Going to look at a JD 350 Sickle Mower

kopeck

Member
Hi,

I'm going to take a look at a JD 350 mower that's near by. I've been hoping to upgrade to a wobble box type mower, right now I have a Massey Ferguson #32 pitman type. I use it to trim around my fields and ditches all of which are banked pretty well so the pitman gets a little harry at times.

From what I've read the weak point on these is the pin & arm that attaches the wobble box to the knife head. Any slop is a cause for concern as the replacement parts are very sepndy. Is there anything else on the box I should be looking at as well? Any other gotcha areas in general?

As an aside, is there any reason you couldn't bore the hole in that arm oversized and make a new pin to match the hole. Obviously the bottom of the pin would have to stay the same size to fit in the bearing in the knife head but I do have a mill and a lathe....

Thanks!

K
 
Turn the flywheel to put the knife in mid stroke. Then see how much backlash is in the mechanism before the knife
moves each direction. This checks the wear in the bearings of the wobble joint.

Check the cutterbar bolts/spacers to the drive head. Someone may have cobbled that area.
 
(quoted from post at 07:17:19 09/11/20) Turn the flywheel to put the knife in mid stroke. Then see how much backlash is in the mechanism before the knife
moves each direction. This checks the wear in the bearings of the wobble joint.

Check the cutterbar bolts/spacers to the drive head. Someone may have cobbled that area.

Thanks!

How much backlash is acceptable?

K
 
Here's a photo of the bottom side of the "wobble box" where the cutter bar mounts.

<img src = "https://i.imgur.com/Pqemh7J.jpg">


The bottom end of the pin that commonly wallows out the housing (or the housing breaks where it's clamped) can be seen just below the "stud" in the photo. It is the lower pivot pin for the arm the sickle drive arm. If you look closely you can see the cross bolt that clamps the pin tightly into the housing.

Once that pin works loose and the housing wears or breaks it's a $1200+ fix.
 
OK, so it's not the pin that I was talking about earlier though it's the same idea.

Is there anyway to test for slop with out pulling the culler bar off (which isn't practical).

I'm starting to get a bit weary of these 350s all of a sudden. The price is pretty good on this one but it seems that could change in a heart beat. I know they all have their expensive bits but there seems to be a lot of them on this model.

K
 
(quoted from post at 08:18:38 09/11/20) OK, so it's not the pin that I was talking about earlier though it's the same idea.

Is there anyway to test for slop with out pulling the culler bar off (which isn't practical).

I'm starting to get a bit weary of these 350s all of a sudden. The price is pretty good on this one but it seems that could change in a heart beat. I know they all have their expensive bits but there seems to be a lot of them on this model.

K

If you remove the pin connecting the drive arm to the knifehead, then try to move the drive arm left and right and up and down you will be able to feel lots of movement if the pin in question has worn loose in the main casting.

If it's real bad the arm will be able to be moved up and down a LOT.

Of course. ANY looseness there is bad and just going to get worse and if the problem has just started it may not be noticed without dropping the cutterbar and having a close look.
 
(quoted from post at 08:38:52 09/11/20)
If you remove the pin connecting the drive arm to the knifehead, then try to move the drive arm left and right and up and down you will be able to feel lots of movement if the pin in question has worn loose in the main casting.

If it's real bad the arm will be able to be moved up and down a LOT.

Of course. ANY looseness there is bad and just going to get worse and if the problem has just started it may not be noticed without dropping the cutterbar and having a close look.

Let's hope that pin comes out! So ideally the only movement at the knife head drive arm should be in and out, zero side to side or up and down.

Thanks, this really helps. Buying anything used is a risk of course but the idea that one or two parts that are known to wear and cost more than the whole machine probably should makes you want to know what you're getting into!

K
 
(quoted from post at 09:28:19 09/11/20)
(quoted from post at 08:38:52 09/11/20)
If you remove the pin connecting the drive arm to the knifehead, then try to move the drive arm left and right and up and down you will be able to feel lots of movement if the pin in question has worn loose in the main casting.

If it's real bad the arm will be able to be moved up and down a LOT.

Of course. ANY looseness there is bad and just going to get worse and if the problem has just started it may not be noticed without dropping the cutterbar and having a close look.

Let's hope that pin comes out! So ideally the only movement at the knife head drive arm should be in and out, zero side to side or up and down.

Thanks, this really helps. Buying anything used is a risk of course but the idea that one or two parts that are known to wear and cost more than the whole machine probably should makes you want to know what you're getting into!

K

There won't be "zero" play, but shouldn't be much.

I wish I had exact numbers for that, I've worked with those mowers for a long time, and it's sort of a judgement/feel thing.
 
There won't be "zero" play, but shouldn't be much.

I wish I had exact numbers for that, I've worked with those mowers for a long time, and it's sort of a judgement/feel thing.


So something like enough movement to allow things to go where they need to but not excessive play.

I'll do my best. I have a knack of bringing home clunkers, I hope I can avoid that this time around.

K
 
"[b:654c4848f0][i:654c4848f0]Any slop is a cause for concern as the replacement parts are very spendy[/i:654c4848f0][/b:654c4848f0]"

Agree.

Cycle the knife as far out as possible towards the outer shoe.

Take a look at the photos below.

cvphoto55562.jpg


cvphoto55563.jpg


Move the knife further outward away from the knife drive yoke.

This should give plenty of room to check "[i:654c4848f0]slop[/i:654c4848f0]" in all directions.

"[b:654c4848f0][i:654c4848f0]Any other gotcha areas in general?[/i:654c4848f0][/b:654c4848f0]"

Take a look at the photo below.

cvphoto55564.jpg


Make sure there are no cracks in the cutterbar.

Hope this helps.
 
So here's what I found.

I couldn't lay the bar down, there wasn't enough room so I really couldn't pull the pin and test the arm/housing. What I could do is grab the large cast section that towards the rear and that would move up and down 3/16" easily. I'm not sure they're related. I did take a video of the movement that you can see here:

https://youtu.be/wJ3RgKn8Osc

As far as back lash there was some for sure, it was hard to measure but there was a pause as the knife reversed direction. Everything felt smooth though, I tested the thing the best I could with the cutter bar sitting on my shoulder.

The machine doesn't look beat up at all but it does look like it's been used. It's missing it's swath board and half of the PTO. They were going to look around for those parts but I suspect they're gone.

I'm really not sure what to think. The price of the JD parts I've looked up really scares me though. I'm sure NH &amp; IH parts are not given away either but that green paint seems to command a premium.

K
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top