Ford 420 Shuttle Shifting Help

[RedBarnFarm]

Hoping someone can guide me to another possible answer on a long-term reoccurring problem with my shuttle shift. So the history is the tractor developed an issue where it was slow to engage in reverse or would only engage at high rpm after 10 or 20 seconds, forward was fine. Had a mechanic work on it and they split it and went through and replaced seals. Got the tractor back and had the same issue after about an hour of running it then the shuttle shift would no longer move. So here is what I have done since then -

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.

With some forum help I was directed how to remove the blocker valve and change the pins, seal, and springs. I did this and bam, everything worked great for a couple of months. Granted I wasn't using the tractor extremely long periods of time or in extremely hot weather.

Now that we have hit hay season I started loading and move bales with it and it has gone back to only engaging in reverse at high rpms after a delay, on top of that now it does the same thing in forward which is a new symptom. It was mentioned in my last post about the blocker valve if it didn't solve the problem it might need to be split and look at the oil diverter - is this now the likely culprit or since it did go back to working for several months could it be something else? It is 100 degrees here and I am running mostly early morning late evening but it is still probably in the 90s. Any thoughts?

 

[RedBarnFarm]

Would it be possible the oil itself I have in there is an issue? Going to check the bucket for the correct numbers but just a thought.
Checked - says it meets 134D.

This post was edited by RedBarnFarm on 06/13/2022 at 02:43 pm.

 

[Check Break]

(quoted from post at 08:29:12 06/13/22) Hoping someone can guide me to another possible answer on a long-term reoccurring problem with my shuttle shift. So the history is the tractor developed an issue where it was slow to engage in reverse or would only engage at high rpm after 10 or 20 seconds, forward was fine. Had a mechanic work on it and they split it and went through and replaced seals. Got the tractor back and had the same issue after about an hour of running it then the shuttle shift would no longer move. So here is what I have done since then -

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.

With some forum help I was directed how to remove the blocker valve and change the pins, seal, and springs. I did this and bam, everything worked great for a couple of months. Granted I wasn't using the tractor extremely long periods of time or in extremely hot weather.

Now that we have hit hay season I started loading and move bales with it and it has gone back to only engaging in reverse at high rpms after a delay, on top of that now it does the same thing in forward which is a new symptom. It was mentioned in my last post about the blocker valve if it didn't solve the problem it might need to be split and look at the oil diverter - is this now the likely culprit or since it did go back to working for several months could it be something else? It is 100 degrees here and I am running mostly early morning late evening but it is still probably in the 90s. Any thoughts?

Do you have a manual? It will show you how to check shuttle pressure. Check when it's 100 degrees and you're running hard. Need to determine if your front pump is good. Then I'd clean the blocker valve body out again in case there's debris in the oil that's causing the valves to stick. I assume you changed the transmission filter when you split her the first time and that your mechanic looked at the pickup screen and it wasn't plugged.

Sounds like it works ok after it goes into gear. If so, then you have a valve problem, or oil to valve problem. That leads back to the oil diverter and another split. Could be a broken sealing ring or o-ring or bad front pump, or worn diverter bore. Start with the simple stuff first. Change your transmission filter. Cut the old one open and check for debris in the pleats. If there's debris, change the oil and clean the blocker valve body again. Maybe this will get you through hay season. At the end of hay season, cut the filter open again. If more debris, time to dive in and figure out what's coming apart, which for all intents and purposes means a shuttle rebuild. If there's no debris in the filter, then cleaning the blocker valve body again is probably a waste, but easier than a split. That's an earfull for now. Post back when you have pressure readings or more and maybe we'll have a better idea of what's going on.

 

[RedBarnFarm]

I do have the manual for it - I will obtain a pressure gauge and attempt to run a test on it. I assumed, and assumed incorrectly when the mechanic did the split he replaced the filter with the fluid. However I took off the front grill and shielding tonight and the entire area was covered in debris, dirt and oil. I pressure washed it all off and the filter on it is the last filter I put on it as I wrote the date and engine hours on it when I changed it. So it has not had a filter change.

I went and got a new filter and bought some UTF that meets or exceeds 134D to put in it. However before I do that I did find a leak in the housing the filter up front attaches to. It would be where the two metal lines go in where I have put an arrow. Not sure how these attach or why it is leaking here but it is enough that it was obvious after 2 or 3 minutes of running. Would this have an impact as well? Would you be able to tell me how those 2 lines attach in that body?

 

[Sean in PA]

#11 in the parts list is an o-ring, so they are likely O-Ring Boss (ORB) connectors. If that is what they are, then the hex ends should swivel on the ends of the lines and unscrew from the filter housing with an o-ring behind each one. Replace the o-rings and tighten them back up and it should be good. Part number for the o-rings is 9672467 and the description is 0.103'' Thk x 0.549'' ID, -113, Cl 5, 75 Duro.

 

[RedBarnFarm]

I took a look and I didn't see a head on the end of these lines, they appear to just go into the housing. There is a bracket above them held with a screw. I am assuming maybe take the bracket off and these just lift out? I may have unbolt the filter bracket from the frame by the looks of it to get enough slack to take them out if I am looking at it correctly. I went ahead and ordered o-rings.

 

[Check Break]

(quoted from post at 21:20:20 06/14/22) #11 in the parts list is an o-ring, so they are likely O-Ring Boss (ORB) connectors. If that is what they are, then the hex ends should swivel on the ends of the lines and unscrew from the filter housing with an o-ring behind each one. Replace the o-rings and tighten them back up and it should be good. Part number for the o-rings is 9672467 and the description is 0.103'' Thk x 0.549'' ID, -113, Cl 5, 75 Duro.

You're going to laugh. They're just bare lines with an o-ring on them. They slip into the filter head and are retained by the plate and screw. This allows them to move a bit without cracking is my guess. Always seemed low budget to me but there's thousands of them out there to prove me wrong.

 

[RedBarnFarm]

Good to know, I will take them out and replace the o-rings and put them back in then. Afterwards change the filter and oil and see where we stand. Will grab a pressure gauge as soon as I can climb off the baler in the daylight for a bit.

 

[Check Break]

So, back to Plan A. Pressure check. Filter check. Maybe clean the blocker valve body again, depending upon your pressure reading. You didn't correct my assumption that she acts normal after going into gear so maybe your pressure is good, as it takes pressure to compress the clutch pack. Still feels like a valve problem or oil to the valve problem caused by hot (and now thinner) oil.

 

[Check Break]

(quoted from post at 14:50:45 06/15/22) Good to know, I will take them out and replace the o-rings and put them back in then. Afterwards change the filter and oil and see where we stand. Will grab a pressure gauge as soon as I can climb off the baler in the daylight for a bit.

That gauge should attach to a test port (line) in front of the oil divider accessed through the inspection plate under the bellhousing. Buy a long hose so you can use the gauge while driving the tractor. More fun after a hard days work.

 

[RedBarnFarm]

Yes sorry I missed that - you are correct it acts completely fine AFTER it engages. I was even pulling a trailer with 8 round bales on it without any issue at all down the road after it started happening.

 

[Check Break]

(quoted from post at 15:47:24 06/15/22) Yes sorry I missed that - you are correct it acts completely fine AFTER it engages. I was even pulling a trailer with 8 round bales on it without any issue at all down the road after it started happening.

Doesn't sound like a pressure problem. Your clutch pack is locked up tight to be able to do that. You said you didn't see a problem with the linkage. Disconnect the linkage at top of bellhousing where it terminates at the bellcrank on the vertical shaft outside the bellhousing. How much play do you have when you move the bellcrank one way, then the other. If no play, then the pin that connects the bellcrank on the vertical shaft (inside the bellhousing) to the main valve should be good. If there's play, the pin may be worn. It's a PIA to remove, but if that pin is worn, it could be the cause of your entire problem.

 

[RedBarnFarm]

I unpinned the linkage at this point that I circled. With the engine off I attempted to cycle through the 3 positions. In between each position engaging there was for sure what I guess would be slack before it engaged to the next spot. You can definitely wiggle it back and forth quite a bit before it feels like it engages or disengages.

 

[Check Break]

Don't have much time for a response. The part you circled, 20, is the inside bellcrank. 23 is the pin between the inside bellcrank and the main valve stem. I'm pretty sure you were actuating the outside bellcrank, just posted the wrong picture. All of your symptoms can be caused by a worn pin, part no. 23. It takes a Houdini to change it, but it can be changed from underneath the bellhousing through the inspection plate. This is made easier if you remove the steering gear and go through the top, like you did to get at the blocker valve body. It would be worth a look at the pin before you split her again, given the amount of slop you describe when actuating the top bellcrank.

 

[RedBarnFarm]

Thank you for your response. I will go ahead and order a new pin as well. Hopefully my son may can change it from underneath, lot smaller hands and arms. Will give it a go. O-rings came in today so I will be replacing those and the filter/oil as well.

 

[Check Break]

(quoted from post at 09:36:15 06/17/22) Thank you for your response. I will go ahead and order a new pin as well. Hopefully my son may can change it from underneath, lot smaller hands and arms. Will give it a go. O-rings came in today so I will be replacing those and the filter/oil as well.

The pin takes a cotter pin to keep it in place. Can be sourced locally if you've already ordered.

 

[RedBarnFarm]

(reply to post at 16:34:59 06/17/22)

Ok so I may have found the problem - but now I am super confused... So I drained all the oil out of the case so I could change the filter and put better oil back in and you will never guess what I found stuck to the magnet on the drain plug... A blocker valve pin. How in the world did that get there and how was the tractor working all this time? I guess it is possible when I replaced them I didn't get it in the hole with the magnet but I didn't have any doubts at the time that I did..

This post was edited by RedBarnFarm on 06/17/2022 at 07:53 pm.

 

[Check Break]

Ok so I may have found the problem - but now I am super confused... So I drained all the oil out of the case so I could change the filter and put better oil back in and you will never guess what I found stuck to the magnet on the drain plug... A blocker valve pin. How in the world did that get there and how was the tractor working all this time? I guess it is possible when I replaced them I didn't get it in the hole with the magnet but I didn't have any doubts at the time that I did..

This post was edited by RedBarnFarm on 06/17/2022 at 07:53 pm.
[/quote]

That bv pin may have been in there from before you owned it or may be something lost and replaced by the mechanic who split her for you. It's not something that can pass through the oil diverter after installation and end up in the bottom of the case. It had to fall into the transmission case after the oil diverter was removed. If you check your blocker valve again, my guess is it is exactly the same as when you installed it.

 

[Check Break]

If you are going into the bellhousing again to RR the control valve pin, you could take a look at the pressure regulator and bypass valve. There's not much to them. I've never had the need to do this while the oil diverter is installed and wouldn't recommend doing so until after a pressure test and determination that you have low pressure. There could be a speck of $hit causing the pressure regulator to hang up, but I have a hard time convincing myself of this. Would more likely be a broken spring.

When you had no F or R, the blocker valve was a logical place to look, as it prevents oil from traveling to the main control valve. The blocker valve is designed to prevent oil from traveling to the control valve at high rpm, so you don't damage your clutch packs. In your situation, you can't shift into F or R unless you rev her up, which should trigger the blocker valves and prevent a change in direction. So, the question is why won't she go into F or R at low rpm. It's back to the pressure test, which I have a feeling is going to show good pressure. That leaves the control valve pin. If it's worn, it's not cycling the control valve completely and the control valve isn't being moved by the linkage. It's completing its travel when (my guess) vibration from the high rpm causes it to complete its travel, probably assisted by properly functioning blocker valves that cut off oil to the control valve and reduce any hydraulic pressure against it.

I guess this is a long winded way of saying, check your pressure and if good, check the control valve pin. If both are good, then check the pressure regulator and bypass valve for a broken spring or debris. I can't think of anything else to do, other than check all of your linkage to make sure there's no slop, before you split her again and take her down to component parts to look for internal wear. You'll replace all orings, sealing rings and gaskets again if there's nothing that needs to be replaced, hoping one of those is leaking and a new one will fix the problem.

 

[RedBarnFarm]

Oil changed to a higher grade, filter changed, Took the blocker valve off - looked ok although I couldn't pull one of the pins out with the magnet. Changed those o-rings on the lines going in to the filter. No change. Time to pressure test like you said - just need to see what sizes I need to build me a test line. Ordered that pin but won't be in until late next week.

 

[Check Break]

(quoted from post at 14:42:57 06/18/22) Oil changed to a higher grade, filter changed, Took the blocker valve off - looked ok although I couldn't pull one of the pins out with the magnet. Changed those o-rings on the lines going in to the filter. No change. Time to pressure test like you said - just need to see what sizes I need to build me a test line. Ordered that pin but won't be in until late next week.

The pin is 1/4" diameter x 5/8" long. The cotter pin that retains it is 1/16" diameter x 1/2" long.

 

[RedBarnFarm]

Awesome thank you, can probably locate something local then. Is this the plug for the test port? If so should I be prepared for oil to come streaming out when I take the plug out?

 

[Check Break]

That's not the test port. Normally, there is an elbow in the distributor housing facing the torque converter, just below the blocker valve. There should be a steel line from the elbow to the bottom of the oil distributor secured to the face of the distributor. Sounds like you don't have one. Those two caps to the right of the plug you are asking about are the bypass valve and pressure regulator. Regulator is towards the outside of the distributor and bypass is closest to the center of the distributor. Bypass consists of the cap you see, an oring, spring and check ball. Regulator consists of the cap you see, an oring, spring and valve.

 

[Check Break]

I thought I had the trade size (Dash Number) for the orings but my old cheat sheet only covers the S94-s. The S95-s are hard, so if you match them up, use 90 duro-s.

Correction: Ford part number is 167269. Messick's parts online shows it to be a -910. 0.097"' Thk x 0.755'' ID, and 90 Duro. Their parts diagram also shows the steel line from the elbow below the blocker valve that runs on the outside face of the oil distributor to just below the bottom of the distributor. Shows a pipe plug in the end of the line, 1/8" x 27.

Does your 420 have the steel line or did someone remove it?

This post was edited by Check Break on 06/19/2022 at 08:56 am.

 

[RedBarnFarm]

No steel line at all in there. I guess someone removed it at some point. The linkage pin is also proving to be an issue - I lifted the steering box and fuel tank where I can access from the topside and there is no room to take the pin out. For whatever reason no matter what position I have the shifter in, neutral, forward or reverse the rod never travels far enough beyond the bell housing to lift the pin out. I've tried it with the tractor running so I can make sure it is traveling beyond the pins as well. It hits the bell housing before you get enough to remove it so I am not sure what to do there. It isn't by much but it is enough to keep it from coming out for sure.

The bypass valve and pressure regulator, did you say those can be done from the bottom access port? They are off to the side of the port so not able to get a straight shot with a socket, maybe with a knuckle of some sort but wanted to make sure that was the way to remove those before I tried it. Thanks again for all the help. I wish there was a mechanic in the area that could tackle it and do a good job, I'd take it to them at this point if I could.

 

[RedBarnFarm]

Best picture I could get, but I think you can see it - it won't clear the housing above it. It needs to come a bit further in but that's as far as it wants to go.

 

[Check Break]

Do you see any wear on the pin. Any chance it's longer than 5/8". Could be that it was replaced with a 3/4" pin by a previous owner.

 

[RedBarnFarm]

(quoted from post at 19:42:21 06/20/22) Do you see any wear on the pin. Any chance it's longer than 5/8". Could be that it was replaced with a 3/4" pin by a previous owner.

Hard to tell but if I actuate the lever from outside the bell housing and watch it there is some slop, I can visibly see a gap between the hole the pin goes through and the pin itself as I move the lever back and forth. If I had another 1/8th of an inch it would likely lift out like it is suppose to. In the picture if it traveled just a bit further to the inside it would clear that lower part of the housing and lift out. Where it is stopping I don't believe it would make a difference if the pin was 5/8ths as it still wouldn't have room to lift out unless the valve went back towards the center another 1/8th of an inch. Is there any reason that wouldn't move more towards the center? How would you go about replacing that pin unless it will slide further?

It is striking the housing where I circled. Slightly more towards the inside and I think it would be fine.

This post was edited by RedBarnFarm on 06/20/2022 at 08:09 pm.

 

[Check Break]

This is opening a can of worms if you can't get her back together but if you go to Messick's parts lookup and look at the parts diagram for the oil distributor, you will see you can back off the plug and/or the sleeve which will allow the control valve to travel further into the distributor. You should replace the orings if you do this. I'd back the sleeve off just enough to for the pin to clear the case and hope she reseals first. Clean the surface of the control valve before it travels further into the distributor. I'm worried you won't be able to put the control valve back together and will end up splitting her so tread lightly. Maybe the the bellcrank or valve is also worn.