Here's what she looks like and what she sounds like.

https://youtube.com/shorts/HUhlOEME8ww" rel="nofollow - https://youtube.com/shorts/HUhlOEME8ww

So now my question is, what should we be focusing on first to get repaired?
We looked at prices for newer tractors and it's out of our budget, so we decided instead to spend some money on repairs for her, which will be a lot lower than buying a newer used tractor. We do use the tractor for farm work, as we run a marketgarden operation, so it is crucial that we have her operational and well maintained.

Up until now we just felt like we didn't know enough about engines to properly work on her, but lot's of research and watching other people work on engines has made us feel like we can probably do some of the work ourselves. So this coming winter we are hoping to get her in the barn and have some repairs started.

So again, where do we start ? We feel like the best would be to replace the electrical wiring and get the water tamperature gauge working again and degrease the engine to find the source of the oil leaking and coolant leaking.

You can use the online parts books at  https://parts.agcocorp.com/" rel="nofollow - https://parts.agcocorp.com/  

At the top right of the page, you can change the United States to Canada and change the language if you chose.  Click Search by Parts Book and type 170 in the new search box that will open.  Check the AGCO Allis box on the left to reduce the list.  You will find 170 / 175 Tractor in the list.

We are up in Manitoba, close to the big lakes.

I have found 2 different gaskets, cork and rubber. Is the one better than the other? 
Some of the rubber ones also come with rubber washers for the studs it seems. Does the rubber one need extra sealant as well or is that mostly for the cork versions?
When you say weatherstrip adhesive, any particular brand or product you'd recommend? The RTV I have found. I checked and it looks like there's currently a cork one on the tractor, could be one of the culprits of all the goo on the block indeed along with a couple of other factors. Feels like making a bit of progress figuring things out.
Thanks for the help, very much beginner level when it comes to bigger engines. I have repaired some smaller engines with great success and I do enjoy tinkering. 

I also stripped the entire wiring harness out of it. I will attempt rebuilding the damaged wires and maybe salvaging the -still-good- wires, but honestly, it's looking like 50 years worth of splices and connectors. Not sure if those gauges will still be good.. they're looking pretty rough. Is there a way to test those with a multimeter of sorts?
Right now nothing was working, except for a jerry rigged ignition key with marine parts and dishwasher switches.

I'm also working on taking the radiator out to clean the fins, they look pretty gunked up.
Looks like a birdsnest underneath the radiator too. Not sure what that is about just yet.. Ah well, I did not expect this project would be so extensive. I have 3 months until spring, gotta get her cleaned up, patched up, repaired and running out the doors by then. Definitely worth learning and improving on this beautiful machine.
Thanks for following! Merry Christmas folks

* reinstalled coolant cleanout plug at the back top of the block that was leaking previously

* removed valve cover, adjusted valve lash and replaced valve cover gasket with cork gasket

* changed oil, new oil filter

* rebuilt fuel lines with new lines, new fuel filter, cleaned out gas tank and inspected fuel level sender (might still be good, not sure yet until tractor can run)

* new alternator 10 si with 3 wires came in, still waiting on internally regulated 12v ignition coil.

* got new spark plugs

* currently working on the electrical wiring, crimping, soldering, etc.

She's almost ready to see if we can start her up again, still waiting on the coil.
Cleaned out the air filter, but it's so nasty that might need to be replaced, still need to grab water temperature gauge, potential sending unit, oil pressure gauge, volt gauge to replace ammeter, hydraulic fluid and filter and bits and bobs of electrical parts.

The air filter housing does not have a cup to cover the end of it, i take it this is important ?
Where do you ground the alternator? any bolt will do ?

Do the gauges have a seperate ground wire to the frame or do they just ground to the frame by the bolts that hold them in place ? The old gauges were all metal so I assume they just grounded themselves, some newer gauges seem painted or even plastic.

Cheers for stopping in, it's been super cool to work on this beautiful maching and have been eductating and learning alot. Hoping to be able to keep the tractor in better shape for years to come by doing this.

If you need a new wiring system I build new systems for the AC Tractors. We offer one for the 170/175 Gasser.  Visit our website and check it out. I build the systems as the orders come in. Our front wiring kit P/N is 1503-12A. Color coded the same as OEM. Much heavier circuitry than OEM and updated connectors.

Steve@B&B

bb-customcircuits.com

The older plugs Acdelco r43ts that I pulled out of her, didn't seem to be right for this tractor, but they weren't fouled with oil, just a bit sooty but not too bad.

ElementalEarth wrote: Cleaned out the air filter, but it's so nasty that might need to be replaced...

That engine needs to be warmed up fully and worked hard, but first, do whatever is needed to ensure a properly functioning air cleaner. Then you will be able to get a better idea as to what you need for spark plugs (heat range, etc.).

As Dr. Allis pointed out above, the plugs need to be LONG reach; if short reach plugs were used then the threads are contaminated with carbon deposits and need to be cleaned out with an appropriate tap to prevent further damage.

Shoot, are you telling me the Autolites 405  are no good? Honestly I don't know the difference between long and short reach, but I guess I could find some ACdelco R45XLS somewhere online. 
I got the autolites from Napa, the guy seemed to believe those would be good.

Or did you mean because the wrong plugs were used previously in the tractor (acdelcor43ts), they are a shorter reach and now the threads in the engine block are compromised making fitting a proper spark plug Autolite 405 I assume, more difficult and I need to clean the spark plug holes first like you said with a tap ?
Sorry to have to ask all these detailed questions, feeling pretty bummed to be honest about this issue.

The plug you want has a threaded portion about 3/4 in. long. I've modified an old spark plug with the long threaded section by grinding three or four grooves down the threaded length an used it like a tap to clean the carbon buildup out of the threads.  Or you could buy a tap as pictured. 

No, you shouldn't need to pull the head.

I'm glad you guys caught this, it makes sense now why the new plugs didn't want to thread in. The lower portion of the spark plug well seems caked up with deposits.
I'll have to go and purchase a thread chaser to clean it out as best as I can.

What I don't understand is why would anyone want to put the wrong plugs in an engine?
I'm undoing what looks like years of neglect and abuse, it's pretty sad. We've only been the owners of this tractor for a few years.
Is there any further damage done by running the wrong plugs ?

I laid them side by side to fully understand the significance of what you were telling me, I had no idea you could even run an engine with the wrong plugs!

Probably not.

With the spark gap hidden up inside the spark plug chamber it might make it more difficult to start the engine.

steve(ill) wrote: yes... your thread chaser or tap should clean up everything... The plugs screwed OUT, so you should be able to get the chaser back in.. OK.

Yup.

Put some grease on the tap to catch the carbon gunk, don't try to go all the way in with one pass; back it out and clean the tap, then go a little further each time. You will get a feel for it.

DrAllis wrote: R-43-T plugs don't even have a GASKET on them !!! They are a tapered seat sealing type plug !!! which damages the threads in the cylinder head.

Good catch!

I didn't look at the photo very carefully; apparently the culprit did not care enough to look closely either.

You may be right, I had no idea due to my lack of experience, but listening to some videos from other engines, it does sound like it could be misfiring. 
There are flames coming out of the exhaust sometimes and the manifold looks "wet" where the carburetor bolts on to it, not sure what to think of that. 
How to resolve this issue, just reading a bit on these forums it sounds like it could be carburetor related, timing, or even valves/something more internal.

I have the carburetor set out at 1 turn outward on the idle screw up top of the carb and the lower main jet screw at 2 turns outward, following a zenith carb rebuild video.

No clue about timing or what to even look for. Again, most of this stuff is all new to me, my experience comes from getting old lawnmowers running again, this is somewhat different.

I can make another video yes, with the throttle open all the way.

A weak battery is very tough on a starter. Starting with a booster/charger is, too. You should get a good battery ASAP.

If you run it very long with a leak between the head and exhaust manifold, it will eventually pit the head. At the very least, you should remove the manifold and try to true it back to as flat as possible and install new manifold gaskets. They need to be retorqued after every heat cycle, until they quit turning.

I'm also noticing oozing of fluid out of the head gasket I believe, looks like could be coolant because it has a slight green tint to it ? I could be wrong.
I guess that means at some point I'll have to replace that aswell.. 
It seems just very minimal seepage towards the front corner near the radiator and cylinder #1.

As far as the firing or misfiring for that matter, I was able to get her running again with our truck's battery that has a bit better reliability.
I made a video going from low rpm -> high rpm -> low rpm

https://www.youtube.com/watch?v=6fiuTr41VO4" rel="nofollow - https://www.youtube.com/watch?v=6fiuTr41VO4

Chances are good that you will have to replace one, or more, of the studs. YOU DO NOT WANT TO BREAK THESE STUDS OFF IN THE HEAD!!! At least two (it's been a long time) of the studs thread into the water jacket, so you need to put some sort of sealant on those studs, to avoid leaks.

When you are ready to install the gaskets, they are all individual. You need to use something to hold them in place. I, personally, use a small dab of grease to stick them to the manifold.

When you start tightening, start in the middle (like you would when tightening head bolts). Very lightly snug the nuts and continue gradually working outward. Repeat this several times, tightening slightly and evenly every time. I can't remember the proper torque but be very careful on the ends of the manifold. It is very easy to break the end flanges off.

As I said earlier, keep retorquing the bolts after every run cycle until they don't turn anymore. (This will take several run cycles.)

Good luck!

Oh dear, seems not the greatest of jobs. I suppose filling those millimeter gaps up with some exhaust caulk won't do right? Probably only temporary at best, I get that.

A little thrown off by what you said about the bolts breaking. May need to do some research first then, those nuts are probably on there so tight and rusted, I do have a small torch to heat them if needed, could maybe apply some sort of liquid wrench to loosen it up a bit. I'll start watching videos and come back with questions here, which I surely will have haha. 

I got some gauges and wiring to do for now, I got about a month left to finish the work on the tractor, before the busy growing season starts. Hoping to get as much done on it as I can! Thanks for the help.

Here's some pics of the manifold and mating surface

Personally, I've had good luck with a product recommended by my local auto parts store (I'm in Florida for another couple weeks, so I can't tell you what it is - old man's memory...). Some of the old guys used pepper or ginger with some success.

I would pull off the valve cover and check everything for tightness (torque) and see if there is an obvious problem. If nothing, I would start it up and get it up to temperature a couple times and recheck the head torque. If I found nothing, I would try some stop-leak.

That's some good advice and pretty doable. Just pulling the valve cover I can access those bolts or does it involve removal of the rocker assembly aswell ?

Here's a test fitment I did after 2 hours of grinding, not the final result as I spent more time afterwards perfecting it a bit further, but you can clearly see the huge difference this made in having a better fit. I'm glad this worked out, the forums helped figure things out on what to do, as well as a handy guide on youtube.

https://www.youtube.com/watch?v=gxxyhvoMve0&t=2s" rel="nofollow - https://www.youtube.com/watch?v=gxxyhvoMve0&t=2s

Now for the other news... my block is seeping coolant, so a forum member above, thanks WF-owner, mentioned tightening the bolts on the head..
So I took the valve cover off and noticed;

1. the bolts are under the rocker arm, tightening them will mean removal of said rocker arm

2. at the surface there is white milky oil.

And then the panic set in, but I think I got it figured out why that is..
Something called condensation, not running the engine for very long and the fact that it's -10*c in my barn, from running a search on the internet I can conclude this is a natural occurring phenomenon when an engine is not able to burn off vapours because it didn't get hot enough by running long. I've only run it for 5-10mins tops in a freezing barn.
There was even frost on the inside of the valve cover, by the air cleaner cap.
I checked the oil dipstick, it looks normal color oil. The only area the milky oil occurred really is by the air cleaner pipe of the valve cover, definitely leading me to believe this is natural condensation happening due to rapid cooling of vapours not fully burned off.

Opinions welcome, this is all very new to me, luckily there is so much information online about engines and symptons and all of that.
I'm not ruling out a coolant leak, but there is anti-freeze in the coolant, so that should'nt freeze right? And the frost on the valve cover had a clear color, not green, which truely leads me to believe this is condensation only.

Anyways here's a picture.

PS; how do I remove the rocker arm assembly? for some reason I'm worried springs popping around and valves dropping down in the engine, lol!

I applaud your tenacity and resourcefulness in hand-fitting that manifold! Most of us would say that it should go to a machine shop but you got'er done!

On some engines you can use a crowfoot socket adapter so as to not need to remove the rocker shaft.

The valves won't fall into the engine or go SPROINGGGG!!! if you do remove the rocker shaft (it just unbolts).Do re-adjust the valves regardless.

I, personally, remove the rocker arm. It takes minutes and I feel I get a more accurate torque with a regular socket.

Edit; beginner's mistake I suppose, I turned the engine over and realized pressure was relieved on said pushrods holding the rocker arm up. I suppose I needed to alternate tightening bolts down as I slowly turn over the engine and release valves?
I could not find the proper procedure in the manual anywhere unfortunately,
I don't think I did any major damage, maybe at the worst I stripped the stud a bit..

Am I able to pull out that stud from the top of the engine and replace it ?

Is the stripped nut on a stud like the one in this photo?

If so, you should be able to put two nuts together on top and jam them tight, then unscrew the stud.

That's what I was thinking as well, I don't know how much clearance the valve cover has underneath the cover, but worth finding out indeed!

Still waiting on the stud for the manifold and the nuts, still some electrical wiring to do for the lights. Excited to get it going again, spring is on the horizon, the canadian geese are returning, they know best.
Thanks again for all the time and replies on here. Stay tuned!

Oil pressure is around 30psi. I installed a T fitting so I could have the warning light on the dash still.

For some reason my temp gauge stopped working (its new). It does read around 100 when I turn on ignition. My guess is the sending unit is sitting in an air bubble if that's possible, because I had to drain the coolant to do the head bolts tightening, so it's possible that the liquid is just not reaching to the sender, may need to drain the air a bit by cracking the plug open for the sending unit. It was working before as I noticed running the tractor for 5mins, temp got to 160.

Swapped out a couple of broken headlights with new LED's, the difference is astounding haha.. I may need to replace all of them just to be on the same kind of light output, right now it just looks funny, but hey, it ain't broke..

Also cleaned up the dash, sprayed it with a rustoleum, rust color, to match the original rust color scheme that was throughout the dash. all new gauges, except for the Tachometer, which is not connected and probably never will as I switched to a newer style alternator with no tach hookup. But that's alright, I might get an aftermarket one at some point.. 



So what's left to do now.. basically tying up loose ends. Fluids will need to be changed still. One of the pistons on the loader still bent.
Will keep a better eye on overall health now that I have more experience and time with her. Also, these forums and the speed of replies of folks on here has been extrordinary helpful with diagnosing and progressing.
I know that I may not be able to contribute as much in terms of responding to other posts, as I generally lack experience to be of much help.. But I hope that if someone has a similar problem with their tractor model 170, they might find some information in this lengthy well detailed thread by using the search feature.

As far as engine health, she sounds much better, I'm not sure if she is misfiring or not as Dr. Allis mentioned. I did check to see if the distributor was timed to the center mark in the flywheel and indeed it is. However I don't have a timing light or the knowledge to time it to the F25 mark. That might be something for next winter.

Overall the rust on the body isn't too bad, but it would be great to just kind of freshen up the paint in the near future, especially since she lives mostly outside under cover of a tarp.

Looking forward to the growing season ahead of us and how well she will run. I'm glad I took the time to learn and invest in this great tool. I have not counted the hours, but it's been many many hours in a cold barn. Luckily, it seems this was the best winter in terms of warmth to do this. Many days above freezing helped me progress faster.

Thanks for reading ya'll! Busy season starting very soon, so this might be the last update in a while. 
Let me know what you think, if you made it this far haha.
Advice, tips, cheers! Hope you all tractor on.

New temp gauge and old sender?  May not be the correct ohms between the two...

Might find the same for fuel gauge too unless you have the sender that is compatible to the gauge.