Oil pressure dropped to 10 pounds

[Larry LGT 165]

I will look at the relief valve today, it would be a easy fix! But back to the plug, would it come out and fall into the pan, or be swallowed and ground up by the engine? I could pull the pan to get it out if I had to.

New member here.... interesting read as I just spent the last couple of days pulling my B6000E / ZL600 apart for the same reason.

On the second oil change since I've owned it, only a few weeks, the plug fell out in the oil drain pan. The oil light had been flickering at low rpm.

I'm a retired diesel engine mechanic so I took it apart pretty much as a retirement project, just to have a look inside. Sure enough, there was the open hole in the center of the cam shaft.

After trying several things for a plug, I settled on a 1/4" NC bolt with the threads ground down to a slight taper. It tapped in nicely and got firm as the head reached the end of the shaft. Used the arc welder to secure it but after reading, will have to check to see if indeed there is enough clearance under the cover for that bolt head.

While there I checked the timing marks on the gears. Each was out exactly 4 teeth on the idler, but the timing would have still been correct. Can only assume the cover had been off in the past and someone lined the idler teeth up straight on, but being helical cut, they ended up 4 teeth out at each location when the gear was pushed all the way in.

Needless to say, it is now corrected.

Any hints or help you can offer while I have it apart would be greatly appreciated. Will attempt pics later, Thanks.

 

[D2Cat]

Larry, you might double check that timing. I think the engine has to turn over several times before the timing marks line up. You may have undone it!!

 

[North Idaho Wolfman]

While there I checked the timing marks on the gears. Each was out exactly 4 teeth on the idler, but the timing would have still been correct. Can only assume the cover had been off in the past and someone lined the idler teeth up straight on, but being helical cut, they ended up 4 teeth out at each location when the gear was pushed all the way in.

It probably was in time, Kubota timing gears only line up exact every 138 rotations, so if you look at it at any other time it looks like it's out of time.
So like D2Cat said, you might want to check that all marks are lined up at the same time!

 

[Daren Todd]

New member here.... interesting read as I just spent the last couple of days pulling my B6000E / ZL600 apart for the same reason.

On the second oil change since I've owned it, only a few weeks, the plug fell out in the oil drain pan. The oil light had been flickering at low rpm.

I'm a retired diesel engine mechanic so I took it apart pretty much as a retirement project, just to have a look inside. Sure enough, there was the open hole in the center of the cam shaft.

After trying several things for a plug, I settled on a 1/4" NC bolt with the threads ground down to a slight taper. It tapped in nicely and got firm as the head reached the end of the shaft. Used the arc welder to secure it but after reading, will have to check to see if indeed there is enough clearance under the cover for that bolt head.

While there I checked the timing marks on the gears. Each was out exactly 4 teeth on the idler, but the timing would have still been correct. Can only assume the cover had been off in the past and someone lined the idler teeth up straight on, but being helical cut, they ended up 4 teeth out at each location when the gear was pushed all the way in.

Needless to say, it is now corrected.

Any hints or help you can offer while I have it apart would be greatly appreciated. Will attempt pics later, Thanks.

Front main seal, the o'rings in the crank case cover, new collar and o'ring if collar is grooved from seal. New water jacket o'ring. If fan runs on its own shaft, check, replace bearings if needed while it's easy to get too

 

[Larry LGT 165]

Larry, you might double check that timing. I think the engine has to turn over several times before the timing marks line up. You may have undone it!!

Thanks D2Cat, my initial thought was it may have been done on purpose as perhaps a balancing issue but there is in fact just an idler gear no balance shaft in this engine.

Yes, 2 revolutions are necessary for the marks to line up again, but the relationship between the crankshaft, the camshaft and injection pump shaft actually did not change. What I did was slide the idler gear out, rotate it 4 teeth and slide it back in so the three sets of marks now align, instead of each being out 4 teeth.

I will try to post before and after pics of the gear train for comparison. Thanks again for the quick feed back.

 

[Larry LGT 165]

Front main seal, the o'rings in the crank case cover, new collar and o'ring if collar is grooved from seal. New water jacket o'ring. If fan runs on its own shaft, check, replace bearings if needed while it's easy to get too

Thanks Daren, the front main seal for sure. This is the old 2cyl, so I don't believe I am into coolant passages. I've not yet checked for the seal runner on the crankshaft. Wanted to see how Kubota sold the seal before I disturbed it.

Does anybody know of other sources for ZL600 gaskets etc. in Canada besides the dealer?

 

[Larry LGT 165]

It probably was in time, Kubota timing gears only line up exact every 138 rotations, so if you look at it at any other time it looks like it's out of time.
So like D2Cat said, you might want to check that all marks are lined up at the same time!

Thanks Wolfman, I had not heard this before and must be due to an odd tooth count on the idler gear. What I did observe was all three gear markings appeared to be correct, except that the idler was out 4 teeth at each location. Perhaps had I rolled it over additional times, the idler marks may have coincided on their own. Will roll it over a few times with the crank nut tomorrow and see if the idler relationship changes.

.EDIT; pics added

gear timing marks before........gear timing marks after
.

missing plug fell out of oil pan drain....bolt / plug in place with welding spatter shield
.

 

[Daren Todd]

Thanks Daren, the front main seal for sure. This is the old 2cyl, so I don't believe I am into coolant passages. I've not yet checked for the seal runner on the crankshaft. Wanted to see how Kubota sold the seal before I disturbed it.

Does anybody know of other sources for ZL600 gaskets etc. in Canada besides the dealer?

The three small o'rings in the cover were for oil passages on my L1501. It also has a water jacket built into the crank case cover to feed the engine with coolant. Had a larger o'ring to seal the water jacket where it tied to the front of the engine block.

Just something to look for. Haven't had any experience with the engine on your tractor

 

[Larry LGT 165]

The three small o'rings in the cover were for oil passages on my L1501. It also has a water jacket built into the crank case cover to feed the engine with coolant. Had a larger o'ring to seal the water jacket where it tied to the front of the engine block.

Just something to look for. Haven't had any experience with the engine on your tractor

This one, I basically bought for the experience. Farm next door had a couple back in the 80's and I always liked them.

I had watched a couple utube videos and saw the larger / later engine incorporated both the oil pump and coolant. Guess I just got lucky with this engine, simpler design.

What I do need to get apart is the governor lever on its' shaft as the o ring leaks oil there. So far the two have not wanted to come apart

Also adjusted the valves and appears the valve cover gasket may be an o ring as well.

Something I have not been able to find yet is procedure or clearance for the decompressor adjustment.

 

[Daren Todd]

This one, I basically bought for the experience. Farm next door had a couple back in the 80's and I always liked them.

I had watched a couple utube videos and saw the larger / later engine incorporated both the oil pump and coolant. Guess I just got lucky with this engine, simpler design.

What I do need to get apart is the governor lever on its' shaft as the o ring leaks oil there. So far the two have not wanted to come apart

Also adjusted the valves and appears the valve cover gasket may be an o ring as well.

Something I have not been able to find yet is procedure or clearance for the decompressor adjustment.

You can get the service manual and parts manual for your tractor here

http://www.kubotabooks.com/AutoInde...s/&AutoIndex=8fd11b4e7fe70464116abbf15227d7ba

 

[Larry LGT 165]

You can get the service manual and parts manual for your tractor here

http://www.kubotabooks.com/AutoInde...s/&AutoIndex=8fd11b4e7fe70464116abbf15227d7ba

Thanks Daren, but unfortunately the engine section is very limited in the B6000E service manual.

What I'd really like to have access to is a ZL600 engine service manual if a pdf copy is out there.

 

[shooter56]

I have not had a minute to look at the kubota, but this thread is evolving.

 

[Larry LGT 165]

I have not had a minute to look at the kubota, but this thread is evolving.

Apologies Shooter as we did kind of run over your thread. Hope life allows you the time to get to it.

In responce to Wolfmans info that the marks only line up every 138 revolutions, after almost wearing out a ratchet and my wrist, the 3 sets of timing marks will indeed coincide once again if you roll the crankshaft over enough times.

 

[shooter56]

Apologies Shooter as we did kind of run over your thread. Hope life allows you the time to get to it.

I have no problem with others on the thread, I was surprised to see it still going on.

Pat

 

[Larry LGT 165]

Just a quick update, and a little encouragement for you Shooter.

My engine is back together after also getting a valve adjust, new fuel filter and an oil change in the process. It fired right up, ran and idled great.

The oil light immediately went out upon start up and did not come back on until the engine had literally stopped turning over. Success !

Thanks for your input Gents.