So I did a thing... Agria 8900D

[groundcover]

Worth dropping a new engine into it ?

 

[ptsg]

Hopefully that's the extent of it.

Me too!

Since Piston hit the head and valve are you sure the crank or connecting rod are not damaged. Like you stated a whole lot of inertia to shear that flywheel key and drive that valve stem through the head, break piston skirt, etc.

There lots of signs of fretting happening between the crankshaft and the flywheel, so I suspect at one point, it ran slightly loose. That could cause most of the damage on the key.

The connecting rod is massive for the size of the engine and an initial assessment didn't looked like it was bent. Crankshaft is fine.

Worth dropping a new engine into it ?

Lombardini (part of Kohler) still produces this engine today. A new one is nearly €4,600, about what the tractor is worth when it's all fixed and in running condition. An used one is no where to be found, not even one for parts so I could snag the head.

 

[oldnslo]

Pt
Wishing you the best on getting than tractor operational again.

 

[ptsg]

Pt
Wishing you the best on getting than tractor operational again.

Thank you oldnslo! I'll need it!

I did left the head at the engine repair shop today. Interestingly enough, the guy was more worried about the hole that the valve stem poked through the head than the damage on the valve seats. He says he can handle the seats no problem.

 

[MTGreen]

Thank you oldnslo! I'll need it!

I did left the head at the engine repair shop today. Interestingly enough, the guy was more worried about the hole that the valve stem poked through the head than the damage on the valve seats. He says he can handle the seats no problem.

Is he going to Magnaflux the head to look for cracks?
I'm thinking that's a possibility with the piston hitting the head -especially considering the fractures on the piston skirt

 

[ptsg]

Is he going to Magnaflux the head to look for cracks?
I'm thinking that's a possibility with the piston hitting the head -especially considering the fractures on the piston skirt

We didn't go that far yet. Basically he was still going to see if he could fix the head. Maybe he will give me an update later in the week.

 

[ptsg]

Still no news on the head but I have been doing some more work on the tractor. Took the start apart, gave it a good cleaning and lubricated what needed lubrication and it's good to go.

Also machined a new woodruff key, technically two since I made it out of round stock. Might as well get a spare.

Had to modify the oil filter housing, because evidently they changed filter sizes between when my engine was made and now, even though this is a OEM filter. This required make an aluminium insert so the seal has a place to seal. Also, the original thread was M16x1.5 while the new one is M14x1.5. This required me to machine an new threaded insert with both threads. Of course, I could've just bought the oil filter + filter housing kit, but at this point, I'm sure you already know how cheap I am.

The air filter box also needed some work. Somehow got some rust holes on the top of the housing which is kinda weird to me. Also got a crack on the size because the hood had been hitting it for who knows how long. All fixed now, just need paint.

There was an adapter fitting between the injector line and the injector. Someone cross threaded it before, so it was a pain to remove and essentially broke the fitting in half. Had to remove the broken bit from the line by welding a washer and then a nut. Luckily it came out that way. Couldn't source a new one anyway, so I just machined one.

Today I spent some time pulling the seat out, so I could remove the top cover of the rear transmission of the tractor. I was eager to see the condition of it and why the main shifter (1st to 4th) was stuck. Turns out the shift rails were rusted and I suspect the detent springs are probably gone or very very rusty and weak. A little bit of WD-40 took care of the stuck rails. I will pull everything apart to clean it really good.

I knew there had been some water in it and it became very obvious that there would be some rust involved. On the bright side, I inspected all the gears, and everything looks nice, just a little bit of wear which is to be expected. I forgot to take pictures after I removed part of the diff lock mechanism, the rectangular plate with the shaft poking through. I would have made it easier to see the diff.

 

[MTGreen]

Nice work!
On the oil filter adapter insert it appears from the pic that you machined a smaller diameter thin ring that press fit on the OD to the ID of the cast ring boss. There is an overhang of the insert over the cast oil passages. I'm trying to understand how that is going to seal correctly and not have a seeping leak, especially when there's a possibility of that thin ring flexing from over tightening the filter with that overhang? Did you use a boring head or rotary table to cut a flat base on the casting to create a flat surface for that insert to seat up against?

Here is an idea using an o-ring to make an adapter that avoids that potential issue. It would space the filter out a bit and may or may not require a longer threaded insert depending on thicknesses involved. This style adapter would also avoid any overhang obstruction of those oil passages although it's likely not that significant. Here is a sketched cross-section of what I have in mind:

 

[ptsg]

Nice work!
On the oil filter adapter insert it appears from the pic that you machined a smaller diameter thin ring that press fit on the OD to the ID of the cast ring boss. There is an overhang of the insert over the cast oil passages. I'm trying to understand how that is going to seal correctly and not have a seeping leak, especially when there's a possibility of that thin ring flexing from over tightening the filter with that overhang? Did you use a boring head or rotary table to cut a flat base on the casting to create a flat surface for that insert to seat up against?

Here is an idea using an o-ring to make an adapter that avoids that potential issue. It would space the filter out a bit and may or may not require a longer threaded insert depending on thicknesses involved. This style adapter would also avoid any overhang obstruction of those oil passages although it's likely not that significant. Here is a sketched cross-section of what I have in mind:

Thank for the ideas and the sketch. All valid concerns indeed.

I only had about 3 to 3.5 mm (about 1/8") of thickness to work with. The o-ring idea is great, but didn't have much room to work with. I could also have cut the o-ring groove on the filter housing instead of on the ring.

I machined a mandrel with the M16x1.5 thread and did it so it would stick about 2" from the chuck and threaded the filter housing on it. This allowed be to use a boring bar to machine the inner diameter of the factory sealing ring to true up all the surfaces.

Then I machined the new ring, to press fit on the filter housing. On this ring, I machined a tiny groove on the outside diameter, just with the tip of the toolbit, then used Loctite 603 and pressed it into place. This idea was that it would provide a groove for the glue to sit and hopefully provide a good seal all around it.

Finally, I put the mandrel back on the lathe, and machined both surfaces flat. Also, on the ring, I machined a taper inside so it would give more clearance on that hole in the filter housing. Not entirely necessary but just an extra step to make sure. The angle of the photo above doesn't help and makes it look like it covers a lot of the hole but it really doesn't.

I think it will work fine but won't be surprised if it tries to leak on me.

One issue I didn't realize before is that the OD of the new filter bottoms out on the original sealing surface. While the seal of the filter sits proud about 2 to 3 mm, I'm a little concerned it may try to leak there. I may sill go ahead and turn the outside diameter of the original sealing surface down a little bit.

I hope I explained this in an understandable way.

 

[MTGreen]

Thank for the ideas and the sketch. All valid concerns indeed.

I only had about 3 to 3.5 mm (about 1/8") of thickness to work with. The o-ring idea is great, but didn't have much room to work with. I could also have cut the o-ring groove on the filter housing instead of on the ring.

I machined a mandrel with the M16x1.5 thread and did it so it would stick about 2" from the chuck and threaded the filter housing on it. This allowed be to use a boring bar to machine the inner diameter of the factory sealing ring to true up all the surfaces.

Then I machined the new ring, to press fit on the filter housing. On this ring, I machined a tiny groove on the outside diameter, just with the tip of the toolbit, then used Loctite 603 and pressed it into place. This idea was that it would provide a groove for the glue to sit and hopefully provide a good seal all around it.

Finally, I put the mandrel back on the lathe, and machined both surfaces flat. Also, on the ring, I machined a taper inside so it would give more clearance on that hole in the filter housing. Not entirely necessary but just an extra step to make sure. The angle of the photo above doesn't help and makes it look like it covers a lot of the hole but it really doesn't.

I think it will work fine but won't be surprised if it tries to leak on me.

One issue I didn't realize before is that the OD of the new filter bottoms out on the original sealing surface. While the seal of the filter sits proud about 2 to 3 mm, I'm a little concerned it may try to leak there. I may sill go ahead and turn the outside diameter of the original sealing surface down a little bit.

I hope I explained this in an understandable way.

Yes I think I follow. I like the groove idea to provide space for the locktite. What I wasn't clear on is if you machined a surface in the oil passage portion of the casting parallel to the filter seat for the insert to seat up against and provide for axial loading or if the insert is only being held suspended by the press fit OD?

Hopefully it will hold with the additional filter edge clearance cut as you mentioned. It occurred to me that if it does leak sometime down the line that groove for locktite could be replaced with a thin oring around the OD of the insert to allow for some flex.

Nice work and thanks much for sharing!

 

[ptsg]

Yes I think I follow. I like the groove idea to provide space for the locktite. What I wasn't clear on is if you machined a surface in the oil passage portion of the casting parallel to the filter seat for the insert to seat up against and provide for axial loading or if the insert is only being held suspended by the press fit OD?

Hopefully it will hold with the additional filter edge clearance cut as you mentioned. It occurred to me that if it does leak sometime down the line that groove for locktite could be replaced with a thin oring around the OD of the insert to allow for some flex.

Nice work and thanks much for sharing!

I did machine the surface as you said, so the ring bottoms out on a machined surface on the filter housing.

 

[ptsg]

In the last couple of days, I've pulled the rear gearbox out and started going through it. Found 3 bad bearings and seals and found out that it has surprisingly big gears for the PTO. Wasn't expecting that.

Both brakes had one broken shoe that got repaired on each side for some reason. Not sure what would've caused that. At least they were relined at some point, so I just need to clean those out and put it back together.

The shift rails had lots of rust as I said previously but also the plunger was so wore out that it didn't even have a point anymore to sit on the holes of the rails. Also, both springs were rusted and broken. Couple more things to fix.

Spacer/4WD selector. Has one bad bearing and looks like two bad seals.

Rear left side brake, axle and final drive:

PTO pictures. On this one, a needle bearing gave out and damaged the shaft (2nd) picture. Since the needles ran on the hardened shaft and while I can build the shaft back up, I can't recreate the hardness of it so I may replace this bearing with a bronze bushing instead. Still debating on that.

One thing I'm liking in this tractor so far is that it pretty much uses just off the shelf parts, like bearings, seals, pins, etc. Nothing proprietary to the manufacturer.

 

[etpm]

In the last couple of days, I've pulled the rear gearbox out and started going through it. Found 3 bad bearings and seals and found out that it has surprisingly big gears for the PTO. Wasn't expecting that.

Both brakes had one broken shoe that got repaired on each side for some reason. Not sure what would've caused that. At least they were relined at some point, so I just need to clean those out and put it back together.

The shift rails had lots of rust as I said previously but also the plunger was so wore out that it didn't even have a point anymore to sit on the holes of the rails. Also, both springs were rusted and broken. Couple more things to fix.

View attachment 840896 View attachment 840897

Spacer/4WD selector. Has one bad bearing and looks like two bad seals.

View attachment 840898 View attachment 840899

Rear left side brake, axle and final drive:

View attachment 840900 View attachment 840901

View attachment 840902 View attachment 840903

PTO pictures. On this one, a needle bearing gave out and damaged the shaft (2nd) picture. Since the needles ran on the hardened shaft and while I can build the shaft back up, I can't recreate the hardness of it so I may replace this bearing with a bronze bushing instead. Still debating on that.

View attachment 840904 View attachment 840905

One thing I'm liking in this tractor so far is that it pretty much uses just off the shelf parts, like bearings, seals, pins, etc. Nothing proprietary to the manufacturer.

There are welding rods that can be used to build up that shaft that will be plenty hard enough. But then you would need to grind it to size, also, the size would need to be very exact. One option could be to use a hardened bushing that is a press fit or a shrink fit onto the shaft. Once again the size needs to be controlled exactly. The shaft could be turned to a .00254 interference fit with a couple grooves about 1mm long and .07mm deep. The grooves would be for some Loctite. I think 609 is the right number. If you decide to use a bronze bushing I would suggest aluminum nickel bronze alloy. This alloy excels in high load situations. It will tolerate low lube situations better than many other bearing bronze alloys. It is quite slick. However, if oil starved for relatively long periods it will tend to wear less than the steel shaft running in the bushing.
Eric

 

[ptsg]

There are welding rods that can be used to build up that shaft that will be plenty hard enough. But then you would need to grind it to size, also, the size would need to be very exact. One option could be to use a hardened bushing that is a press fit or a shrink fit onto the shaft. Once again the size needs to be controlled exactly. The shaft could be turned to a .00254 interference fit with a couple grooves about 1mm long and .07mm deep. The grooves would be for some Loctite. I think 609 is the right number. If you decide to use a bronze bushing I would suggest aluminum nickel bronze alloy. This alloy excels in high load situations. It will tolerate low lube situations better than many other bearing bronze alloys. It is quite slick. However, if oil starved for relatively long periods it will tend to wear less than the steel shaft running in the bushing.
Eric

Thanks for all those suggestions. I'll see what I can find regarding the welding rods. I could rig a die grinder on the tool post and grind it to size if needed.

As far as oil starvation, that bushing will be under the oil level 100% of the time. That's why my first idea was the bushing. A couple grooves for the oil to flow in and should last a decent amount of time.

The shaft will only spin on the bush in the 540 PTO gear. If I use 750/540E, it's a direct drive on this area and the shaft spins at the same speed of the bushing.

 

[MTGreen]

Thanks for all those suggestions. I'll see what I can find regarding the welding rods. I could rig a die grinder on the tool post and grind it to size if needed.

As far as oil starvation, that bushing will be under the oil level 100% of the time. That's why my first idea was the bushing. A couple grooves for the oil to flow in and should last a decent amount of time.

The shaft will only spin on the bush in the 540 PTO gear. If I use 750/540E, it's a direct drive on this area and the shaft spins at the same speed of the bushing.

I've done that die grinder on the tool post trick several times with various rigid adapters and my experience has been that you don't get results like a real tool post grinder because you are limited by the die grinder bearings which tend to be on the loosey-goosey side in the runout department (probably deliberate to deal with grinding dust). I've found it works in some applications that you only need +/- 0.001-0.002" for it to work, but as etpm mentioned above you'll need a very exact fit here and unless you have an exceptional high precision bearing die grinder I'm thinking you're not going to have much luck. Of course YMMV

 

[ptsg]

I got sick right after Christmas, so progress was a bit slow. Still cleaned all of the rear gearbox parts. replaced one bad bearing, fix all the detent parts for the shift rails and fixed the damaged shaft for the PTO. Ended up just building the diameter back up and turn back to 16.00 mm on the dot. Will go with the bronze bushing route and see how long it lasts.

Got a little bit of an update on the head. He sent the head to a welder which said he didn't had enough space to fit the torch and fill the hole that the valve put on the exhaust port. But the engine shop guy says he can deal with the other damage no problem. I can deal with the hole, so that's fine and the head will be fixed. I also gave him a new set of valves and guides. Maybe this week I get it back, probably won't though.

Picture of the detent parts for the shift rails. I went ahead and pressed a ball from a bearing on the plunger, found two new springs and modified the set screw slightly. Also, using an air tool, I cleaned the detent dimples on the shift rails.

Pictures of the shaft I fixed and most of the gearbox put back together.

 

[2manyrocks]

Hope you get to feeling better. Good to watch your progress.

 

[ptsg]

Got the PTO gearbox all ready to go. Cleaning all the milk oil, wash all the parts and put it back together with a generous amount of grease on just about everything inside.

I don't know when this thing will be put back together in running condition, so I'm trying to prevent any rust from forming till then. I'm using a mixture of kerosene with paint thinner to wash all the parts and this leaves no protection against rust.

This is where that needle bearing failed. I was going over my bronze stock to machine a new bushing and lo and behold, I found just the bushing I needed. A sintered bushing 16 x 20 x 25 mm. Exact ID and OD I need, just 5 mm too long. No big deal, chuck it in the lathe and machine it down. Sure it's nice having something going my way for once.

I can now attach the PTO gearbox back to the rear main gearbox. It's only missing the seals, which I have already ordered all the seals for the entire tractor. Pretty much any oil seal on this tractor can go in with everything assembled, so I can leave those for last.

On this PTO gear box, direct drive is 750 PTO RPM or 540E. Going through the gears is 540 RPM. Technically, using 750, means that the bushing will have no wear at all since both shafts spin are coupled together. This is for the bottom PTO shaft, which is the standard 1 3/8" 6 spline shaft.

The top PTO shaft is 1 1/8" 6 spline shaft and spins all the time the engine is running, with no way to disengage it. It outputs 640 RPM at 3000 engine RPM in Low Range and 1000 RPM in High range.

 

[MTGreen]

You really bought a basketcase but by golly you're making it come together. Kudos to your tenacity and skill set. Looking great and thanks again for sharing

 

[ptsg]

You really bought a basketcase but by golly you're making it come together. Kudos to your tenacity and skill set. Looking great and thanks again for sharing

This one is turning out to be quite a basketcase. Not sure if I won on this one. Just about everything I take apart, there is something wrong with it and I still have the front half and steering box to pull apart.

I guess I got lucky on my crawler tractors and generator I bought for dirt cheap. Those required minimal fixes, just a nice clean up and paint job for the most part.

Anyway, I still have less than €800 on it and it's still worth more than that in parts. I'm stubborn and I refuse to throw the towel, yet...