I recently got a ford 335 industrial tractor and the differential lock is not working - the foot pedal lays on the footrest and there is no spring return to an up position. The lock is not engaged because I've seen one wheel moving in mud but not the other, the linkage is not frozen and moves freely, and the lever travels up and down and I can feel it touch metal inside the housing when moving it manually after the linkage is removed. I thought I would follow the instructions in the manual for overhaul and adjust the linkage to see if that would help - but I don't know what normal would feel like in moving the lever up and down to tell if/when it might be engaged (necessary for adjusting the linkage) or even if the internal forks are intact - and also don't know how to test the spring in the connecting rod to see if it might be frozen. Any advice or suggestions would be appreciated.
help needed to adjust differential lock on a ford 335 industrial tractor
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ovrszd
Epic Contributor
- Joined
- May 27, 2006
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- Missouri
- Tractor
- Kubota M9540, Ford 3910FWD, Ford 555A, JD2210
Hmmmmm. The spring feel is created on the outside, if this tractor is like the AG models. My 3910 peddle is not connected directly to the shaft going into the rear axle. It pulls a spring, which is attached to the shaft. So with what information you have given I don't have much to offer. Gonna require you to lay under the machine and study the linkage setup so you know what's going on under there when you push the pedal. There is adjustment to ensure the pedal actually activates the spring system. You need to look for that adjustment and work on getting the pedal to actually create some sort of reaction to the diff lock shaft. Pics would be awesome.
I believe completely in the K.I.S.S. principle. Keep It Simple Stupid. Look for an easy fix before getting convinced that it's the "Oh My God, I Gotta Tear My Tractor Apart" fix.
I believe completely in the K.I.S.S. principle. Keep It Simple Stupid. Look for an easy fix before getting convinced that it's the "Oh My God, I Gotta Tear My Tractor Apart" fix.
Ultradog MN
Gold Member
I've had two of them that way. One I sold that way and the other one I need to fix one of these days.
I think it is the big coil spring inside that has failed. Part # 36 at the link below.
I know you will need to pull one of the axle housings (trumpets) off. And I know it can be done if you pull the LEFT side and then pull the differential. You might be able to do it from the right side but I am not positive. I will pull the left side when I do it unless someone can verify it can be done from the right.
I have been into those rear ends several times and they are really easy, ie, not complicated at all. Just a bit of grunt work.
The one I have to fix is on a 4000 with double reduction rear end so it is a bit heavier than your 335.
PS,
Technically, your 335 is a Utility model - not an Industrial model.
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
I think it is the big coil spring inside that has failed. Part # 36 at the link below.
I know you will need to pull one of the axle housings (trumpets) off. And I know it can be done if you pull the LEFT side and then pull the differential. You might be able to do it from the right side but I am not positive. I will pull the left side when I do it unless someone can verify it can be done from the right.
I have been into those rear ends several times and they are really easy, ie, not complicated at all. Just a bit of grunt work.
The one I have to fix is on a 4000 with double reduction rear end so it is a bit heavier than your 335.
PS,
Technically, your 335 is a Utility model - not an Industrial model.
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
thanks for the comments and parts link - much appreciated. I have the shop manual and it appears I could access everything by pulling the right side without having to remove the differential....so will do that if no success in adjusting the linkage first. will take some pictures and post them to clarify my questions and the linkage setup.
Ultradog MN
Gold Member
I was looking at a different parts diagram and now I'm wondering if I was incorrect in my post above.
See link below.
Now I am thinking it could be the set screw/lock nut #25/26 have loosened in the shift fork #24.
In which case you would want to remove the right trumpet.
I think that would make more sense then the coil spring having failed.
I probably wont get at mine till late spring some time. When were you thinking of attacking yours?
I will appreciate any updates if you do yours before that.
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
See link below.
Now I am thinking it could be the set screw/lock nut #25/26 have loosened in the shift fork #24.
In which case you would want to remove the right trumpet.
I think that would make more sense then the coil spring having failed.
I probably wont get at mine till late spring some time. When were you thinking of attacking yours?
I will appreciate any updates if you do yours before that.
Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors.
yes, the set screw seems like a possibility. It's been too cold to work on it but should warm in the next couple of days so will do more - but will focus on the pedal linkage adjustment first before re-setting the set screw because of being unsure what the set screw adjustment should "feel" like - in the manual it says to lower the lever until you can feel contact being made internally via the fork, but when I play with that I'm not positive when contact is made and if set wrong could possibly do damage. For reference, when I move the lever without linkage attached the travel is about 1 inch (at the end of the lever) from full up to full down, which appears to be close to what the pedal will travel. And the lever will return by itself to the full up position but not with much lifting power (not sure if it would raise the pedal if linkage is connected).
I assume the spring in the connecting rod helps return the pedal to the up position when the differential unlocks, but not sure how much travel the spring should have or be set at when adjusting the linkage (my basic question). I wanted to be sure the spring in the connecting rod was not frozen so yesterday removed the rod and used a ratchet to extend the rod (compresses the internal spring) and the travel is about 1/2"....not sure if more is to be expected - does anyone know how much travel it's designed to have?
I assume the spring in the connecting rod helps return the pedal to the up position when the differential unlocks, but not sure how much travel the spring should have or be set at when adjusting the linkage (my basic question). I wanted to be sure the spring in the connecting rod was not frozen so yesterday removed the rod and used a ratchet to extend the rod (compresses the internal spring) and the travel is about 1/2"....not sure if more is to be expected - does anyone know how much travel it's designed to have?
ovrszd
Epic Contributor
- Joined
- May 27, 2006
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- 33,499
- Location
- Missouri
- Tractor
- Kubota M9540, Ford 3910FWD, Ford 555A, JD2210
The spring in the connecting rod is designed to allow you to push the pedal to the floor, even though the internal gears might not be properly meshed. This holds the sliding gear against the opposing gear until the teeth mesh and the locker engages.
The internal spring is designed to put constant pressure against that gear in the opposite direction. So the locker will disengage when pressure equalizes and the locker is no longer needed.
The intent is for the operator to apply pressure to the foot pedal until the locker engages, then release the pedal. Locker will disengage when not needed.
The internal spring is designed to put constant pressure against that gear in the opposite direction. So the locker will disengage when pressure equalizes and the locker is no longer needed.
The intent is for the operator to apply pressure to the foot pedal until the locker engages, then release the pedal. Locker will disengage when not needed.
makes sense....here are the instructions on adjusting the linkage for the differential lock taken from the workshop manual, with questions I have in parenthesis (???) that I would appreciate comments on: question:
1. remove the cotter pin and clevis pin and disconnect the differential lock operating pedal.
2. depress the operating lever until the differential lock is fully engaged. (how do you know if it's fully engaged? how much travel should be expected, measured from the end of the operating lever?).
3. Loosen the locknut, then adjust the length of the operating rod and clevis assembly until the clevis pin can be inserted without compressing the spring in the operating rod. (what position should the pedal be in when making the measurement and connection - resting on the footrest, raised fully, or something else?)
4. remove the clevis pin, then shorten the operating assembly by one turn. Re-insert the clevis pin retaining with a new cotter pin.
5. Tighten the locknut to the correct torque.
6. Check that when the load is removed from the pedal and the rear wheels are free to rotate, the differential lock linkage disengages automatically and the pedal assembly returns to the raised position. The wheels should then rotate independently. (how can this be tested in the shop - have both wheels raised off the ground? also, what is it that has enough lift to raise the pedal after it disengages?).
any comments would be appreciated.
1. remove the cotter pin and clevis pin and disconnect the differential lock operating pedal.
2. depress the operating lever until the differential lock is fully engaged. (how do you know if it's fully engaged? how much travel should be expected, measured from the end of the operating lever?).
3. Loosen the locknut, then adjust the length of the operating rod and clevis assembly until the clevis pin can be inserted without compressing the spring in the operating rod. (what position should the pedal be in when making the measurement and connection - resting on the footrest, raised fully, or something else?)
4. remove the clevis pin, then shorten the operating assembly by one turn. Re-insert the clevis pin retaining with a new cotter pin.
5. Tighten the locknut to the correct torque.
6. Check that when the load is removed from the pedal and the rear wheels are free to rotate, the differential lock linkage disengages automatically and the pedal assembly returns to the raised position. The wheels should then rotate independently. (how can this be tested in the shop - have both wheels raised off the ground? also, what is it that has enough lift to raise the pedal after it disengages?).
any comments would be appreciated.
Ultradog MN
Gold Member
Ovrszd gives a good description of how the linkage works.
The external linkage is pretty much set at the factory and never needs to be readjusted. At least I've never heard of one needing adjustment. But satisfy your own curiosity of course.
The external linkage is pretty much set at the factory and never needs to be readjusted. At least I've never heard of one needing adjustment. But satisfy your own curiosity of course.