel engines.

Besides, when it comes to engines & hydraulics - there is an oft remembered phrase that fits my situation well. " A man has GOT to know his limitations"