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CHS Ricardo Cavallero S.R.L manual steering boxes


bkahler

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Now I see what you're talking about on the bearing shell or race...I've seen this on chinese and Indian gearboxes for agricultural applications that cannot be serviced but only replaced when bearings go out, instead of buying 50 bucks in brgs + seals for servicing, the gearbox is replaced as a unit for over 500...twice I've had to tear down gearboxes and show disbelieving neighbors that there is no slot cut in the casting for race removal, maybe an angle grinder can cut one out but there's not adequate access for that tool either...saw it earlier this year on a John Deere small tractor hub also when bearings were being packed...maybe that shell can be cut out with an OA torch but leaving it be since it's in good shape is a good call ?

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1 hour ago, JBNeal said:

Now I see what you're talking about on the bearing shell or race...I've seen this on chinese and Indian gearboxes for agricultural applications that cannot be serviced but only replaced when bearings go out, instead of buying 50 bucks in brgs + seals for servicing, the gearbox is replaced as a unit for over 500...twice I've had to tear down gearboxes and show disbelieving neighbors that there is no slot cut in the casting for race removal, maybe an angle grinder can cut one out but there's not adequate access for that tool either...saw it earlier this year on a John Deere small tractor hub also when bearings were being packed...maybe that shell can be cut out with an OA torch but leaving it be since it's in good shape is a good call ?

If there is enough room to get the electrode in, one can lay a weld bead with a stick welder onto the race.  When it cools it will be loose and cam be removed.  The weld shrinks the race a lot.

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23 hours ago, JBNeal said:

Now I see what you're talking about on the bearing shell or race...I've seen this on chinese and Indian gearboxes for agricultural applications that cannot be serviced but only replaced when bearings go out, instead of buying 50 bucks in brgs + seals for servicing, the gearbox is replaced as a unit for over 500...twice I've had to tear down gearboxes and show disbelieving neighbors that there is no slot cut in the casting for race removal, maybe an angle grinder can cut one out but there's not adequate access for that tool either...saw it earlier this year on a John Deere small tractor hub also when bearings were being packed...maybe that shell can be cut out with an OA torch but leaving it be since it's in good shape is a good call ?

 

 

Yep, I've noticed that with my Kubota tractor and various attachments.  I'm not sure where Japan gets it's steel now days but just about everything on the Kubota is heavily rusted.  

 

22 hours ago, kencombs said:

If there is enough room to get the electrode in, one can lay a weld bead with a stick welder onto the race.  When it cools it will be loose and cam be removed.  The weld shrinks the race a lot.

 

I sold my stick welder years ago and make due with a Hobart mig welder and it would be iffy getting the stinger inside the housing.  If this was a high rpm motor I'd be more concerned about the bearing race.  I've played with the new and the old bearings and the feel is the same with whatever combination of parts I try.  I guess worst case is I have to pull it apart to do something about the race but I'm comfortable with the option I'm going with.  Of course, my fingers and toes are cross.....!!

 

Brad

 

 

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On 9/6/2020 at 6:43 PM, kencombs said:

If there is enough room to get the electrode in, one can lay a weld bead with a stick welder onto the race.  When it cools it will be loose and cam be removed.  The weld shrinks the race a lot.

 

Good idea. That's how valve seats are usually removed from head castings as well. 

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Had to take a couple of steps back and fix a problem I neglected to resolve prior to welding the pin in place.  The issue I noticed after I originally pressed the pin in place (prior to welding) was a "slight" catch of the sector wheel when spinning it.  The catch really didn't seem all that bad, you could spin the wheel for multiple revolutions and then once in a while you'd feel a slight catch and have to push past it.  My thought at the time was it would wear in during use and not be a problem.  Wrong, this was mistake number 2 ? I'll get to mistake number 1 in a minute.

 

After doing a trial fit of the steering gearbox and rotating the steering column shaft you could feel the catch.  As I tried to adjust the sector shaft closer to correct tolerance the catch got worse.  It was at that point I figured I better fix the problem now.  

 

It took me about 20 minutes with a dremel and a pin point cutter to grind the weld off one end of the pin.  Not as bad as I thought it would be although I'd prefer not to do it again!

 

Now that I had it apart I needed to determine what the problem was.  The first thing I did was to measure the thickness of each spacer washer.  They mic'd out at .0795" each.  The wheel mic'd at .9765" for a total width of 1.1355".  Next I measured the overall width of the old wheel and spacer washers, they mic'd out at 1.1345", so there was a grand total of .001" difference between the two sets with the new set being wider. 

 

Back when I gave the spacer washers and roller to the machinist I included the sector shaft as well so he could fit them in place.  I did not include the press pin figuring it wouldn't be needed.  That was mistake number 1.  When I picked up the parts he mentioned that the walls inside the sector arm where the roller goes weren't quite parallel and and he did some light filling to alleviate some of that, enough that the spacers and roller fit smoothly.  The shaft itself measures .442" in diameter.  For test fitting in his shop I believe he probably used a 7/16" or .4375" shaft.  After testing with a 7/16" shaft myself, the .001" extra in width was not noticeable at all.  So......

 

I spent about an hour filling the opening in the sector arm to bring the walls back to parallel.  I used a telescoping mic to check fit by setting it on the widest point and filing both sides until the mic would fit where the spacer washers were located.  I won't say the walls are perfectly parallel but the roller now fits properly and rotates very smoothly.  I've rewelded the pin in place and am now ready to start assembling the gearbox.  

 

Keep in mind, none of the above was a fault of the supplied kit from CHS.  It was all because I didn't think things through during the assembly process.  Live and learn.

 

Evan, hopefully you'll learn from my mistake and make 100% sure the wheel spins smoothly prior to welding the tips of the pin :)

 

Brad

 

 

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20200910_142145x.jpg.8ab69e0db56a6f02e030971f62cd1ead.jpg

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I have a couple of questions on steering box rebuilding.  There are two cover plates, one for the sector shaft and one for the worm shaft.  The sector shaft uses a paper gasket.  I would normally use permatex #2 non hardening sealant on paper gaskets.  Is this acceptable for this gasket?

 

On the worm cover plate it uses metal shims.  I would normally seal this type of shim with a light coat of permatex #2 non hardening.  Is that recommended for this application?

 

Thanks!

 

Brad

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I used RTV black on both plates with no paper gasket, filled with JD corn head grease...hasn't leaked yet...I look at sealing the gearbox as similar to sealing an axle differential as materials and function are similar...on the next one I do, I'll go with gear oil RTV as a tube of that stuff goes a very long way :cool:

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13 hours ago, JBNeal said:

I used RTV black on both plates with no paper gasket, filled with JD corn head grease...hasn't leaked yet...I look at sealing the gearbox as similar to sealing an axle differential as materials and function are similar...on the next one I do, I'll go with gear oil RTV as a tube of that stuff goes a very long way :cool:

 

What did you do about sealing the metal shims?

 

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I stacked the shims on the bottom plate then laid a RTV 1/8" bead along the inside shim edge,  making sure the bead overlapped the shim and the plate, let it skin over for a few minutes, assembled it on the bench with bolts finger tight, then the next day torqued 1/4 turn...doing this puts RTV over the inside edges of the shims to prevent leaks, but allows for disassembly in the truck without destroying those thin shims :cool:

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22 hours ago, JBNeal said:

I stacked the shims on the bottom plate then laid a RTV 1/8" bead along the inside shim edge,  making sure the bead overlapped the shim and the plate, let it skin over for a few minutes, assembled it on the bench with bolts finger tight, then the next day torqued 1/4 turn...doing this puts RTV over the inside edges of the shims to prevent leaks, but allows for disassembly in the truck without destroying those thin shims :cool:

 

Ok, that makes sense.  I'll see if I can locate some gear oil rtv at the local parts stores.  If they don't have it then it will be Amazon and a week delay.

 

Thanks!

 

Brad

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55 minutes ago, jerseycj8 said:

Brad - I received my kit this past week, but sorry to say that I will not be using.....until you are completely done and sharing all of your trials/tribulations!!!!  I am cheering you on tho.

 

You're a smart man.....!

 

I think the rest of the work is just normal assembly type work.  I picked up the gear oil rtv yesterday afternoon and possibly today but more likely early this week I'll do the final assembly.  

 

Brad

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Ok, the steering gearbox is assembled.  The final product feels really good.  I did however make mistake #3 when I welded the ends of the pin the second time around.  I didn't find out about the problem until I had the sector shaft in place and found that I couldn't rotate it through the full range and the more I tried the more the sector wanted to bind in the housing.  It took me a bunch of times tapping the sector arm out of the housing, recentering it and trying again. 

 

Finally on one of the attempts I noticed that it seemed to be in the same spot (duh!) so I pulled the sector back out again and looked closer.  It turns out when I welded the ends of the pin I built the weld up to high and the end of the pin was catching on the edge of the casting inside.  I guess there is a reason for the curved grinding that was done on the sides of the sector arm.

 

Pictures of the pin before grinding:

 

20200914_181723x.jpg.549d7985591f93bf0da21757a9ce119b.jpg

20200914_181740x.jpg.bc95ce41c809e57e17f4c008998be79b.jpg

 

Pictures of the pin after grinding:

 

20200914_182826x.jpg.65e12423cb771d03661d85257267aff5.jpg

20200914_182829x.jpg.2be8729c4f4e300004b4bc34d8dea742.jpg

 

 

The fix was to tap the pin all the way to one side, grind down the top of the weld bead, tap the pin to the opposite side and grind the bead on that side.  I managed to grind enough so that if the pin was maxed out to one side it wouldn't bind.  After solving that problem the rest of the assembly went really smooth.

 

Here's a couple of pictures installing the worm:

 

20200914_173557x.jpg.ff483dfddd2c595510fd33dd6eb53ecb.jpg

20200914_174033x.jpg.8f2912d45189a34bd5a106bfa12301b4.jpg

 

 

The steering shaft can rotate approximately 4-1/4 turns lock to lock.  I made a mark at the 2-1/8 point and I can definitely tell as I'm adjusting the sector arm in and out where the high point of the worm is.  Right now I have it set to where I think should be but I'm not sure just how much drag should be felt when the steering wheel is centered.  More research is needed.

 

So the lesson learned this time was to make sure the ends of the pin are ground down to allow for clearance inside the casting.  I can't imagine what would have happened if I was driving and the pin decided to shift far enough to contact the casting.  The outcome would probably not be good.

 

I still need to put the dust seal in place, put the outer tube in place and add the cornhead grease.  I'm going to wait on the grease until the whole assembly is mounted in the truck. 

 

Brad

 

 

 

Edited by bkahler
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  • 4 weeks later...
On 9/14/2020 at 7:49 PM, bkahler said:

 

Ok, the steering gearbox is assembled.  The final product feels really good.  I did however make mistake #3 when I welded the ends of the pin the second time around.  I didn't find out about the problem until I had the sector shaft in place and found that I couldn't rotate it through the full range and the more I tried the more the sector wanted to bind in the housing.  It took me a bunch of times tapping the sector arm out of the housing, recentering it and trying again. 

 

Finally on one of the attempts I noticed that it seemed to be in the same spot (duh!) so I pulled the sector back out again and looked closer.  It turns out when I welded the ends of the pin I built the weld up to high and the end of the pin was catching on the edge of the casting inside.  I guess there is a reason for the curved grinding that was done on the sides of the sector arm.

 

Pictures of the pin before grinding:

 

20200914_181723x.jpg.549d7985591f93bf0da21757a9ce119b.jpg

20200914_181740x.jpg.bc95ce41c809e57e17f4c008998be79b.jpg

 

Pictures of the pin after grinding:

 

20200914_182826x.jpg.65e12423cb771d03661d85257267aff5.jpg

20200914_182829x.jpg.2be8729c4f4e300004b4bc34d8dea742.jpg

 

 

The fix was to tap the pin all the way to one side, grind down the top of the weld bead, tap the pin to the opposite side and grind the bead on that side.  I managed to grind enough so that if the pin was maxed out to one side it wouldn't bind.  After solving that problem the rest of the assembly went really smooth.

 

Here's a couple of pictures installing the worm:

 

20200914_173557x.jpg.ff483dfddd2c595510fd33dd6eb53ecb.jpg

20200914_174033x.jpg.8f2912d45189a34bd5a106bfa12301b4.jpg

 

 

The the steering shaft can rotate approximately 4-1/4 turns lock to lock.  I made a mark at the 2-1/8 point and I can definitely tell as I'm adjusting the sector arm in and out where the high point of the worm is.  Right now I have it set to where I think should be but I'm not sure just how much drag should be felt when the steering wheel is centered.  More research is needed.

 

So the lesson learned this time was to make sure the ends of the pin are ground down to allow for clearance inside the casting.  I can't imagine what would have happened if I was driving and the pin decided to shift far enough to contact the casting.  The outcome would probably not be good.

 

I still need to put the dust seal in place, put the outer tube in place and add the cornhead grease.  I'm going to wait on the grease until the whole assembly is mounted in the truck. 

 

Brad

 

 

 

Brad - Got a local machine shop to do the heavy work; however, the reaming of the bushings looked like my dog chewed them from the inside out.  As such, I found ID bushing material that they milled OD down to spec and I installed today.  Question - I installed the sector shaft seal, but having second thoughts if correct orientation.  Attached is photo.  Is this correct?

IMG_13102020_185638_(1080_x_1080_pixel).jpg

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23 minutes ago, bkahler said:

I don't really have any suggestions other than take it so and and easy.

 

I would think that seal would be available at a good bearing supply house.

 

Good luck.

Had an extra one in the parts bin and installed with the rubber lip facing in towards the gearbiox.  Whew.

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  • 5 weeks later...

I probably should post an update to this thread.  The gearbox rebuild is complete and seems to be a quality kit.  There is virtually no play in the steering box now and with the new parts in the rest of the steering system it should drive like a new truck.  The only thing left is to actually do a test drive.  Once that happens I'll post one last time with an update.

 

Brad

 

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  • 9 months later...

I took a chance and got a kit from dennis carpenter ford parts Part #: 78-3548-KIT.   Everything fits except the bushings and top sector gasket.

1st - to get the upper worm race out I used a long 1/4" carriage bolt, fed the head down the hole where the steering tube goes and just caught the edge of the race with the head of the bolt and tapped it out.

2nd - to get the worm off I just pressed it. Alternatively you could just cut it along the length and whack it with a chisel.

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For me, setting the pin was the most difficult part of the job.  I ended up welding the top of the pin on each end to create a ridge.  Wasn't the prettiest but it was functional.  If I had to do it over again I might heat the tip of the pin cherry red and hammer it enough to deform the end.   The goal is to keep the pin from sliding out while in operation.

 

If you do weld like I did take great care to ensure the overall length of the pin is such that when rotating the steering shaft the pin can't slide to one side and jam into the case.  

 

On my first attempt at welding this happened to me.  If I hadn't caught that issue and finished reassembling and then drove the truck, it's possible the pin could have shifted while driving and the steering would have locked up on me.

 

Good luck!

 

Brad

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