My 1971 521

[d.p]

7 minutes ago, mainer311 said:

The o-ring rides on that heavy chamfer. It’s called a 3-point seal. Next time, McMaster is a decent source for o-ring stuff.

 

1295N269

 

 

I saw them there as well and only ordered the Amazon ones cause I had points.  McMaster would have probably been here quicker too. 

[d.p]

Can someone explain to me what stops the worm gear from blowing out the bottom of the steering box?  I ask because I watched @mklotz70 videos and he mentioned it as well and I am not clear on how it works.  

There are 2 bosses inside the gear box that I assume stop the pitman arm gear(?) in each direction.   The worm assembly turns that gear up and down in whatever direction I turn the wheel and when it reaches either boss that is where it stops.  But I was able to continue turning the wheel enough to push the steering worm out the bottom of the box and I assumed that was because the bottom bearing was dislodged.  So while I await new bearings installed the top bearing in the bottom (no bearing on the top) just so I could see how it sits and I could just as easily blow it out again.  I noticed the same thing in Mikes videos.  

 

So if I have both bearings installed, top plate installed and the column bolted to the steering box is that what keeps it all in place? 

 

 

 

 

[mklotz70]

I don't have time to repeat my answers on YT....maybe a bit later...weekend?.....unless you can copy/paste them here.....if they're actually the info you needed.  

 

I just wanted to point out that when you put the new bearing in, put grease on it to hold it in place while you put the shaft in.  The 90w gear lube will dissolve the grease over time and it should not hurt anything by doing that.  It's one of those "old timer" tricks I learned long time ago....from and old timer. lol

 

Also.....normally, I would say that you need to keep the races matched with the bearings...but in this case, I would personally not try to change the races.  I would put it together with the grease ....just the new bearing (balls and cage) with the existing races and see how it feels.  Changing the races would be quite the nightmare!! 

 

Did you already come across this ratsun page.  There's some extra pics from my photo bucket here....one of the steering box diagram that shows the size difference between the hole and the nut.   

 

 

[d.p]

Thanks Mike.

 

Quote

That was an exaggeration. It would take a huge amount of pressure and it would probably have to break the casting since the hole in the end (covered with a pressed in cap) is not big enough(I don't believe) for the ball nut to go through. It's been years since I've looked at it. Since you've just recently pushed the cap out, I'm guessing you know better than I do. 😉 The steering wheel being mounted at the other end would stop the shaft from coming out the end, even if you could force the nut past the end of the screw. You had a special case since you didn't have the wheel on. The bearing would also stop it in normal use unless is broke apart.....which is pretty unlikely.

 

Lol I should know better but I don't.  😞  Maybe I will once I have 2 working bearings. 

 

I can only assume with the bearing cage not being seated with the wheel attached is enough to allow the worm gear push the bottom cap out?  Because that is exactly what happened.  I noticed that the worm gear assembly 'backed out' towards the cab (wheel moved away from the column) right before it pushed that bottom cap out.   It was like it was pushing against the top or bottom of the gear box past the boss stops.  It was then that I could see the bearing cage had gotten dislodged and wedged in-between the worm gear and the bottom of the casing.  

 

You can see below the indentation of the worm gear assembly pushed the cap out.  

 

[mklotz70]

On 12/28/2020 at 4:40 PM, d.p said:

 

Not sure because the top half of the top bearing is still in the base of the column.  Not sure how to pop that one out?  And one would think they would be identical but who the hell knows with these trucks.  

If there's a lip of it, a really long rod?  Otherwise, maybe heat the large flange and then quench the race with a can of dust off held upside down.  

[mklotz70]

It's interesting that it did that.  I'd have to pop the top off on my frame jig and see what it does........but it's outside in the cold and rain.  Maybe if I think about it when it's fairly nice out.  

[d.p]

16 minutes ago, mklotz70 said:

If there's a lip of it, a really long rod?  Otherwise, maybe heat the large flange and then quench the race with a can of dust off held upside down.  

 

I am just going to leave the races alone and simply replace the bearing cages as you suggested.   I popped the bottom one out to allow me to get a part number which then allowed me to order replacements.  I reinstalled it shortly thereafter. 

 

Would love it if at some point you got around to checking but I will most likely find out what the deal is in the next couple days.   I would think there would be a mechanism to ONLY allow x and y amount of travel but as you see (and @datzenmike) it can travel far enough to push that cap out.    

[mklotz70]

But....can it travel far enough to push the cap out with the bearing in properly.  I don't think so.  I wonder if the bearing is completely out of the way if it could travel far enough to push the cap.  Maybe the shaft will travel and stop with an 1/8" of space left, but if the bearing is a 1/4" thick, then that extra 1/8" was enough to pop the cap.  With the bearing in the wrong position, if you tightened the 3 bolts that hold the tube to the box, that is probably what generated the force to pop the cap...but it didn't fall out......??  Then when you turned the wheel, that moved things enough to pop the cap the rest of the way??  There's a lot of times I run the video camera when I'm doing new stuff......for just this reason.  If it screws up, I can go back and review the vid to see what actually happened. lol  If all goes well, I can delete the footage rather than spend the time editing it.

[d.p]

9 minutes ago, mklotz70 said:

But....can it travel far enough to push the cap out with the bearing in properly.  I don't think so.  I wonder if the bearing is completely out of the way if it could travel far enough to push the cap.  Maybe the shaft will travel and stop with an 1/8" of space left, but if the bearing is a 1/4" thick, then that extra 1/8" was enough to pop the cap.  With the bearing in the wrong position, if you tightened the 3 bolts that hold the tube to the box, that is probably what generated the force to pop the cap...but it didn't fall out......??  Then when you turned the wheel, that moved things enough to pop the cap the rest of the way??  There's a lot of times I run the video camera when I'm doing new stuff......for just this reason.  If it screws up, I can go back and review the vid to see what actually happened. lol  If all goes well, I can delete the footage rather than spend the time editing it.

 

I think what happened was I first thought the column out through the cab so I took out the 3 bolts holding the column to the steering box and tried to pull it out.  I think at that point it dislodged the bottom bearing and when I pushed it back in it then sandwiched the bearing cage between the end of the worm gear and the gear box.  So maybe at that point it had enough movement to push the cap out?

 

 

[mainer311]

49 minutes ago, d.p said:

 

I think what happened was I first thought the column out through the cab so I took out the 3 bolts holding the column to the steering box and tried to pull it out.  I think at that point it dislodged the bottom bearing and when I pushed it back in it then sandwiched the bearing cage between the end of the worm gear and the gear box.  So maybe at that point it had enough movement to push the cap out?

 

 

Yes.

 

[/saga]

[datzenmike]

Was the sector shaft still in the box?  I think you can 'unscrew' the worn gear out of the box with the sector shaft in place BUT when putting back in the work must engage the sector shaft teeth properly or the worm will continue in too deep and pop the plug out the end. This is what I did on my 620. I corrected the mistake, hammered the plug back in and it was fine.

[d.p]

Who the fuck knows at this point because this is confusing as all hell to me and the more I fuck with it the more confused I get.   

 

This is how I reinstalled the worm gear in line with the sector shaft teeth which I gleaned off Mike's videos: 

 

 

So if I install a bearing in the bottom (nothing on top) and crank the worm gear/sector shaft all the way to the left (which pushes the worm gear down) the sector shaft gear will hit the boss and stop moving.  But I can still turn the sector shaft to the left the worm gear then backs off/lifts up and pushes off the bottom of the gear box.  It doesn't do that if I turn it the right (worm gear goes up) and it reaches the top of motion and simply stops.  

 

Here is a video of it:  https://drive.google.com/file/d/1rXUKkMZVVkVkcT4tqaEb1w3oRJUXUlg8/view?usp=sharing Watch at the end where the box tilts to the right as I turn the shaft to the left.  

 

 

[d.p]

Here is another video from the front:  https://drive.google.com/file/d/1s6_C5FuzIuKMpE5waBRxXMVaHooWJqf3/view?usp=sharing

[mainer311]

You do realize that when the pitman arm reaches its stops, and the gear rack can’t move anymore, that a thrust load is applied to the worm if you keep turning it, right? That’s the reason that it has opposing angular contact bearings on it, so it can’t move.

 

When the bearing cage fell out, it likely got pinched between the cover and the end of the worm, so it moved until the pitman hit the stop, and then the thrust load on the worm popped the cover off. 
 

The worm was allowed to move into the space where the bearings/cage normally reside, and there’s probably minimal clearance in that cage to begin with.

Edited December 30, 2020 by mainer311

[d.p]

Just now, mainer311 said:

You do realize that when the pitman arm reaches  its stops, and the gear rack can’t move anymore, that a thrust load is applied to the worm if you keep turning it, right? That’s the reason that it has opposing angular contact bearings on it, so it can’t move.

 

When the bearing cage fell out, it likely got pinched between the cover and the end of the worm, so it moved until the pitman hit the stop, and then the thrust load on the worm popped the cover off. 

yes no I don’t know.   
 

and that is exactly what happened the cage was wedged in between the end of the sector shaft and the opening at the bottom of the gear box.  You can see where the end of the shaft contacted the bottom cover and pushed it out. 
 

so I guess what you’re saying is that with both bearings installed I should be ok.  

[mainer311]

37 minutes ago, datzenmike said:

BUT when putting back in the worm must engage the sector shaft teeth properly or the worm will continue in too deep and pop the plug out the end.

I highly doubt it. The worm can’t pass the bottom bearing if its installed properly. If the sector shaft and gear rack aren’t meshed properly, you basically just get steering more in one direction than the other.

[mainer311]

1 minute ago, d.p said:

so I guess what you’re saying is that with both bearings installed I should be ok.  

Yes.
 

Mike mentioned the shims under the rear cover. These are very carefully set so that the top and bottom bearings get preloaded without binding. Once the rear cover is bolted on, the worm is locked into position in the axial direction.
 

 

[d.p]

1 minute ago, mainer311 said:

Yes.
 

Mike mentioned the shims under the rear cover. These are very carefully set so that the top and bottom bearings get preloaded without binding. Once the rear cover is bolted on, the worm is locked into position in the axial direction.
 

 

Got it.  
 

There are 3 shims there.  Hoping the bearings and o’rings show up tomorrow and I can put it all back together and move on.  

[d.p]

No luck with 3/8 BSPT for the gear fill either.  No idea what it takes because it’s not NPT BSPT or MIP.  I ordered a 3/8-18 NPT tap and will just tap it and use the plastic plug I first got. 
 

 

[Tucson620]

I would really like a new steering box for my 521. This is quite the adventure.

 

You're giving up too easy. I think Whitworth is the next logical thread choice!

[d.p]

Lol man stick around as I am sure it will continue once I get this installed, my driveshaft installed and go to start this fucker for the first time.  There is a steering box + column on ebay for $400 from Greece.  And I think that is the only one I have seen in the 4 years of owning this truck.  

[mklotz70]

The first vid said access denied.  Second vid worked

 

[Charlie69]

8 hours ago, d.p said:

Lol man stick around as I am sure it will continue once I get this installed, my driveshaft installed and go to start this fucker for the first time.  There is a steering box + column on ebay for $400 from Greece.  And I think that is the only one I have seen in the 4 years of owning this truck.  

Right or left hand drive?

[d.p]

LHD so it would work for our trucks. 
 

Got the bearings today from France.  Took about a week so not too bad.  Going to try and get this box and column back together and reinstalled.  
 

Still waiting on my driveshaft as well but hope to have it sometime this week. 

 

 

 

 

[d.p]

Got it all put back together and saw that the plug in the bottom of the box was leaking so I popped it out to reseal it and now it’s deformed and refuses to go back.
 

I had thought I bought new ones from Nissan but you can see (left side) they are nowhere near big enough.   The 40mm engine freeze plugs are way too big so now I don’t know what to do.  maybe find someone to weld it in? Seems like the dumbest idea to have a removable plug at the bottom. What purposes it even serve?