4640 steering

[young tractor]

Hi guys. I’m digging into the telescoping steering on my jd 4640 tractor. Somehow the bracket on the main tube cracked and broke off. I’m guessing it’s from people pulling themselves in the cab over the years. Since I’m in there I would like put a new upper and lower seal in and new needle bearing. I figured out the lower seal in the metering box. I can’t figure out how to get the seal out the top of the tube that’s just below the steering wheel. The bushing is up against that. Should the bushing have come out with the shaft? Does the seal come out the bottom of the tube?
Also I only found a small piece of the needle bearing left when I took it apart. Obviously someone had it apart and didn’t put a new bearing in. I can’t figure out by the parts diagram where the bearing goes. Does it go on top of the big washer on the shaft?I posted a couple pics to see if that helps you understand what I’m talking about. Thanks for any advice.

 

[620 John]

Should be able to dig the oil seal out with an o-ring pick. It's just an all rubber lip seal. The bushing is just a snug fit in the steering column that can be removed or installed with a small hammer and bushing driver or maybe a socket if you're careful. Your new column should come with a new bushing installed if I remember correctly.

The needle bearing #7 gets sandwiched between two washer (#6) and all 3 pices sit on top of the sleeve #8. The top #6 washer will sit on the inside of the column tube right below the bushing. I'm guessing one of the #6 washers is what's sitting on top of the sleeve in your 3rd picture. The other washer might still be stuck inside the column or wasn't reinstalled the last time.

Some additional advise:

Make sure you check your new steering column over carefully for any bends or warps in the plate that's welded to the tube. I had one that was either dropped in shipping or got too hot when it was welded together. Put it all together and the damn thing was locked up because the pump housings were clamped unevenly due to the warped column.

I also recommend finding a set of alignment dowels for the housings when going back together as explained in the service manual. I've never tried doing one without the dowels and even with the dowels some of them can be a little stiff when you go back together with it.

Make sure you check the plastic bushing on the steering shaft for any excessive wear. If the bushing is wore and the shaft is allowed to flop around you'll be taking it apart again when it start leaking.

I also use an aerobic gasket maker like this on the gasket/shims for the pump housing. Use just a VERY light film of this on the housing before laying down the shim. Use something like a credit card to smooth out the shim. https://next.henkel-adhesives.com/u...tite-515/BP000000153466/variation/135479.html

Speaking of those shims when you go to your dealer to pick up parts I highly recommend opening the cardboard package that contains the shims before you take them home. More than once I've had to get a another set of shims because they were wrinkled up in the package and were impossible to flatten out.

 

[young tractor]

Should be able to dig the oil seal out with an o-ring pick. It's just an all rubber lip seal. The bushing is just a snug fit in the steering column that can be removed or installed with a small hammer and bushing driver or maybe a socket if you're careful. Your new column should come with a new bushing installed if I remember correctly.

The needle bearing #7 gets sandwiched between two washer (#6) and all 3 pices sit on top of the sleeve #8. The top #6 washer will sit on the inside of the column tube right below the bushing. I'm guessing one of the #6 washers is what's sitting on top of the sleeve in your 3rd picture. The other washer might still be stuck inside the column or wasn't reinstalled the last time.

Some additional advise:

Make sure you check your new steering column over carefully for any bends or warps in the plate that's welded to the tube. I had one that was either dropped in shipping or got too hot when it was welded together. Put it all together and the damn thing was locked up because the pump housings were clamped unevenly due to the warped column.

I also recommend finding a set of alignment dowels for the housings when going back together as explained in the service manual. I've never tried doing one without the dowels and even with the dowels some of them can be a little stiff when you go back together with it.

Make sure you check the plastic bushing on the steering shaft for any excessive wear. If the bushing is wore and the shaft is allowed to flop around you'll be taking it apart again when it start leaking.

I also use an aerobic gasket maker like this on the gasket/shims for the pump housing. Use just a VERY light film of this on the housing before laying down the shim. Use something like a credit card to smooth out the shim. https://next.henkel-adhesives.com/u...tite-515/BP000000153466/variation/135479.html

Speaking of those shims when you go to your dealer to pick up parts I highly recommend opening the cardboard package that contains the shims before you take them home. More than once I've had to get an another set of shims because they were wrinkled up in the package and were impossible to flatten out.

Thank you for your in depth response