1956 Racine built large frame CASE 400 seat repair

This is a follow up to previous threads that show disassembly and a parts diagram:

how do I remove shaft from this seat torsion?????

and

Re: how do I remove shaft from this seat torsion?????

The following photographs show the broken parts and wear I found afetr taking everything apart:

The pivot bolt is severely pitted


One torsion spring rivet plate got chewed open


The boss broke out of the side plate


Both side plates had elongated holes at the end.


I can't see just bolting everything back together as-is. I'll do what I can to weld the boss back onto the side plate straight and fill/redrill the elongated holes. Be back with more photos when I'm done. Probably sometime tomorrow.

Sometime in the future I will see what I can do about getting a new pivot bolt and bushings but for now, these will have to do. Shouldn't be hard to replace any part ... once it's back together with these unseized pieces.

Do yourself a favor and do a search for coil over shocks and find 2 that are the the
correct length and strength and then fab up brackets to bolt to tractor and one to
bolt to seat frame. -------------------Loren

I'll probably end up doing that eventually Loren. I didn't see anyway to do that easily with shock/springs I could find and ordered the torsion rubber spring. For now, I already have it so it's going in. All the shock/spring units seemed way too long.

As far as i can tell this one was the original and I broke it about 6 years ago. I was sitting down with the seat in the flipped back position when it happened. Long legs !

Now that I know the rubber spring is a weak link. I'll be moving it all the way back in the slots this time, so I don't have to flip it back to be comfortable.

I weigh about 240 pounds. Usage is probably going to be maybe 100 Hours a year. All low speed. Mowing tall grass/weeds and clearing snow. How long do you estimate the stock rubber torsion spring will last ?

There are many coil-over shocks for minibikes and atvs listed on E-bay and Amazon that
are workable for that seat suspension arm. There is also room to mount them on an
angle with a fabricated"roster comb" bracket to adjust the ride height and load
reaction.-----------------------Loren

Loren, I hear what you are saying but instead my hands go about fixing this seat suspension. It will work for a while. Meanwhile ... once I am up and running again ... I will look into a coil-over arrangement that is cheap and easy.

Tomorrow, I finish painting the rear wheel clamps and put the wheel onto the tractor. That and putting the seat back together is all it needs now. The welding on the worn seat parts is done.

More grinding/shaping/carving/sculpting the weldments tomorrow and then I can reinstall the seat and suspension. It would really be a drag if the new rubber torsion spring lets go as soon as I put my weight on it.

The shift knob I got that was supposedly stock is WAY TOO SMALL for the shifter. Looks like 5/16" thread. The small end of the shifter is almost 1/2" in diameter. I'll live without it for now, Got the new boot on at least.

I may have a used spring like that. I bought a couple at a sale last year. I think one of them still has working springs.

So I have the spring. The rubber is a little ratty looking but they seem to have all their spring. I can barely move the
center pivot. The ears must have been worn like yours, they have new pieces welded over the ears and the holes appear to
be round. I also have that seat assembly with a spring that is shot, but the screw adjuster is there. Let me know if you
want to buy this used stuff. I will send you pictures.

Enclosed is the website of John's & Chris's, I got parts that were so close to OEM from them, for my early long nose "730". Haven't finished it yet, but will be soon and will take pictures. As a few others I ordered a new steering wheel also, going to look pretty sharp! I enclose the "730"



Untitled URL Link

Enclosed is some of the goodies I have put on my "730", you will see the seat suspension also in the goodies. I bought a steel seat from a "400" that will replace the current seat that I haven't had luck finding.

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(quoted from post at 05:32:29 11/05/19) Enclosed is some of the goodies I have put on my "730", you will see the seat suspension also in the goodies. I bought a steel seat from a "400" that will replace the current seat that I haven't had luck finding.
<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto40931.jpg">
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Click to expand...

Hi Ande, Thanks for the offer. I was able to weld the center of the side plate back into place and build up the corroded friction disc area on it and the pivot bolt. I think I'm ok for now but how much would you be asking for just the pivot bolt.

Also I am finding that the hole on the right hand side where the damper adjusting knob is, looks like it was made bigger than the hole on the left side. The pivot bolt is a loose fit in the right side. I think there is supposed to be a metal spacer or collar in there like a bushing that also fits part way into the knob.

Do you remember seeing a metal spacer or collar when the knob is off ? Also I'm trying to come up with something to push into the two holes on top of the cast piece the seat bottoms onto when it is all the way down. Something softer than banging down on steel against cast iron. I case I hit a big bump.

I see your seat spring seems to be missing the two friction discs as was mine. The two arcs are both both tilted in just like mine was. Probably from tightening the knob on the right side. At this point I'm trying to figure out what the friction discs are made of.

After thinking about it, I realize they are friction dampers or shock absorbers. The rubber provides the spring and holds the seat up. The front knobs adjusts the seat height, obviously. The side knob was a bit of a mystery to me at first. I realize now that it adjusts how much damping the suspension has. The friction dampers act to slow down the seat movement so it won't bounce up and down continuously and it's adjustable

The parts diagram shows the friction discs but I have not been able to determine what they are made of. I'm considering trying to cut a piece out of the sidewall of a bald tire. Either that or maybe a nylon or ABS disc. Something not to grabby and still strong enough to not get torn.

I put everything together and left the damper/friction knob loose. There is some friction already due to a slight misalignment of the side plate bushing. I'm sure that will wear away soon so I need to get something in there to do the job the frictions discs are supposed to handle.

Would you consider selling just the pivot bolt ? I was able to weld the hub/collar back into the side plate and build up the corroded friction surfaces. Added some to the pivot bolt also and field it to fit. Certainly none of it is a precision surface but strong at lest.

I notice your seat suspension is missing the friction discs. Mine had none either and both arcs on the suspension arm were bent inwards at an angle from overtightening the damper adjusting knob. Looks identical in that regard.

I just got back from an excursion trying to locate something to make frictions discs from. I assume it used to be some type of rubber/fabric composition. I have a couple of things to try. Some thick hard felt patches for underneath furniture legs and PVC sheet. As a last resort I'll cut the sidewall out of a bad tire and try that.

I'm hoping to have something in there for friction discs to prevent the seat from bobbing up and down constantly. If for no other reason a spacer in there will keep the arcs squared up. That should help prevent the nut holding the left end of the pivot bolt securely from spinning or working loose.

I also noticed what seems to be a problem with the size of the hole at the knob end. It's too big and seems to beg for a collar around the pivot bolt to hold it up level with the other end. Otherwise the knob does not want to seat squarely against the arc unless it is extremely tight which does not seem right.

I have that bolt with the adjusting wheel that goes through those donuts. It is on the seat so not sure what shape bolt is in till i take it off--if i get it off.

If nothing is seized, it should come out by first removing the left side nut with a split/lock washer. Then the pivot bolt should simply pull out to the right with the adjustment knob still attached.

Do you still happen to have the frictions discs also ?

Yes I have those. I will try to post some pictures but it might be later on today.

Here are the pictures. The good: The spring has plenty of spring, I tried to press down the center member with my
foot and it moved about an inch. The holes in the welded on ears look round. The bad: The weld job is pretty ugly,
though some grinding down would help. The bushings in the center are mostly gone one one side and I can't see it on
the other.

The bolt is a bit skanky and when I tried to put the nut back on it was stubborn. Threads need to be cleaned up. Since
this site isn't for buying and selling, send me an message if you are interested.

(quoted from post at 19:08:01 11/06/19)
The bolt is a bit skanky and when I tried to put the nut back on it was stubborn. Threads need to be cleaned up.

<img src="https://www.yesterdaystractors.com/cvphotos/cvphoto41061.jpg">

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Yes please PM me regarding the bolt. I could not PM you for some reason. My pivot bolt is in much worse condition even after some repairs. It's doing the job though .. for now.

I made two discs out of 1/16" mild steel - 16 Ga. A little smaller than the diameter of the torsion spring. Drilled holes to clear the pivot bolt.

The 16 Ga disc and a felt pad (3/16" thick by 5" diameter) are on the right side. The left side has the other mild steel disc and a PVC disc (1/8" thick by 5"). That's the best fit I could get from the materials I had gathered up.

Both arcs had to be tweaked outward so they were square to the suspension arm. I'm sure the knob on the right had been over tightened at some point after there were no more friction discs. The friction discs I made up went in fairy smoothly after straightening out the arcs.

I tightened the front knob until the seat went down only a little when I sat on it. I tried bouncing up and down on the seat. What fun !

I tightened the knob on the right end of the pivot bolt until the seat did not bounce up and down. When I sit, the seat goes down a little. No bounce. When I get up, the seat raises back up to full up. I'll see how long it lasts.

So did you make some springs? Anyway that bolt is available. Where are you located? Do you have paypal? I will figure out shipping. I would like
to clear $3 on it if possible.
Regards
Ken Hansen

Ken, email me directly please

[email protected]

Jeff Garber

I had already bought a new torsion spring. It's all installed but a better pivot bolt than mine would be good to put in. Then It would be worth chasing down some new bushings which I never realized are in there until doing all this.

Here are a couple of photographs showing the friction discs in place. The one one the right side is the 1/16" steel disc and a 3/16" thick felt disc. The one on the left also has a 1/16" steel disc and a 3/32" thick PVC disc.

the steel plates are close to the same diameter as the side plates that are riveted to the torsion spring. The friction discs are about 1/4"-1/2" smaller diameter.

After working the tractor for a few hours the past couple of days, the seat/rubber torsion spring is still supporting me and the damper/friction discs seem to be holding the adjustment well. Best thing is they have not become torn up and falling out already which is about what I half expected to happen. I'm pleased they are not ... yet.

I'm thinking if I had friction discs in place all along, the original rubber torsion spring may have lasted even longer. Anyone want to venture a guess as to how long I should expect to use the seat, before this new aftermarket one fails ?

Look like those rubber springs are still in stock for your tractor. The ones for the 300/350 are back
ordered.

yes, I was able to get the new rubber torsion spring for my 400. It did the job with the friction discs I made. It has not broken yet after about 4 hours in the seat.

It will get more use in the coming months and especially next spring/summer. I'll report back again to let everyone know how long it takes before the rubber let's go again.

Any predictions ?

Just a quick note to say the seat suspension rubber has not broken after doing some work for me and a bit of a rest and then a little more work just recently. So far, so good nothing has come apart and the ride height and friction adjustments are very easy to dial in.