Timing Window

[bill18163]

I have a L3940HST. I'm working on the 800 hour maintenance which includes checking the engine valve clearance. I have the fuel tank off and I'm ready to remove the valve cover on top of the engine. I decided to quit for the day but then started to look for the timing window. It has to be in the flywheel or clutch housing but for the life of me I can't find it. Can somebody tell me where it is? What side of the tractor is it on? Thanks.

 

[BeezFun]

I don't have the same tractor, but I didn't find the timing mark that useful. My inspection hole is on the clutch housing but it was obscured by some hydraulic line or something that made it hard to see. There's only one mark for cylinder #1 TDC, and they have a goofy chart in the shop manual on how to adjust the others that made no sense to me. I ended up watching the exhaust valve closing and intake valve opening and then putting the camshaft halfway in between. I experimented with the feeler gauge and there was no difference as long as I was close to that midway point. For what it's worth, I adjusted mine at 800 hours and they were all dead on, so I could have waited a lot longer to do it.

 

[bill18163]

Is the number one cylinder at the fan end or the flywheel end of the engine? I can't find any pictures or a diagram.

 

[BeezFun]

Is the number one cylinder at the fan end or the flywheel end of the engine? I can't find any pictures or a diagram.

I went through the same thing in this thread. On my tractor it's closest to the radiator, the shop manual defines it as the cylinder closest to the gear case, but the gear case they're talking about is where the crank and camshaft gears are, which is the radiator end of the engine.

 

[bill18163]

Does anyone know the cylinder number order for the 4 cylinder engine in my L3940HST tractor? I know the first cylinder at the radiator end of the engine is the #1 cylinder but what are the designated numbers for the next three cylinders as you move in the direction of the flywheel?

 

[BeezFun]

The numbering is consecutive 1,2,3,4 starting at radiator and going back to the flywheel.
Or are you asking what the firing order is? You can watch the valves on the other cylinders and identify which one is firing to get the order.
Or the service manual is only $29.

 

[jonsstihl]

I am in the planning stages of valve clearance check myself on my L4740. shop manual doesn't mention removing the fuel tank although I can see where having a little more room would help. they do say to remove the glow plugs to help when turning the engine over.

are there any gaskets or crush washers between the glow plugs and the cylinder head.

 

[bill18163]

I am in the planning stages of valve clearance check myself on my L4740. shop manual doesn't mention removing the fuel tank although I can see where having a little more room would help. they do say to remove the glow plugs to help when turning the engine over.

are there any gaskets or crush washers between the glow plugs and the cylinder head.

jonsstihl,
I took the hood off, the fuel tank and the muffler. I don't think you could do the adjustment on the valves with the tank in the way. The glow plugs have a tapered seat. No washers or gaskets. If you are going to use the timing window to view the flywheel timing marks, the window is on the right side of the flywheel housing as you sit on the tractor. BUT if you have a front end loader you are going to have to take the loader support off on the right side because the timing window is behind the FEL support.

 

[BeezFun]

they do say to remove the glow plugs to help when turning the engine over.

I'd try to turn it over before you remove the plugs to see how hard it is. Mine was easy to turn over but my engine is smaller. It's easy to get in trouble when you take a glow plug out, they tend to get rusted in place, and the wiring can be fragile. If you break one off you're looking at a major pain.

 

[jonsstihl]

I'm also wondering how likely it is to tear the valve cover gasket.

 

[jonsstihl]

thanks for the tips. I will definitely try to turn it over by hand before fiddling with the glow plugs.

 

[Henro]

I'd try to turn it over before you remove the plugs to see how hard it is. Mine was easy to turn over but my engine is smaller. It's easy to get in trouble when you take a glow plug out, they tend to get rusted in place, and the wiring can be fragile. If you break one off you're looking at a major pain.

How do you turn the engine on your b2710 by hand. Using the fan? Like to know as my B2910 should have the valve clearance checked, but this is a question I was unsure about...

 

[BeezFun]

How do you turn the engine on your b2710 by hand. Using the fan? Like to know as my B2910 should have the valve clearance checked, but this is a question I was unsure about...

I turned the crankshaft nut, you need a 23mm socket for the crankshaft nut, I had to go out and buy that because I didn't have it, I think it's a bit unusual.

I made some videos when I adjusted my valves, take whatever is useful.
This video is the intro.
This is taking things apart.
This one and this one talk about the timing marks.
And this is the actual adjustment process.

I made a few mistakes talking on the video and never went back to do it over. The correct narration is: I watch for the intake valve to just open, that's the beginning of the intake stroke, then I watch for it to just close, that's when the piston is all the way down ending the intake stroke. I make a mark with tape on the fan belt at that point. Then I watch for the exhaust valve to just open, that's when the piston is all the way down again and the exhaust stroke is starting. TDC is halfway in between those two points and I use a piece of tape to mark the fanbelt so I can find the middle point.

 

[number two]

For anyone doing valve clearance adjustments,a set of stepped feeler gauges is very helpful!
Go-No-Go feeler gauges-look them up.

 

[bill18163]

I'm also wondering how likely it is to tear the valve cover gasket.

jonsstihl,
When I took the valve cover off of my L3940 the gasket stayed in place and didn't tear at all. But you never know what might happen. I also did the valve adjustment on my B2710 and that gasket was OK. Also I should mention that my L3940 glow plugs came out with no problem. But this was at 800 hours. An engine with more hours could potentially be a problem I guess.

 

[jonsstihl]

i'm at 800 hrs too so I'm not expecting a ton of problems I just need to find the time. I may end up waiting until winter. Too many projects right now outside while the weather is nice.

 

[Henro]

I turned the crankshaft nut, you need a 23mm socket for the crankshaft nut, I had to go out and buy that because I didn't have it, I think it's a bit unusual.

I made some videos when I adjusted my valves, take whatever is useful.
This video is the intro.
This is taking things apart.
This one and this one talk about the timing marks.
And this is the actual adjustment process.

I made a few mistakes talking on the video and never went back to do it over. The correct narration is: I watch for the intake valve to just open, that's the beginning of the intake stroke, then I watch for it to just close, that's when the piston is all the way down ending the intake stroke. I make a mark with tape on the fan belt at that point. Then I watch for the exhaust valve to just open, that's when the piston is all the way down again and the exhaust stroke is starting. TDC is halfway in between those two points and I use a piece of tape to mark the fanbelt so I can find the middle point.

Thank you for the links. VERY helpful to me personally, and should be appreciated by others in the future, if they find this thread!

 

[5030]

you are going to have to take the loader support off on the right side because the timing window is behind the FEL support.

Just had my dealer adjust the overhead on my M9 and they had to remove the right loader mount to access the window in addition to the muffler and various other stuff like the steering controller. I suggest obtaining a shop manual and you can download one in PDF version from www.kubotabooks.com for free.

 

[bill18163]

I finished the valve check on my L3940 today. All the valves were within tolerance. I didn't have to do any adjusting at all. The worst part of the job was getting everything out of the way so I could access the valves. I'm glad that this doesn't have to be done for another 800 hours.