420c Throttle rod assembly.

[Davie Sprocket]

I have several manuals but none show the throttle rod assembly, the one i have says to refer to the 40 manual. I am trying to figure out how the spring and washers all fit together on the end with the throttle handle.

Thanks

Dave

[terra66]

I know this is an old post, but I have the exact same question-specifically if there are one or two washers on the engine side of the dash panel.

[JimAnderson]

For 420 80001 to 139999 from the dash 2 friction disks(cork) then
1 thrust washer ,1 spring then 1 retaining washer then a roll pin.
John deere parts manual PC-505.Hope this helps,JimAnderson

[terra66]

That's exactly what I needed - thanks!

[Lavoy]

One friction disk goes on either side of the dash.
Lavoy

[data]

I've finally got the rod assbly loose from the dash, and had to drill out the compression pins, but, I cannot get the handle off the rod. It appears as though it must screw off since there is a place to put on a wrench, but I need to know exactly which part screws off from which. The compression pin has also been removed from the handle housing, I have heated the piece with an lp torch, and squirted wd-40 in there, but no luck. I can see it would be possible to twist the end off the rod, and I don't want to do that. Does anybody have an answer?, Thanks.

[Lu47Dan]

Larry, I used a pittman arm puller to remove my throttle lever from the shaft. I had to heat the arm's hub many times to get it to break loose. I bought the pittman arm puller from Harbor Freight, thinking it might work. I was going to build a puller frame for my port-a- power but decided to try the puller first. I used 1/4" drive sockets to adapt the screw to the shaft.
Buy better penetrating oil, the only thing I use WD-40 for anymore is killing wasps. Kroil works very well, PB Blaster is better then WD is.
Cycle the heating with overnight soaking of the joint.
Dan.

[data]

Great info, thanks Dan, that puts me on the right track. My worry was that the rod might be threaded, but, now I know I can use a puller to get it off. I've had this machine for 36 years and this has never been apart. It's only the last 2 years that the throttle lost its' friction. Do you think I can use gasket cork to replace the originals?

[Lu47Dan]

The friction discs are available from Mother Deere for $6.68 each, you will need two.
Lavoy might stock them, but you will have to e-mail him for that answer.
The part number is M1860T, they are a composite material if the parts page is right.
Replace both the one under the lever and the one in behind the instrument panel.
I do not think cork would be worth the effort that it takes to get down to them.
Once renewed they might be good for another 34 years.
Dan

[data]

I just want to be clear about this...you're sure the shaft into the handle housing is not threaded?
I'm wondering because the handle housing has a flat part for a wrench, and because with all the heat and Kroil penetrent plus the puller maxed tight, it has not budged one iota.
I am apprehensive about putting too much pull with the puller and cracking the handle housing. I imagine, that is a cast iron piece.

[Lavoy]

Handle is absolutely not threaded onto the rod, it is a slip fit with a roll pin retaining it.
Lavoy

[Lu47Dan]

Larry, I had to heat the pee out of the levers hub with the pittman arm puller on it to get mine to budge, I mashed a couple of cheapee 1/4" drive sockets I was using as adapters. Once I had it hot I would smack the head of the draw bolt it shock the assembly. I was really frustrated by the time it finally started to move. Heat is your friend here, I melted the friction disc under the lever before I could get mine to budge.
Oxy/Acet. torch is what I used with a number 1 welding tip to concentrate the heat into the hub. I burnt myself a few times also. A big cresent wrench(24"), holding the puller from turning will also help. You could make a bar out of 1-1/4" tubing that you can clamp on to the puller also. If I had not had the cresent wrench here that is what I would have done.
It is press fit from the factory and seems to get tighter with age, probably from corrosion, but with some patience and enough heat it will come apart.
The hub on the lever has a lot of meat hiding behind it that has to be expanded before it will release. I will get a picture posted later today.
Dan.

[data]

Okay, thanks.
I'll perservere over the next few days and let you know what happens.

[data]

Okay, thanks.
I'll perservere over the next few days and let you know what happens.
Maybe I'll try some coca-cola.

[Lavoy]

There is at least as much lever going through the dash as is visible from the outside. If you still have the bracket bolted to the water outlet, you can squeeze against the throttle rod bracket with a water pump pliers and force the rod towards the dash compressing the spring and inch or so. This will expose more of the lever as far as getting heat on it. For heating something like this, I use a "rosebud" type heating tip. Get as much heat as possible in the shortest time on the lever itself. If you heat slowly, the heat transfers to the rod, and it expands at the same rate as the lever, so no gain. You need to get the lever glowing red in short order and get it moving before the rod itself has a chance to expand. Done more than I can count this way, only ever broken one rod off.
Lavoy