Bizzare differential lock problem...

[linrick1]

Hey all, what could possibly cause the diff. lock on our Ford 1900 to engage not when I depress the foot pedal but when I reach down and pull UP on it?! There is no linkage at all, just pivots on the shaft that goes into the housing so I have no clue as to why it would be doing this....I cant imagine it is good for anything to be yanking up on it so Im leaving it alone until I can figure out what is wrong. They dont mention much about the diff. lock in the service manual (unless Im missin it)...any ideas? Thanks, Rick

 

[jimmer2880]

Has it always done this, or just start?

Sounds to me like the petal slipped on the pin

 

[RickB]

Hey all, what could possibly cause the diff. lock on our Ford 1900 to engage not when I depress the foot pedal but when I reach down and pull UP on it?! There is no linkage at all, just pivots on the shaft that goes into the housing so I have no clue as to why it would be doing this....I cant imagine it is good for anything to be yanking up on it so Im leaving it alone until I can figure out what is wrong. They dont mention much about the diff. lock in the service manual (unless Im missin it)...any ideas? Thanks, Rick

There's nothing wrong, they just do that. The engaging collar is moved by a cam connected to the pedal. The cam doesn't care whether it is rotated up or down.

 

[Hooked_on_HP]

Rick, Is what you are saying is when the diff pedal is in the up position both rear tires are locked together and when you push it down it allows 1 tire to spin. I looked in the service manual and your right, it doesn't say much about it. Hopefully Rick B or one of the other tec's will see this and give you some ideas. If not try posting it on the NH forum.
Bill

 

[linrick1]

Thanks for the replies guys, I guess I didnt explain the problem too well. With the diff. lock disengaged the pedal is in the correct position, about three or so inched above the footboard at my right heel. When I step on the pedal and push it down to lock the diff. it moves smoothly through its full range of travel but the lock does not engage. Release the pedal and it returns to its neutral position-again the diff is not locked. Now if I reach down and pull it up from the neutral position it seems as though it wants to lock.... exactly opposite of how it should work...dont know if that clears it up at all, hope to figure it out soon, thanks, Rick

 

[Hooked_on_HP]

Now that I understand the problem better RickB's answer makes since. If you go on the NH parts web site you will see how this works. Apparently you are getting some wear on the cam assembly or the pin has gotten twisted from forcing it and when you push down,the floor board is preventing the lever from engaging totally. On my 1900 when I put my heel on the diff. lock it doesn't engage until one tire has has spun a little to allow the pins to line up. Then the lever will go down to the floorboard. I never force it I just rest my heel on it . There is no adjustment. The service manual shows if you remove the tower for the TPH you can get to it. It doesn't look complicated.
Bill

 

[linrick1]

Thanks guys, I have never had the occasion to use the diff. lock (believe it or not) until just the other day and when I did go to use it there was nothing. I know the previous owner never had occasion to force it to lock and know I never have so Im wondering if it might just be hung up from lack of use....wishful thinking? Either way it sounds like Im going to have to open her up, we shall see.....Rick

 

[Eagleview]

It sounds to me that the link rod arm has gone over the knot and is working in reverse .