George - the abandoned 520-h

[darren 49]

I was asked recently if I would give a home to 'George' whose owner had died several years ago and had been left outside to the elements ever since. I figured a 520-h would make a good stablemate for my 312-8 which as my only tractor, gets no rest. I set out with a trailer to pick him up. It's a 1992 vintage and had 452 hours on it when it was last used a couple of years ago.

 

It's pretty sad to see a decent machine like this left to rot. I suspect it orignally had an ignition issue as one of the coil leads was off and a spark plug missing. The owners daughter told me it'd had a fuel pump problem in the past which they'd bodged a fix for. It's going to get a full strip and rebuild. Things are pretty bad on the surface but underneath, everything's solid. Here are some pictures after I got it back. I couldn't wait to get started so pulled the seat and fender before digging the camera out!

 

 

Bad points seem to be;

engine issues - missing a front spark plug and the air filter won't have done the block any favours whilst it stood outside; the engine can't be turned

rectifier shows evidence of heat on one of the terminals

lift arm seized

brake pedal seized

both rear tyres perished

seat soaked/rusted/perished

front hitch bent where the previous owner tried to move the tractor using a long pry-bar (!)

wiring for fuel tank shorted/perished

no fuel line

trans shifter seized

 

Lots of PlusGas (the UK equivalent of PB Blaster) resulted in sorting out the lift arm, brake pedal and trans shifter arm. I think they were just the result of a small amount of water ingress. I haven't had to resort to anything more powerful yet!

 

Using the front hitch as a leverage point was not a great idea. The hitch wouldn't even move;

so I stripped down the front end and was able to get a bar in to gently bend it back to straight.

 

The rest of the tractor seems very good.  I'll finish taking it apart though, clean it all up and get it back together using new hardware where possible.

 

Suprisingly, the coil seems to test good. I was sure it'd be u/s as it seems to be a weak point on the Onans.

 

Turning my attention to the engine, I found the valves looking like this;

 

and so with some interest popped off the heads to find they were now a sandpit;

 

and looked at the internals;

 

It seems water has occasionally trickled through the carb (I've ordered a replacement for this as I'm not sure how salvagable that is..), through the inlet valves and then drained past the pistons into the sump, were it's made a lovely mayonnaise.

 

I was suspecting something along these lines although I must admit i was hoping it wasn't as bad as this.. To think this could probably have been avoided by covering up the tractor (or at least by refitting the air filter!)

 

The silt build up appears to have reduced the damage to the bores somewhat but the pistons are still seized, as is one of the inlet valves I think. I'll remove the valves and then see if I can shift the pistons with a diesel bath and giving them a whack. I don't hold up too much hope though and will have a feeling I'm going to need to put up a plea in the wanted section for a block/pistons.

 

More to come as I make progress!

 

 

[cheesegrader 434]

I feel much better about the problems with my '94 520 after seeing what you are up against!

Good luck with that engine.  I hope at least the block can be saved.

[Desko 636]

Minor problems lol. But on a serious note it is truly a shame to have let a artwork of a tractor sit out but I have high hopes that you will fix it. Hope the block is still good

[darren 49]

Thanks both   I've got my fingers crossed.. Cheesegrader, I was sorry to hear you've been blighted by the 520 electrical gremlins. They often seem to be a weak point on the model from what I've read. I'll be paying attention to this one when I put it all back

[AMC RULES 37,251]

I like it...  

lot's of attitude, and patina in spades.  

Hoping you git-r-done.      

[darren 49]

Thanks Craig   I popped out again tonight after my better half went up for the night, and spent a productive hour getting the valves out and making some progress!

 

Sometimes I get the feeling that what I'm working on is co-operative and sometimes it's completely un-co-operative   Well, George seems to be doing is best to be saved. I managed to get the valves out: the exhausts came out no problem, the inlets came out after a little bit of soaking and by expanding the adjusters to help push them the first few mm. Here they are:

I'll get them cleaned up and check they're okay but they seem to be fine.

Suprisingly, now the valves are out, i've got about 75 degrees of movement on the crank and about an inch of travel on the pistons. Woo-hoo! I took a little bit of video of it;

http://youtu.be/JefWXvf-BAY

It's better than I could have hoped; a huge relief. Now I have the following problems and am looking for any suggestions on how best to tackle them;

 

In order to get the pistons out, I need to clean the crud out of the top of the bores. See here:

 

I'm not sure how best to do it. A honing tool maybe? perhaps with some kind of carb cleaner/diesel/rust-dissolver? I wondered about very carefully and gently using some 1000 grit or something but I think a honer might be more consistent. If I can smooth out the bores at the top a little, I think I'll have full movement and should be able to take everything apart. All suggestions gratefully received!

(I should be able to check everything with a leakdown test afterwards. If I'm really lucky, it may only need new rings)

 

Second bit of advice needed: at the end of the video clip is the drive pulley. I'm struggling to get this off at the moment, so before I up the brute force involved I wanted to check whether I'm right in thinking it's just the two grub screws at 90 deg to each other (and keyway) holding it in place? I've backed the grubscrews out and tried gear puller on it but it's not budging yet and I'm concerned that if I up the force on the puller I'm likely to break the pulley. If there's nothing else holding it on to the crank I'll try soaking it some more and leaving it under tension for a while. I couldn't see anything else in the IPL for the tractor.

Edited August 5, 2014 by darren

[Wishin4a416 2,323]

You have a nice machine there to restore. Best of luck with the project.

[Desko 636]

Just do a little with the hone just clean it up enough to get them out and then home it out all the way to clean up the bore and while you waiting spray the cylinder with atf diesel mix that should free it all the way up.

[Tankman 3,525]

I've never tried but, heard of a motor head who used 1" steel plate to move a piston(s).

 

The plate was drilled to match the head mounting, bolted to the block.

A grease fitting was also installed in the plate, top, center of cylinder.

After mounting the plate, the cylinder was pumped full of grease.

 

Daily, the motor head, grease gun, would add some grease to the bore.

 

He swore, "It works."      

[darren 49]

Thanks Tank, Desko and Tankman. I'm going to pop out tomorrow and pick up a honing tool. I'll let you know how I get on. I think that once the bores are cleaned up, the pistons will be able to reach their full travel. Very exciting!

[motox25 36]

It's great to see abandoned horses like that one restored. I'm all for saving that onan, great engines and you can't beat the power and sound of them. Keep us updated and post lots of pics!

[darren 49]

Thanks Motox, your restoration pictures have been very motivating. If mine turns out half as well as yours, I'll be happy!

[Martin 2,133]

I think that engine is definitely worth a try. I never got pics when I first got the heads off, but my P216 in my latest build had 2 stuck pistons and a couple stuck valves. Eventually got the engine rotating and cleaned up the bores good enough to make it run without pulling pistons etc. it's now one of my best running engines and I'm so happy I decided to get it working and not part it out. The bores have slight rust damage, but it doesn't smoke and has good compression on both cylinders. While mine didn't have a bunch of crap in the bores like yours, it was sitting for a while with no plugs, carb and manifolds, had plenty of water in it and more than enough corrosion......

Edited August 6, 2014 by Martin

[Desko 636]

Can't wait to see this restoration take place.

[546cowboy 302]

It's just a shame to see such a magnificent piece of machinery in that condition. Glad to see it in the hands of a Wheel Horse lover. I know it will respond and b the machine it was meant to be.

[darren 49]

Thanks guys, the words of encouragement really help! It's great to hear of your success Martin, I'll see how I go. I've had to mail order a honing tool as the local car factors around here don't have any (!)

 

In the meantime I'm struggling to get the pulley and the flywheel off but I'll keep at it. The rest of the tractor is apart and now being stripped of paint and rust. More photos and progress to come

Edited August 7, 2014 by darren

[meadowfield 2,932]

Rough, but still a nice find....

Good luck with the resto :D

[can whlvr 994]

on any kohler(I know your workin on an onan)its only the grub screws,so keep soaking her,maybe a little heat,but not too much,good luck

[darren 49]

Thanks Mark, thanks Don

 

I didn't have time to post last night but after cleaning up the top of the bores a bit, I found I was getting more and more rotation with the engine sitting on the flywheel and swinging the block left and right. After about a minute, the pistons had full travel:

http://youtu.be/-Aj7U0lwtww

 

Anyway, they popped out with no problem and look to be great; there's no scoring, no witness marks on the bearings. Even the rings seem good.

 

With the pistons removed, the crank and cam can be spun with no effort and continue to spin freely

http://youtu.be/_YqIsiO9WSE

 

I'll hone the bores and refit everything along with a better set of valves and see what a leakdown test shows.

 

The rest of the tractor is now in it's component parts and they're getting sanded. More pics to follow!

[Desko 636]

Glad to see you got it to make a full revolution and got the pistons out and that all is in good shape you have been lucky with this engine lets keep it up :)

Edited August 8, 2014 by Desko

[darren 49]

I didn't get out to the garage until the children were asleep, so the angle and die grinders were off-limits so instead I looked at the fuel pump and the wiring loom because I'd noticed a few issues on some of the cables at the rear.

 

All connectors seem fine but I'll give everything a good go-through with contact cleaner and reassemble with dielectric grease. Switches all test fine but I need to source a couple of instrument bulbs.

Here's the issue with the rear harness;

 

It looks as though the lighting circuit may have shorted or overheated at some point and the resultant heat damaged the parking brake and fuel sender circuits which also show insulation damage and some corrosion to the exposed section. It's all localised around the same point so I'll chop out the bad sections out and replace them.

 

As for the fuel pump:

None of that white stuff should be in there. It's a spiders nest.

 

 

After a bit of scraping out and a soak it looks more like this:

 

All the diaphragms seem to be supple so I think once it's reassembled it should be fine.

 

On to the chassis and bodywork tomorrow

Edited August 8, 2014 by darren

[cheesegrader 434]

Darren,

 

Now things are starting to look familiar!

My instrument bulbs were replaced with Sylvania A51 bulbs.

Look at your light switch to see if it has been replaced.

Mine was a 3 amp non-weather rated appliance switch.

I had the same problem with burnt wires at multiple sites (as well as a burnt switch, burnt bulbs, and burnt tail light sockets!)

The wires at the base of the fuse box were all brittle.  The box was replaced with three individual fuse holders, and so far, everything ELECTRICAL is working.

Good luck.

Nothing fouls my mood faster than electrical Gremlins!

[darren 49]

I've gone out and taken a second look to confirm: I think mine was a simple abrasion: The switch and bulbs are original and the brittleness caused by the heat damage to the wires where they've shorted only extends about 15cm from the source. Thankfully, the fusebox achilles heel seems in good shape, as does the rest of the wiring.

 

The transmission is in great shape. I was going to degrease and clean the casing, then just shoot it over with some Wheelhorse red. Should this be okay? I'm pretty new to the painting part of things. It's going to be a working machine rather than a show-horse.

PS - Get a load of that garage carpet..

 

On that note, I'm unsure how best to tackle the hood and fender - Because they've got more layers of paint and the decals, my sanding disc isn't making so much of an impact. Polycarbide wheel seems to work but the working strip is only about 2cm wide   It is more a case of faded paint than rusty steel. Should I look to use a paintstripper on them first, or just key what's there and shoot over the lot with primer and then paint? I'm not averse to taking the whole lot back to bare metal, but I'm going to need a more effective method to get there!

 

I have made some progress with the muffler and shield however. small steps!

Edited August 10, 2014 by darren

[km3h 543]

I used a paint stripper and it worked well. Don't get it on your skin. Burns like the devil. This is what I started with.

Half way there.

All gone

Finished Painting

What I used

I several different sizes of putty knives as scrappers. The important thing about using them is to make the surface edge is flat. What I did was use a bastard file and stood the knife straight up and sharpen the edge frequently. You don't want a cutting edge. It should be square and flat.

Like this

that was the first time I tried anything like this. Like you I used a sander at first but it just did not seem like the best way to do it. I took the entire tractor down to bare metal. You paint this on with a brush and watch it bubble the paint. They you just scrape it off with the putty knife.

Of course I did sand down the rust and filled it with Bondo.

Nick

[546cowboy 302]

I always use stripper myself and it takes a lot less time and elbow grease that way and if you have a pressure washer, it will take most of the paint off.  After I get it down like you did I usually sand blast that rust or just spray it with rust converter and primer before I paint it. I guess you could use some kind of acid to remove the rust or maybe toilet bowl cleaner. I can hear the laughter now but have you ever tried it? As far as scrapers are concerned, I bought a set of plastic scrapers at HF a while back just for that purpose. They won't scratch the metal.