420 clutch problem

panhead · Post by **panhead** » Mon Jan 21, 2013 1:42 pm

I have a JD 420.
It was a wreck, I finally have most everything fixed.
I've had the whole thing apart, including the engine.
Now the engine run's good, but I can't get it to move.
There is tension on the clutch pedal, from the time you start pushing it in.
I know about the adjusting nut, on the side.
I've got it loosened up, but I can only get about a 1/6, of a full rotation on the adjusting screw itself.
My question is:
Should the screw have a wider range of motion, or could I have hosed something up, attaching the engine to the bellhousing?
I sure don'e want to pull the motor again.
Thanks
Jim

Post by **Lavoy** » Mon Jan 21, 2013 4:36 pm

IT should rotate at least 180 degrees.
Lavoy

panhead · Post by **panhead** » Mon Jan 21, 2013 5:09 pm

Lavoy;
Would there have been any way to get that adjusting cam in there backwards,upside down, or off 180 degrees?
I don't want to pull that engine, just to find out there's nothing wrong.
There's pretty good tension on the clutch pedal, could that keep me from being able to adjust the clutch stud?
Do you have any trick's for me to try?
This has been a frustrating project, and I'd sure like to see it move.
Thank's again
Jim

DukeofDeere · Post by **DukeofDeere** » Mon Jan 21, 2013 7:42 pm

Did you replace your pressure plate?
Sounds like it may be way out of adjustment.

Duke

Post by **Lavoy** » Mon Jan 21, 2013 8:00 pm

Push on the clutch pedal while you are trying to rotate the adjuster, see what it feels like. Really no way to get it in there wrong, nothing really to bind on.
Lavoy

panhead · Post by **panhead** » Mon Jan 21, 2013 8:51 pm

The whole clutch/flywheel assembly was rebuilt, and set-up by Lakehead Clutch in Duluth, Minnesota. I'm figuring they did it right.
I can only get about 30-40 degree's of play on the adjusting cam, I figure this is where my problem is at.
I had the clutch pedal pushed in, and It didn't seem to make it easier to turn.
I suppose I could double nut that adjusting cam, leaving a little play, maybe if I can get a little more leverage on it she'll come loose?
Hard to get any leverage with a 7/16ths wrench.
One more observation: When you look into that observation hole above the clutch adjusting cam, is that the grease zerk, is closer to the back of the hole.
Jim

whiteclipse16 · Post by **whiteclipse16** » Tue Jan 22, 2013 7:03 am

Panhead, I'm no pro with a 420, but there may be some other things you can look at and others can correct me if I'm wrong.
You may be able to pull the shifter off the tranny and see if you input shaft is spinning.
If it is spinning that would tell me the clutch is functioning properly.
If you input shaft is spinning then try pulling an inspection cover to see the ring gear and see if that is spinning.
I'd say pull the inspection covers on the steering clutches but it seems pretty hard to believe that both steering clutches would be slipping/not turning.
Just some things to try if you haven't already, to possibly save you from pulling the engine.

Post by **Lavoy** » Tue Jan 22, 2013 9:09 am

It is possible that you don't have any more adjustment than that. Did you set the pressure plate fingers with the JD7 gauge prior to remounting the engine?
Lavoy

DukeofDeere · Post by **DukeofDeere** » Tue Jan 22, 2013 9:55 am

How much free travel do you have on your clutch pedal?
Is this an early -100000 machine or late 100000?

Duke

panhead · Post by **panhead** » Tue Jan 22, 2013 10:28 am

It's a later model, 115,000.
No free travel at the clutch, it's under tension all the time.
When I got the clutch back, everything was mounted to the flywheel, all I did was bolt up the flywheel, and aligned the pilot shaft, with a plastic gauge. They told me to adjust nothing, just mount it up.
I'm thinking about pulling the dust cover off, at the bottom of the bell housing, will I be able to see the yoke, and the the adjusting cam?
Thanks again
Jim

Post by **Lavoy** » Tue Jan 22, 2013 4:05 pm

Sorry to be the bearer of bad news, but your pressure plate is out of adjustment I will bet. Never install a pressure plate in one of these without adjusting the fingers. I know what your rebuilder says, but he is incorrect. His bench that he sets them on has no relationship to a 420 crawler in specific, and will almost always be wrong.
The pressure plate setting procedure is listed in the FAQ's section.
Lavoy

notmeu · Post by **notmeu** » Tue Jan 22, 2013 6:36 pm

Lavoy wrote:Sorry to be the bearer of bad news, but your pressure plate is out of adjustment I will bet. Never install a pressure plate in one of these without adjusting the fingers. I know what your rebuilder says, but he is incorrect. His bench that he sets them on has no relationship to a 420 crawler in specific, and will almost always be wrong.
The pressure plate setting procedure is listed in the FAQ's section.
Lavoy

I think a lot of us has been there and done that the hard way. That clutch setup gauge is one of those best tool in your toolbox kind of item.....

DukeofDeere · Post by **DukeofDeere** » Tue Jan 22, 2013 7:08 pm

Lavoy has it right.
Fingers are not being released.
Clutch is free spinning.
Sounds like where I've been before with another machine.
Could still pull the trans cover and see if anything is turning....

Duke

440 iron popper · Post by **440 iron popper** » Wed Jan 23, 2013 7:24 am

I think Lavoy got it. I had the flywheel machined and put a new clutch disk and pressure plate on mine as well. I had the gauge. It is surprising how much I had to lower those fingers on the pressure plate to be correct. Fingers too high would explain the lack of freeplay. Without the adjustment, The contact between the throwout bearing and the pressure plate would almost happen when you bolt the engine to the clutch case...

I had this question... Why they are not preadjusted? I guess those plates would fit several model of machines and you have to tune it for your application.

vtjoe · Post by **vtjoe** » Wed Jan 23, 2013 7:48 am

as i have explained to my daughter on more than one occasion, mechanical work is generally simple but deadly accurate------ if you get a 97% score on most school tests, you get an A In mechanical situations you still fail!!!
pull the motor and set up the clutch!!! with the gauge. it makes all the difference and then you get 100% job well done A+

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