TR2/3/3A TR3A Steering Shaft stator tube???

[CraigLandrum]

After disassembling, cleaning, and buzzing out the turn signal and horn contacts in our steering control head for our barn-find TR3A, we puzzled over how the control head mounted onto the shaft so that the control head would stay static while the wheel turns (to allow the turn signal to reset after the turn). We know about and have the three set screws that attach the head to the wheel. After perusing the TR3 maintenance manual we realized that we we are apparently missing the stator tube, which runs down the middle of the shaft and emerges at the bottom of the steering control box at the front of the car, held in place with a compressor nut (we have the brass bushing and compressor nut). The small shaft that is part of the control head itself just fit into the top of the steering column shaft, so we suspect that the missing stator tube will need to be a tight press fit inside the control head shaft, but large enough to allow the wires to go through, and long enough to extend all the way through the steering control box in a single piece, in order to hold the turn signal part of the control head in the 12 o'clock position.

Couldn't find any specs, but it appears that this tube would be about 3/8 inch outside diameter with a thin wall, and would need to extend from the steering wheel all the way down through the control box.

This part is marked N/A in every catalog we could find. Does anyone have the exact specs for this tube (diameter, length), assuming it is for a non-adjustable standard TR3A steering column? I suspect I might be able to pick this up at a hardware store somewhere. Any tips appreciated.

By the way, disassembling and cleaning a TR3 control head is an exercise in frustration, and it involved simultaneously positioning the turn signal arm, a spring-held contact plate that is a slip fit on the arm, a spring loaded brass slotted piston with a teensy roller wheel, and a curved 180 degree rod holding two *more* compressed springs that help return the signal arm to its proper position. Oh, yeah, almost forgot the two spring-loaded cams that must also be correctly positioned in slots as you are trying to hold the other four springs in position - all while trying to insert the small brass bolt, lock washer, and brass nut that holds it all together. We finally got it assembled correctly after our fourth attempt, and the the turn signals buzzed out on the meter and the signal arm correctly resets to the center position after a simulated turn. Then we had to figure out the non-intuitive horn wiring which is held on with another two brass screws, etc, etc. If anyone ever needs to take one of these things apart to fix or repair, ask us first - we can offer some good advice gained through painful experience

 

[MGTF1250Dave]

Aloha Craig,

The stator tube is a 3/8" OD steel tube with a 5/16" ID that is 61 1/2" long. The control head end may have a 1/16" wide slot of 1 3/4" length running longitudenally to accomodate the raised portions of the control head tube to keep it from turning in the stator tube. This slot is present in an adjustable steering wheel assembly and may not occur with a non adjustable steering wheel. There are also three anti ratle spring devices mounted externally on the stator tube to keep it centered in the steering column. The originals are metal and are similar in appearance to paper chinese lanterns. I don't know they are available now but there may be some plastic alternatives offered.

 

[TR3driver]

Mark Macy ( Macys Garage ) is the current supplier for stator tubes.

I don't have the dimensions handy, but the non-adjustable tube is different than the adjustable version. Tube itself is longer, slot in the end is shorter. However, my recollection is that the non-adjustable slot is at least 1-3/4" and the adjustable one is rather longer than that. It has to be, as that joint is what moves when the wheel is adjusted.

Sorry, I accidentally left my non-adjustable tube in the car when it went to the body shop, so I can't measure it at the moment.

The short tube that protrudes from the control head fits over the stator tube, and has a row of dimples that engage with the slot.

 

[TR3driver]

BTW, Craig, there's been a lot of demand for a control head assembly article. Here's your chance to be famous

 

[martx-5]

The stator tube has three (what Macy's Garage calls) anti-rattle spacers. In reality, they are bearings that keep the tube centered and also allow free turning of the steering shaft around the tube while the tube remains stationary. Those bearings are free to rotate within a cut down section of the tube.

And yes, I would be interested in a "how to" on the control head.

 

[Geo Hahn]

Since I didn't see it mentioned, here's a link to Mark's site where replacement stator tubes are available.

https://www.macysgarage.com/myweb6/Parts/other_tr2_3_parts.htm#TR2/3 Stator Tube

Yes, you need the anti-rattle thingies on there... I prefer their common name which is so descriptive: Chinese Lanterns!

 

[Don Elliott]

Clive Elsdon in England did a great job how to dismantle the TR3 control head. Click below on this Australian TR site and scroll down to "DETAIL - Pre-2006" near the bottom of this list and you'll find it.

https://www.tr-register.com.au/Files/technical.htm

Another good tech site is : -

https://www.britishcarlinks.com/technical_articles_page.htm

These make for good reading during a cold winter.

 

[CraigLandrum]

Thanks for the tips guys - I've ordered a stator tube from Mark.

Clive Elsdon's guide to disassembling the control head is a good one. I might add a couple of tips here. It will help to download Clive's excellent document which includes a nice set of pictures:

- You can easily remove the face of the horn by removing the three silver screws to be found on the underside. If you have a stuck horn or a horn that operates intermittently, removing this face will likely show you the problem. Mine was that the round brass contact (looks like a large brass washer) had come unglued from the rear of the horn button and had to be reglued. I roughened the area where it would be glued plus the back of the contact and then used 5 minute epoxy to glue it back in place.

- The large central horn button itself had a tendency to fit too tightly into its hole in the face plate, and the central spring was not strong enough to overcome this, causing the horn to stick in the on position. I used a dremel with a small sanding drum attachment and carefully went around the recessed rim of the button where it met the side of the central hole. I took very little material off - essentially just roughing it up - but it was enough to eliminate the sticking button problem.

- The divided brass spring contacts under the horn button are - of course - the contacts that cause the horn to sound when connected via the round brass "washer" on the underside of the horn button. One of these two contacts is connected via a long brass bolt and nut arrangement to the thick brown and blue wire that comes into the bottom of the control head. The other contact is connected via a long brass bolt and nut to a tab on a large round brass shim that can be accessed by removing the recessed screws on the underside of the control head. This brass shim provides connection to ground. Removing these three screws also gives you access to the other wire connection points for inspection and repair.

- The incoming green and ? wire is the hot wire for the turn signals and connects to the central of
the five nuts. The other two are the blue and white wire which is the RH turn signal, and the other blue and ? wire is the LH turn signal.

- It is not necessary to unbolt the three turn signal wires to take apart the turn signal mechanism. You should have a good solid hold on the top and bottom of the mechanism before removing the final brass bolt which is revealed after removal of the horn contacts referenced above. Before removing this screw however, note carefully the position of the two spring-loaded metal lever return activators that appear on the opposite side of the control head from the turn signal lever. Note especially which way these activators curve on their ends as it is vital to put them back in place correctly later. A good idea might be to mark one of them as left or right with a marker.

- Once the clamping brass bolt is removed, carefully and slowly release the two halves of the control head. Springs and rods and small parts will appear.

Assembly notes:

- The smallest spring goes under the "quarter moon" brass connector which is a loose slip fit to the central swing arm, and provides the contact between the central hot turn signal wire and the left or right hand turn signal wire.

- The second largest spring goes in a hole in a square, brass, end-grooved piston which then fits into a square hole in the end of the swing arm. A very small silver wheel fits into the grooved end of this brass piston which presses on the left or right spring-loaded activation lever, causing it to stick out of the underside of the control head. When the turn signal lever is in the central position, this small wheel rests on a "V" shaped plastic area integral to the base of the control head. During reassembly, you will want to position the swing arm so that this small wheel make contact with this "V".

- The activation levers are spring-loaded so that they bend in the middle (as the steering wheel is turned and the return activation plate rubs across them). They are curved on their exterior ends to allow this plate to pass on one direction, but catch in the other direction, pushing upwards on the tiny wheel and thus releasing the swing arm to return to its central location.

- What causes the swing arm to return to its central location are two long springs threaded onto a heavy half-circle of steel wire. This wire fits into a slot in the swing arm. There are two small washers that also thread onto this wire and are positioned against the side of the swing arm. The springs press against these washers. It is just possible to position the springs, washers, wire guide, and swing arm when assembling the two halves of the control head, while also holding the "quarter moon" turn signal contact and spring in place, while also compressing the square brass piston, spring, and small wire wheel into the "V" shaped central position holding spot. All this must be done while ensuring that the two spring-loaded activation levers are positioned correctly in their guide slots (note that these levers have a guide cam on one side which matches a groove in the control head plastic).

- It is useful to lightly oil the moving parts of the swing arm mechanism before reassembly - I found that this cured a problem of the swing arm sticking partly in the left position on my control head. I oiled the small wheel, the square brass piston, and the guide slots that the activation lever cams ride in. I added a thin film of grease to the ends of these levers where they meet the tiny spring-loaded wheel.

- The trickiest part the assembly of the swing arm is described above. A second pair of hands is valuable - one to position and hold everything while the other guides springs and inserts the brass clamping bolt and nut which hold it all together. Once this bolt is inserted and snugged down, the remaining horn contacts with their two brass bolts and nuts can be easily reassembled. Note that the incoming large brown and blue horn wire is NOT bolted to the large brass shim ring on the underside of the control head - it is simply attached with a nut to one of the horn contacts - the other horn contact is what is attached to the tab on the large brass shim ring, which eventually goes to ground.

- The control head face can now be attached with the three large screws - be sure to insert the plastic horn spring retaining button into the center of the horn contact board! This holds the small end of the horn button spring - the large end of the spring goes in a recess in the horn button itself.

...and that's about all I can think of for now. Contact me if anything isn't clear. If someone thinks it might be of value, I can try and find the time to document all this with pics, but Clive's pics should get you through most problems.

 

[PeterK]

Craig,

The stator tube is removed out the cockpit after the nut and compression fitting is off at the steering box. It's a fairly easy job but the original anti-rattle baskets aren't used with the s.s. tube that Mark sells. His uses plastic replacement anti-rattle pieces.

I removed the wiring harness from the front left side just at the driver horn area and inserted it into the stator tube before reinstalling the stator. Easier to do tis on the bench IMO. I pulled the control head harness just shy of the end of the tube so that it was easy to grab a wire with a hemostat/small needle-nose plier after the tube was in.

Nice control head write-up!

-PK

 

[Russ Austin]

This needs to be added to the BCF WIKI! Craig great job of added to Clive's document.

 

[Twosheds]

- The large central horn button itself had a tendency to fit too tightly into its hole in the face plate, and the central spring was not strong enough to overcome this, causing the horn to stick in the on position. I used a dremel with a small sanding drum attachment and carefully went around the recessed rim of the button where it met the side of the central hole. I took very little material off - essentially just roughing it up - but it was enough to eliminate the sticking button problem.

Craig, is this the control head Rob bought from me? That one had a sticky horn button.

Or did you find another one in a box of parts?

 

[rlandrum]

Craig, is this the control head Rob bought from me? That one had a sticky horn button.

Or did you find another one in a box of parts?

It's the original that came with the car (we'll assume). We used yours mostly as a reference guide.

Both have "sticky" horn buttons. There's a small ring of chrome around the button, and I think the metal eventually expands (from hot and cold heat cycles) to a more relaxed state that causes mild interference with the button. That's the theory anyway.

 

[DNK]

Why does the turn signal have to be so complicated in the side screen cars?

 

[TR3driver]

Why does the turn signal have to be so complicated in the side screen cars?

Just part of the charm of the car, IMO. Having that central section that does not turn with the rest of the wheel is cool; and everything else is just how to accomplish that.

Given that the original control head from TS39781LO has 50 years and nearly 300,000 miles on it; and I'm planning to move it to TS13571L; I'd say it was actually a pretty good design.

By contrast, the turn signal switch on my 13yo American LBC support vehicle crapped out a few days ago; and it's replacement cost about $150 and had to be ordered. Just a WAG, but I'll guess it's seriously complicated inside as well. And it doesn't include the horn button (which already failed and was nearly $500 from a dealer).

 

[newmexTR3]

Hey Craig,

I had similar problem installing mine a few months ago and there are some more good tips in this thread: Turn Signal Return Mechanism thread

Is there a wiki entry for this yet? I can put all this info together if not.

Also, as recommended by Art and others, I purchased a replacement stator tube wiring harness from British Wiring. Theirs is wrapped much tighter than the one that comes on the new control heads from TRF. I had MAJOR problems getting the TRF harness through Mark's replacement tube (* it should be stated that others did not have the same problem with the same equipment, but just in case you do...).

Cheers,
Gavin

 

[Don Elliott]

Craig - I never had a sticking horn button till I took off the chrome ring to have it re-chromed. I had to straighten out the retaining tabs on the back to get it off. When it came back, the thickness of the chrome took away some of the radial clearance. But more than that, when I bent the tabs back to retain the ring to the black bakelite outer ring, the extra chrome on the tabs made the tabs stiffer resulting in the tabs bending in a different way and this caused the "wall" of the ring to have flat spots (out of round) where the tabs were. I would honk the horn and it would keep on honking.

So I took it apart and with a small square file, I filed more clearance on the step that we see all around the horn button. This gave me the clearance I needed.

 

[Russ Austin]

Gavin; This thread with it's info needs to be in WIKI entry and it sounds like you be da man to put it togather!

 

[CraigLandrum]

The control head I just took apart, fixed, and reassembled appears to be the original with the original wiring. The wiring appears to be in good shape. We have a brand new complete wiring harness from Moss - will check to see if that includes the control head wires and if they look like they are wrapped tighter, may try and use the new ones.

I used to yank RS-232 serial cables thru conduit using a fish tape, so I imagine that pulling the control head wires thru 5 or 6 feet of stainless tubing should be doable. I'll keep the tips you guys offered in mind when we get to that point

Mark told me about the thick walled heat shrink tubing he uses instead of the "lantern" anti-rattle springs and I think its a good idea - probably less chance of things breaking and working down the tube to the top of the steering box.

Not sure why the two control heads we have both had sticky horn buttons. After disassembly, I first tried using a large smooth steel rod and ran it around the inside of the horn button hole to try and urge the chrome bezel that fits around the hole to expand a bit and let the horn button work smoother, but that didn't work and I finally resorted to the light touch with the dremel as previously described and that worked fine. In hindsight, simply applying a drop or two of oil around the rim of the horn button might also allow the button to slip easier past the chrome bezel, but I didn't try it.

I suspect that the reason the horn sticks is a gradual weakening of the horn spring/metal fatigue over 50 years time, although mine looked fine with no rust or corrosion. In any case, the dremel sanding technique worked fine and if done carefully cannot be seen from the front after assembly.

Will append a note here after the stator tube assembly and let you know how it went.

 

[Twosheds]

Not sure why the two control heads we have both had sticky horn buttons. After disassembly, I first tried using a large smooth steel rod and ran it around the inside of the horn button hole to try and urge the chrome bezel that fits around the hole to expand a bit and let the horn button work smoother, but that didn't work and I finally resorted to the light touch with the dremel as previously described and that worked fine. In hindsight, simply applying a drop or two of oil around the rim of the horn button might also allow the button to slip easier past the chrome bezel, but I didn't try it.

Didn't someone post in another thread that the bakelite button absorbs moisture and expands, causing the stickiness?

Or did I dream that?

 

[angelfj1]

Not sure why the two control heads we have both had sticky horn buttons. After disassembly, I first tried using a large smooth steel rod and ran it around the inside of the horn button hole to try and urge the chrome bezel that fits around the hole to expand a bit and let the horn button work smoother, but that didn't work and I finally resorted to the light touch with the dremel as previously described and that worked fine. In hindsight, simply applying a drop or two of oil around the rim of the horn button might also allow the button to slip easier past the chrome bezel, but I didn't try it.

Didn't someone post in another thread that the bakelite button absorbs moisture and expands, causing the stickiness?

Or did I dream that?

John: If memory serves, that was Don Elliott. But , memory is getting worse every year. :frown: