[Kenc]

JMHO, but before starting work on the engine, contact Boomer (info in previous post) regarding a replacement. He often can provide parts or a complete at good prices. 'Normal' parts sources can make an Onan project difficult to justify.

OTOH, that is a really good machine when running. The transaxle parts are easy to find, if needed, and fairly cheap. I have some complete units that are too far away to help you. The internals are interchangeable across almost all years. The housing has some external differences but interchange. If my experience is any guide, you'll probably spend more time on correcting hydraulic leaks than anything else. The 4000's with power steering and 3 pt have a lot of connections!

 

[Eric2.0]

Eric,
I am currently in the middle of my rebuild of that same tractor mine had a destroyed rod and was running on one cylinder just got the block back from the shop and waiting on new rods and pistons to arrive if you would post some pictures of the engine before you tear into it I would like to see the throttle cable routing if possible mine had a modified throttle on it thanks and good luck with the restoration

Oh for sure, no problem. Just got it home today, popped the hood and looks like all the cable and breather stuff are all intact. I'll get you detailed pictures and video.

 

[Eric2.0]

Fin

 

[mryeti117]

That looks pretty mean with those ag tires on it

 

[Eric2.0]

That looks pretty mean with those ag tires on it

I imagine with that type of tire, this tractor did some hard duty. With 1654 hours on the meter, pretty much everything is probably wore out. It looks to be complete and decent shape frame and body wise though.

 

[a66coup289]

I imagine with that type of tire, this tractor did some hard duty. With 1654 hours on the meter, pretty much everything is probably wore out. It looks to be complete and decent shape frame and body wise though.

The engine may be gone, and other parts do loosen up over time, but the machine is not likely "wore out". The hydraulic drive system is pretty durable.

 

[Vigo]

Looks like it was owned by a DIY wrenching enthusiast at some point. You don't find Cometic stickers just all over the place, even among 'car guys'. And as a car guy putting 'the right tires' on something seems SUPER important to me even if i barely use the machine and the rubber money just ends up sitting there rotting. So who knows if it really did any work after the R1s went on. 😂

 

[Eric2.0]

Looks like it was owned by a DIY wrenching enthusiast at some point. You don't find Cometic stickers just all over the place, even among 'car guys'. And as a car guy putting 'the right tires' on something seems SUPER important to me even if i barely use the machine and the rubber money just ends up sitting there rotting. So who knows if it really did any work after the R1s went on. 😂

 

[mryeti117]

I see it has the rear hydraulics as well does it have a lift selector valve as well

 

[a66coup289]

The man I got it from was the original owner, I have the original owners manual and all that, receipts from being serviced and fixed through the years. It was mostly taken care of until the engine popped and it sat abandoned I'm the yard for a decade. The sticker was probably put on by a service mechanic advertising cometic gaskets he sells. That's my guess. The ag tires were probably put on because he pulled a tiller with it, plowed and all that. It was used more than just a lawn mower.

I was able to get the rear axle to turn free today, which is really promising. I drained and filled the engine full of fresh oil, until it poured out the fill cap on an attempt to lube an engine that has sat dead for a decade. The next nice day I get, I'm going to strip off the carb and muffler, so I can get into the valve covers to see what is going on with that broke valve. If I can fix that and get the engine to turn over, I'll go ahead and rebuild the carb and other things, see if she will start.

Pull the plugs and squirt a little oil in the cylinders and let that sit a few days

 

[Eric2.0]

Pull the plugs and squirt a little oil in the cylinders and let that sit a few days

The left side head was already loosened up when he was investigating the problem. The piston seems to be TDC on the exhaust stroke in that cylinder, because the valve is fully open. However it won't let the head sit flat on the cylinder because it hits the head when trying to put on. This tells me the valve is extended out from the seat way more than it should. The piston is TDC so hard to get oil to lube the entire length of the cylinder. I don't want to dry rub the cylinders, so I thought filling the crank case up full would get the oil in from the back side of the cylinder. I'll tip the tractor up on its side a little so oil can get down in the cylinder.

I never tried to rotate the engine yet, but it may rotate just fine. Sitting for a decade I didn't want to dry scuff the cylinders, so loading it with oil will make me more comfortable rotating it after a decade of sitting.

 

[Eric2.0]

I see it has the rear hydraulics as well does it have a lift selector valve as well

It must have controls for that someplace. I'm not sure which one it is yet. We had a snow storm today, so it was hard to see everything. I haven't gotten in the garage yet to let it thaw out and clean it. I did manage to get the axle to rotate which is a huge relief. Now I can pull it and not have a dead horse to move. It also gives me enthusiasm to keep going on this tractor.

 

[dundee222]

By whatever means get the poor girl inside where it's good and warm, even your living room if you need to! 10 years of sitting especially with a head off can and will allow water and condensation into all sorts of places, making even a good diagnosis of the internals impossible.

 

[Eric2.0]

By whatever means get the poor girl inside where it's good and warm, even your living room if you need to! 10 years of sitting especially with a head off can and will allow water and condensation into all sorts of places, making even a good diagnosis of the internals impossible.

I drained the old oil out and watched for any water or metal fragments, but found none. I got black, thick, old oil.. thankfully the Onan is a horizontal piston so less chance of water getting in. I'm working on getting it inside and warm it up now that I have the axle rolling so I can pull it.

 

[Eric2.0]

Seems to have a busted dipstick. I'll have to see if it slid down I to the crankcase now. I don't think this is the original cap either.

Where or who has one for sale? For a 4020, Onan.

 

[Eric2.0]

Here is the correct oil filter air seal:

122-0502 - GASKET - OIL FILTER SEAL

122-0502 - GASKET - OIL FILTER SEAL, onan oil filter gasket, C20577

salempwr.com

Brian

I just ordered two of them. Do you have a dipstick for a 4020, Ingersoll Onan?

 

[Eric2.0]

Some pictures of the engine bay. I wanted to get detailed cable routing pictures for someone on here, but it is freezing and snowing out. I don't do cold much anymore in my older age, lol. I'll get those detailed pictures on a better day. Until then I was excited to keep checking out this tractor. This thing still has a battery in it all hooked up with keys in the ignition, virtually untouched from the day when it quit running. I don't know why he never got it fixed back then, unless the engine is really messed up. We will find out soon.

 

[Gordy]

Eric,
I am currently in the middle of my rebuild of that same tractor mine had a destroyed rod and was running on one cylinder just got the block back from the shop and waiting on new rods and pistons to arrive if you would post some pictures of the engine before you tear into it I would like to see the throttle cable routing if possible mine had a modified throttle on it thanks and good luck with the restoration

The engine shop near me will measure the cylinder and crank jurnal, and tell you what to order. Other than that he will not touch the block until the parts arrive, so he can measure them and adjust what he does to the manufacturing variances.

Cheers,
Gordy

 

[boomers_influence]

eric 2.0
you will need a different dipstick, tube, & cap.

thank you. boomer

 

[Eric2.0]

I have the tractor inside the garage with heat on to warm up and melt the ice in the rear end housing. So far I got the axles to rotate easily, but when I grab both hubs together and spin the same way, it's still locked up. I'm hoping an overnight in the heat will melt any remaining ice that may be holding it up. I have videos to upload tomorrow when I get time. Thanks guys, I'm starting to have some fun with this project. I'm pretty sure it's in neutral, but maybe I'm missing something. Could the hydrolic axle motor be seized?