L345 Piston Removal

[roger23]

We are working on an L345 and would like to take the pistons out to check that the rings are still functioning well. So it looks like we have to take the sump off first (head already off). We have taken the shaft under the sump off but we still cannot manuevre the oil pan out because it is held in place by a couple of studs at the front end. Question is whether we need to split the tractor now?

 

[rbargeron]

There are 4 studs pointing forward in the front end of the oil pan. I haven't done it myself but it might be possible to tack the nuts to the studs and turn them out, allowing the pan to come off. Studs don't usually turn out hard.

edit: The parts list shows the four studs on the earlier serial# L345's. I just looked at my L345 and it has bolts there instead.

 

[007kubotaguy]

It is very easy to remove the front end. Support the tractor under the transmission. If you have front weights , remove them. It is best to remove the hood. Remove top and bottom radiator hoses,remove head lite wires, disconnect battery cable, remove the two side supports that go from dash to the radiator.disconnect tie rod from steering box.put a floor jack under the front axle, remove the bolts that attach front axle to oil pan. I think you will find a few more bolt in the front of the oil pin that will need to be removed.
Good Luck Lance

 

[roger23]

Thanks for your replies. we did try tacking the nuts to the studs but we weren't succcessful with that but it will be worth another go before we go ahead with tractor separation. Thanks much to 007kubotaguy for your instructions on removing front end. I'll let you know how we go.

 

[rbargeron]

In view of the switch to bolts it would probably be ok to weld the nuts permanently - just leave some room for the wrench. I've had several transmission case studs turn out during normal nut removal - the paint sticks better than the thread locker they use (if any). Hope it goes well - Dick B

 

[roger23]

In view of the switch to bolts it would probably be ok to weld the nuts permanently - just leave some room for the wrench. I've had several transmission case studs turn out during normal nut removal - the paint sticks better than the thread locker they use (if any). Hope it goes well - Dick B

Thanks Dick. Will try this first.

 

[roger23]

just wondering, before we go ahead with this over the weekend, do any of you know if once we get the oil pan off and are ready to remove the pistons, will they slide out quite easily or will we then be faced with removing the crankshaft as well?

 

[rbargeron]

No need to take out the crank. (impossible anyway - see below)

With the oil pan off the connecting rod caps are directly accessible. With the caps off the pistons push up and out.

The rings are fragile - it's easy to break 'em even if careful. Use pins, solvent, a proper ring spreader - work them out slowly.

Let us know what you find - good luck, Dick B.

edit: p.s. attached pic is a typical Kubota block (upside down). Notice the large holes for the crank-and-bearings assembly that slides in from the end.

 

[roger23]

Thanks. I'll let you know how we go.

 

[roger23]

We successfully split the tractor which then revealed two more hidden bolts so it would not have been possible to remove the sump without splitting the tractor first. There was also a small shield/plate on front right side that needed to be removed to reveal another bolt that needed removing.

Pistons now out, 3 in good shape, one with corroded and seized rings so we're glad we did the job.

Thanks for all your help.

 

[rbargeron]

Glad you got it apart. What were the symptoms before? Hard starting? Smoking blue? Was the engine stuck?

 

[coachgeo]

Was it piston number one that had the most issue?

 

[roger23]

The tractor wouldn't start at first so we diagnosed a hydraulic lock and managed to clear that easily. Then it would turn over but not start and there was water in oil and diesel in water. had been left in a paddock for weeks and had lost all water and compression. So we took it from there figuring there is a crack in the head probably. Valves are extremely corroded at bottoms. The shop says we need to get a new head but we are wondering if we can keep the head and just get new valves. Shop says we need new pistons as well but we are thinking we could just get new rings since this is obviously an old tractor and probably going to be sold pretty soon .... if we can get the thing running again!

 

[roger23]

Was it piston number one that had the most issue?

It was the piston closest to the back of the tractor. Is that piston number one and what is the reason that this one should have the most issues?

 

[North Idaho Wolfman]

#4 is in the rear, # 1 is in the front.

 

[rbargeron]

Hydraulic lock?? Did you find the caused of it? That answer may explain why one is worse. For example a small coolant leak into one cylinder might go undetected for a while - gradually doing serious damage. At rest the rings rust and get stuck, also corroding the walls. Any idea how long since it was last running?

Coolant leaking inside an engine can do a lot of damage if let go. By the time it no longer starts, there's damage everywhere. Apparently your shop thinks reconditioning the head will cost more than a new one.

For a temp fix, you could possibly wire brush everything clean, replace the worst valves, hone the bores and throw a set of rings at it and put it back together with a new head gasket. It might run ok with some smoke and might last a while. For $300 in parts you could see what else the machine needs before investing in a proper engine rebuild.

 

[roger23]

We are about to put new pistons back into V1501 bore/cylinder. We need specs for torque of bolts that hold con rod (connecting rod) to crankshaft. Can you help?

Also, any ideas on cleaning sludge and rust and scale in water jacket of engine block?

 

[rbargeron]

M-7 connecting rod bolts are usually listed at 19-22 ft-lb. M-8 are about 15% higher.

From your prior posts its not clear how and where the oil, fuel and cooling systems were mixing with each other. With the head gasket installed it would be good to apply low-pressure air and inspect for leaks between systems.

Clean-water flush with the thermostat removed will get the loose debris out. Isolate and flush the radiator separately. A bare block can be tank boiled but with it in the tractor flushes are the practical option.