Ford 420 Shuttle Issue

[RedBarnFarm]

So I had some trouble a while back with my Ford 420 not wanting to engage in reverse or it was slow to engage in reverse. Had a mechanic work on it and they split it and went through and replaced seals. Got it back and it still did the same thing, not as bad but still had issues. With some help from this forum I took a crack at it and found a worn linkage pin that I replaced from underneath the tractor through the access panel. It has been working good for the last 5 months until today. I started it up and the shuttle lever didn't seem to want to go in forward or reverse - I took it out of gear and put it back and gear and tried the shuttle lever and it worked, backed out of the barn went and got some hay and when I came to the gate I put the shuttle in neutral. Got back on the tractor and the shuttle lever doesn't want to move. I mean it moves but it doesn't actuate in forward, reverse or neutral. It feels like it is stuck.

I checked the fluid and that was good, opened the access panel underneath and checked all the linkage and didn't see anything wrong there. Turned the tractor back on and looked in the panel and things are spinning. It will shift in all gears but won't shift the shuttle at all. Engine RPM at idle. Not particularly cold and have tried it with the engine warm and cold with no luck.

Any ideas where to go next?

 

[shaun wallace]

How fast is engine running ? If over 1100-1200 rpm blocker valve wont let shift. If 7-800 rpm blocker pins stuck. Have to pull fuel tank and steering box to access.

 

[RedBarnFarm]

(quoted from post at 20:38:27 01/30/22) How fast is engine running ? If over 1100-1200 rpm blocker valve wont let shift. If 7-800 rpm blocker pins stuck. Have to pull fuel tank and steering box to access.

7-800 rpm. If I disconnect the fuel line and steering arm and tach I can pull it all as one piece right? Just unbolt the steering box and lift it up with a hoist maybe?

 

[shaun wallace]

steering lines too. never tried but good idea, just mite work.

 

[Check Break]

(quoted from post at 08:31:01 01/31/22)

(quoted from post at 20:38:27 01/30/22) How fast is engine running ? If over 1100-1200 rpm blocker valve wont let shift. If 7-800 rpm blocker pins stuck. Have to pull fuel tank and steering box to access.

7-800 rpm. If I disconnect the fuel line and steering arm and tach I can pull it all as one piece right? Just unbolt the steering box and lift it up with a hoist maybe?

If you drain the tank, it will be easier on your back. Disconnect fuel lines (return and main), instrument cluster wiring, tach cable, drag link or pitman arm, transmission linkage, throttle linkage. I think that's it. She will balance on the bottom of the steering gear when you set her down or slide her over.

 

[RedBarnFarm]

Finally got around to getting this tractor in the shed and pulled apart. I pulled the 2 pins out of the body with a magnet. They have some scars around the top edges. Maybe this was enough to create the problem? I assume at this point I probably need to open the blocker valve up and make sure everything looks good in there and replace the seals while I have it out?

 

[RedBarnFarm]

(quoted from post at 20:38:27 01/30/22) How fast is engine running ? If over 1100-1200 rpm blocker valve wont let shift. If 7-800 rpm blocker pins stuck. Have to pull fuel tank and steering box to access.

I've taken the blocker valve apart and have not found any debris or anything like that. I am waiting on the seals to come in to put it back together and drop the new pins back in. Is there anything else I need to do? I can't really see down in the holes the pins were in as I have the steering assembly hoisted above it about 10 inches so enough space to get the valve in and out but not much room to look. Would there be debris in those holes for the pins to drop in I should worry about? I'm nervous I haven't came across anything I thought was an obvious issue - will put it all back together and find out I guess but in the meantime could there be something else I might need to check that would cause my problem?

 

[Check Break]

I've taken the blocker valve apart and have not found any debris or anything like that. I am waiting on the seals to come in to put it back together and drop the new pins back in. Is there anything else I need to do? I can't really see down in the holes the pins were in as I have the steering assembly hoisted above it about 10 inches so enough space to get the valve in and out but not much room to look. Would there be debris in those holes for the pins to drop in I should worry about?

Those old pins don't look so good. Are you also replacing the springs and gaskets. Does your shuttle shift easy with the blocker valve removed. Did you use the correct size pin to pin the bellcrank linkage to the main shuttle valve. Sounds like the pin is still in place like it should be. Is the bellcrank still pinned to the vertical shaft. Sometimes the roll pin breaks and the bellcrank moves, preventing it from actuating the main shuttle valve. This is not entirely obvious when you check it out. Have someone move the shuttle shift lever while you watch the bellcrank closely. If all the linkage is correct, from the newly installed pin at the main shuttle valve back to the shuttle selector, clean up and reinstall the blocker valve. If this doesn't solve your problem, then you're running out of easy solutions. Your machine doesn't have a dump valve so from here, you'll have to split it again and have a look at the oil diverter. Problem is, you may as well go all the way to the back of the shuttle if you have to go in, so as to insure she'll run another 10,000 hours after you close her up.

 

[RedBarnFarm]

(quoted from post at 23:04:05 02/21/22)

I've taken the blocker valve apart and have not found any debris or anything like that. I am waiting on the seals to come in to put it back together and drop the new pins back in. Is there anything else I need to do? I can't really see down in the holes the pins were in as I have the steering assembly hoisted above it about 10 inches so enough space to get the valve in and out but not much room to look. Would there be debris in those holes for the pins to drop in I should worry about?

Those old pins don't look so good. Are you also replacing the springs and gaskets. Does your shuttle shift easy with the blocker valve removed. Did you use the correct size pin to pin the bellcrank linkage to the main shuttle valve. Sounds like the pin is still in place like it should be. Is the bellcrank still pinned to the vertical shaft. Sometimes the roll pin breaks and the bellcrank moves, preventing it from actuating the main shuttle valve. This is not entirely obvious when you check it out. Have someone move the shuttle shift lever while you watch the bellcrank closely. If all the linkage is correct, from the newly installed pin at the main shuttle valve back to the shuttle selector, clean up and reinstall the blocker valve. If this doesn't solve your problem, then you're running out of easy solutions. Your machine doesn't have a dump valve so from here, you'll have to split it again and have a look at the oil diverter. Problem is, you may as well go all the way to the back of the shuttle if you have to go in, so as to insure she'll run another 10,000 hours after you close her up.

I did order new seals for the blocker valve, new pins, and 2 new springs as well. Just waiting on those to arrive. I don't have all of the shuttle shift linkage back up to the steering column hooked back up but I did try moving the shift linkage right where it comes out of the housing and everything seemed to move smooth. I could feel it actuate in to the forward, reverse and neutral positions. Hopefully that is a good sign. All the other linkage pins I have been able to find / see seems to be in good order.

 

[Check Break]

I did order new seals for the blocker valve, new pins, and 2 new springs as well. Just waiting on those to arrive. I don't have all of the shuttle shift linkage back up to the steering column hooked back up but I did try moving the shift linkage right where it comes out of the housing and everything seemed to move smooth. I could feel it actuate in to the forward, reverse and neutral positions. Hopefully that is a good sign. All the other linkage pins I have been able to find / see seems to be in good order.

Look carefully at the bellcrank inside the bellhousing. Is it twisted on the vertical shaft as in, has the roll pin started to fail. Does it move the same distance left of center (neutral) as it does right of center. Sounds like the main valve snaps in when you move it right and left. Blocker valves can be tempermental. If new ones don't solve your problem and you're satisfied with your linkage, you can take a pressure test before you split her again. Failure to move in both directions is usually something simple, but it isn't always so.