TR2/3/3A Another Steering Box Question

[BobbyO]

I have read numerous past posts about steering box adjustments and the one Randall posted measuring end float using a dial indicator is excellent. My question is, is there any way to measure end float without totally dismantling the steering with the unit still in the car? For instance, is it somehow possible to make the measurement after loosening the horn/direction signal assembly to get to the top of the shaft. I would rather not remove the wiring running down the inner tube if at all possible. Trying to do something the easy way usually doesn't work but I can hope anyway.

 

[TR3driver]

Easier IMO to just remove the tube with the wiring still inside it. It slides out and back in a lot easier than trying to pull the wiring through the tube again.

 

[BobbyO]

Great idea Randall. Hadn't even thought of that. Would be so much easier. Will the nut on the end of the tube fit through the column or would it have to be removed?

 

[TR3driver]

You'll have to remove the nut and work off the gland underneath it to release the tube. If there is any oil in the box, it will start dripping out too.

 

[BobbyO]

Sorry Randall. When I said "nut" I meant the gland (olive). Anyway, I have now gotten myself totally confused. I have an extra half steering column so I went out, removed the lid, the shims from the end (three measuring 0.012 total, two 0.003 and one 0.006) and replaced the end piece. Now, exactly what are we measuring the end float of? It seems to me if you add shims it would increase the distance between any pieces in the steering box thereby increasing an end float. Where am I wrong? What is the float we are taking out by adding shims?

 

[BobbyO]

For what it's worth I missed two shims, an additional 0.006 and 0.011. They both were steel while the others appeared to be brass.

 

[CJD]

The plate which has the olive is shimmed to set the play in the worm gear roller bearings. Any play in the worm gear, so the steering shaft can move in and out is lost motion in the box, and results in play. Shim this plate to have 0 play to a very slight preload. You do not want enough preload to bind the rollers, or they will fail.

The plate on the top, having the adjuster and lock nut, does not get shimmed. You set the position of the steering peg in relation to the worm gear with this adjuster. You must have the gear in the center position to set this adjustment, as it is machined to be the tightest at center. It will have increasing play as you turn the gear off-center. Set the peg adjuster so there is only slight resistance at the center position. The resistence is so slight that the book recommends removing the steering linkage to set it properly.

Clear as mud?

 

[TR3driver]

It seems to me if you add shims it would increase the distance between any pieces in the steering box thereby increasing an end float. Where am I wrong? What is the float we are taking out by adding shims?

You're not wrong at all, that is exactly right. Add shims to increase float (or reduce preload). We're adjusting the end float of the worm between the two ball bearings.

In general, add a shim, measure the end float (how far the column moves in and out when you wiggle the drop arm back and forth), then remove shims equal to (or .001" larger) than what you measured. Don't forget to back off the screw on the top first, as it can cause a false reading.

FWIW, I've got an old book on Bishop steering that suggests removing shims until the shaft will "spin round when turned, but not too freely." But I still suggest using the dial indicator.

Also FWIW, Enco almost always has a dial indicator and magnetic base set on sale for under $25. Today it's only $19.95
https://www.use-enco.com/CGI/INSRIT...MKANO=402&PMKBNO=3680&PMPAGE=48&PARTPG=INLMPI

Or Harbor Freight sells for about the same price.

 

[BobbyO]

Great explanation John. After I removed the final two steel shims and put the end plate back I could see it was not flush against the end of the steering box. After awhile it dawned on me that the end plate was shimmed in order to allow for adjustment for "end float" caused by wear on the plate. By removing shims you could take out any float caused by that wear. With Randall's method of using a dial indicator and adding a shim you're introducing additional false float, measure the total with the dial indicator and remove the necessary shims. Great job guys. Now I need to work on the steering box in the car, not the one on the bench. Sadly the one in the car is not a split column.

 

[CJD]

Yep, good luck getting a dial indicator on the long shaft! Remember that the worm gear is held by ball bearings, so the play should not change unless the balls are damaged or incorrectly installed to begin with. The balls should not wear if they are in good shape.

Most play in the gear is from wear of the peg on the pitman arm that engages the worm inside the box. This would be taken up by the adjusting nut, but more than a little wear cannot be adjusted out. The peg is easy to replace ( or just remove and re install 90 degrees off), but the box will have to come out of the car to do it.

 

[sp53]

In case you did not know, the long shaft has to have the apron removed to get the shaft out and the pitman arm removed. The pitman arm itself is stuck very tight to the splines, so even if you get the nut off, the arm is the biggest challenge. I am curious what adjust concerns you most? If the box is steering difficultly, the problem is often the idler arm right across from the box. You can fix some leaks with the shaft in, but any major service needs to have the box out.
steve

 

[TR3driver]

Even the long column will come out without removing the drop arm (aka Pitman arm). You do have to remove the apron, though.

IMO the adjustments are NOT to take up wear, rather they are to compensate for manufacturing tolerances. The ball bearings won't wear at all (less than one shim thickness) until they start to fail and need to be replaced (which should be about forever). The peg and worm certainly wear, but they don't wear evenly. If you try to get a tight spot in the center with worn components, there will be places where it is too tight and the result will be damage to the peg & worm (from overloading, tight spot plus steering force).

Here's a shot of a dial indicator mounted on a long column.

 

[CJD]

In case you did not know, the long shaft has to have the apron removed to get the shaft out and the pitman arm removed. The pitman arm itself is stuck very tight to the splines, so even if you get the nut off, the arm is the biggest challenge. I am curious what adjust concerns you most? If the box is steering difficultly, the problem is often the idler arm right across from the box. You can fix some leaks with the shaft in, but any major service needs to have the box out.
steve

I always just take the body off first!

 

[BobbyO]

Now I'm into a whole new ball game. I understand I would have to remove the column in order to rotate the peg 90 degrees but that brings me to another question. What is the best way to remove the drop arm? I have two spare split column steering boxes with drop arms attached but no upper portions of the column. Consequently I installed the rigid column. There was no drop arm on that column so I attempted to remove one from the other columns. No luck. Was able to remove the nut but the drop arm wouldn't move. Even took one to a machine shop and they couldn't remove it either. Didn't have much confidence in that machine shop but gave up and purchase a drop arm on ebay. It's installed so now I'll have to remove it to rotate the peg.

 

[CJD]

A well equipped shop would have no problem removing the arm. I use a pitman shaft puller that I bought many years ago. It has a couple clamp arms that grab the steering arm and a center screw that pushes on the shaft. Takes less than a minute, and most of that is finding the tool in the box. Even at todays rates it shouldn't be that much...

Just googled "pitman shaft puller" and at least a dozen different designs popped up, starting at $19. Good investment for dealing with all your boxes!

 

[CJD]

Oh...realized I may have an upper column in storage...I'll look if you think it would help.

 

[TR3driver]

A purpose-made Pitman arm puller is the only way to go. The opening was a little small on the one I got (they do come in different sizes), so I machined it to fit the TR. I'm pretty sure this is the one I started with
https://www.harborfreight.com/tie-rod-and-pitman-arm-puller-62708.html
but I opened the jaws up to 1.5" (from 1.3125") to fit the TR arm. (I used the mill, but you could do it with a file and lots of elbow grease. Be sure to cut the same amount from each arm, so the opening stays centered under the forcing screw.)

I have done it using a common 2-arm puller, but I had to make up brackets to lock the puller arms onto the tabs on the Pitman arm (otherwise they kept slipping off) and it was close to breaking by the time the arm came loose. The purpose-made tool works much better.

 

[sp53]

John I think you were lucky getting the arm off so easy. The last one I did with a couple of machine shop buddies at their shop had to heated and they were about ready to give up right before it popped.

 

[sp53]

When you remove the shaft and arm, there will also be a brass bushing in the case of the steering box that probably/should needs replacing to get your box tight again.

 

[TR3driver]

When you remove the shaft and arm, there will also be a brass bushing in the case of the steering box that probably/should needs replacing to get your box tight again.

+1 Unless it has been replaced recently, I would always change the bushing and seal.

IMO, wear in that bushing is one of the main reasons for hard steering. It lets the rocker arm tilt, which causes the peg to bind in the worm (only when steering force is applied). A friend of mine even added a second bushing in the web above the first one, which sounds like a good modification (I plan to try it next time I have the box apart).

Wear in the bushing also causes them to leak.

IIRC the book says the bushing should be reamed after installation, but I've not found it to be necessary. YMMV