TR2/3/3A Signal switch on TR3 Horn Control Head not canceling

The Horn Control Head for my tr3 isn't canceling when installed, BUT when removed from steering column it "appears" to be fully functional in that the indicator lever springs back when I push in the corresponding exposed "peg". It also returns when the alloy collar that fits around the inner neck of the control head is turned approx. 320*. .

It wasn't working when I got the car and was obviously disassembled at some point. I have had it fully apart (quite a "Jack In The Box) and believe it is complete and correctly assembled with one possible exception: the exposed rounded corners on the spring-loaded pegs are facing away from each other. Is this correct? The pictures I have seen on-line do not show the orientation of the pegs to each other.

It has been suggested the steering column / stator tube may not be aligned properly in the car therefore not engaging with the control head. Your thoughts?

Details that might help in diagnosing the problem include:

-I have an adjustable steering column
-Signals and horn work fine otherwise
-The bayonet fixture slots into the stator tube fine preventing the smaller inner disk of the fixture from turning while the outer larger disc turns freely.
-When attaching control head to the bayonet the indicator lever is pointing up, the prong on the outer larger disc is pointing out at the bottom of the large disc disc, and the slot of the alloy collar is positioned over said prong.
-Horn assembly turns with steering wheel.
-Assembly is secured with setscrews on hub of steering wheel
-Even when turning steering wheel to full lock signals do not cancel

If you have been able to follow along up to this point let me know what you think may be the problem.

First question, when you turn the wheel, does the turn mechinism turn with the wheel or remain relatively stationary?

As mentioned it turns with steering wheel and is locked inplace on hub with three set screws. On looking at additional pictures online it would appear that the rounded corners of the pegs should be facing each other.

Assume you have seen this article on dis-assembly. That is what I used as a reference when I rebuilt mine. https://www.tr-register.com.au/Files/technical/ControlHead.zip

Believe this is correct orientation of the pegs.



Cheers, Mike

I think

Scotsman said:

As mentioned it turns with steering wheel and is locked inplace on hub with three set screws. On looking at additional pictures online it would appear that the rounded corners of the pegs should be facing each other.

Click to expand...

The turn knob should stay stationary when the wheel is turned...i.e, it should not turn with the wheel. If it does, your stator tube may need to be locked at the bottom of the steering gear, under the front apron. It sounds like the stator tube itself is intact from your description. Once you get the turn signal knob stationary, we can figure out the cancel arm situation...

Scotsman said:

-Horn assembly turns with steering wheel.

Click to expand...

That's the problem. The entire control head should stay fixed in place and not turn with the wheel.

Either the stator tube is turning in the gland at the front of the steering box; or not engaging with the control head somehow. They commonly break at the bottom of the slot.

mgedit, I get a 504 error when I try to link to the url you posted above. Is the url correct? Thanks!
Regards,
Bob

The link works for me.

OK, it looks like I have at least two issues going on, the orientation of the pegs, and the moving control head.

Control head first.
-Can I tighten up stator tube without taking anything apart, and how do I do it?
-Is there be any reason for the previous owner to keep the stator tube loose (for example binding in steering column when tightened up)
-Should I be doing anything else such as lubing etc.?

The pegs
If above picture is accurate I'm going to have to take the little 'b----r' apart again. While I'm at it should any of the parts be greased?

Tip, if you are going to try this yourself do it with the control head inside a clear plastic bag. There are a multitude of small parts held in place with springs. I wasn't joking when I said "Jack In The Box"



Thanks john and randall for your input.

Richard

PS I also cannot get the above link to work

When I had a problem with the control head turning, it was due to the stator tube being broken at the control head.

Good luck,

Just clicked on the link in my original post and it worked OK for me. It is a zip file so maybe some security setting is blocking it? Cheers, Mike

Funny -- I've owned three different TR3s over the years and none of them had turn signals that self-cancelled. I just went under the assumption that there wasn't a cancel cam in there.

There is a nut and compression fitting on the front of the steering box, that locks the stator tube in place. You can look at the protruding end of the tube to see if it is turning with the wheel. If not, then tightening the nut will not help (and very likely will break something).

Since folks seem to be having trouble with the link, I took the liberty of converting the file & copying it here:
https://docs.google.com/file/d/0B2H2NJt34OffMUhOX1ZiVWdTbmM/edit?usp=sharing

I used "dry moly" to lube my control head last time around. I've used lithium grease very sparingly in the past, but it seems to accumulate dirt and get sticky over time.

There are some photos at https://s258.photobucket.com/user/TR3driver/library/Control Head that might help as well. Unfortunately, I laid the pegs in backwards for the photo-op, and haven't taken time to update those yet. (Nor to write the detailed article I planned at the time.)

Personally, I've never felt the need to use a plastic bag; although I do work over a bath towel. As long as you keep the main lever engaged in the rear housing, nothing goes flying around.

Scotsman said:

Control head first.
-Can I tighten up stator tube without taking anything apart, and how do I do it?
-Is there be any reason for the previous owner to keep the stator tube loose (for example binding in steering column when tightened up)
-Should I be doing anything else such as lubing etc.?

Click to expand...

Randall explains tightening the stator well. I can think of no reason it would be loose on purpose. The only binding possible is in the control head itself. So, if the horn button spins freely in relation to the lock plate behind it, you are good. If it binds, you almost certainly have a broken stator tube already. Unfortunately, it is very common.

From your posts, it sounds like you are working on the head with all the wiring still in the column. That is the hard way to do it. You may have to pull the wires through to work on it at the bench. Working at the column, I don't really see how the pegs could have gotten reversed...but I guess any thing is possible.

I have an adjustable steering unit, and this may require a slightly different approach. Description from Bentleys "The control head mounted in the steer & wheel centre is similar to the normal equipment with the exception of the stator tube. This consists of a short tube with indents at its lower end to form a key, and a longer tube with a slot at its upper end. The two tubes telescope together, the indents engage-ing with the slot provided.

The short tube looks to be intact, and it appears to slide and lock into the longer tube.

Does anyone have an adjustable steering unit and have input as to how to troubleshoot this.

Thanks,

Richard

The adjustable version works exactly the same as the fixed. The upper tube is longer and the slot in the lower tube is longer, but that's about the only difference. The lower tube might be a couple of inches shorter, but ISTR it is the same length (just has a much longer slot).

Did you check whether the protruding end of the stator tube is turning with the wheel? If you don't have a helper handy, just make a mark on the tube, then turn the wheel and check to see if the mark moved. If it didn't move, then IMO it is time to pull the stator tube out of the column. You can leave the wires in the tube, but you'll need to disconnect them from the harness (up by the driver's side horn) and pull them out of the clip on the inner fender. The tube only comes out to the top, so you'll also need to undo the 3 grub screws in the steering wheel, and pull the control head out with the tube & wires.

Here's a shot showing the difference in the slot, from Mark Macy's site:

Based on the feedback I have identified two issues.

1 The pegs on the control head have been reinstalled facing the wrong direction
2 The stator tube is probably broken as on tightening the gland nut the head continues to turn with steering wheel.

Being that the signals work this is not a pressing issue so I am going to wait a while before taking everything apart, but will let you know the outcome when I do. Thanks everyone for your input

Don't forget though, that every time you turn the wheel, it is twisting the wires behind the control head. Eventually, it will tear up the wires and the turn signals will no longer work. If your luck is really bad, the horn wire will short to the tube and the horns sound continuously until either they overheat and blow the fuse, or you open the hood and pull the fuse.

Since folks seem to be having trouble with the link, I took the liberty of converting the file & copying it here:
https://docs.google.com/file/d/0B2H2NJt34OffMUhOX1ZiVWdTbmM/edit?usp=sharing

TR3 CONTROL HEAD ASSEMBLY. Thanks for posting this link, Randall. I wasn't able to access the earlier link either. I bought a used control head on ebay 10 years ago with an eye towards restoration. The unit looked good, and I was pleased until today when I took it apart, getting it ready for installation. The item had been taken apart by PO, and been severely molested with broken parts, missing parts, loose parts, and in general, not salvageable. Fortunately, I had bought a second spare that appears to be unmolested, and in original condition. It even has the original wires attached, and I believe I'll install it as is. Looking for completion date on the restoration in about a month. Ill post pictures when finished. First start-up after 30 years of slumber, and it purrs like a kitten (after a few tweaks). Thanks for all of your help and advice for getting to this point.

TR3driver said:

Don't forget though, that every time you turn the wheel, it is twisting the wires behind the control head. Eventually, it will tear up the wires and the turn signals will no longer work. If your luck is really bad, the horn wire will short to the tube and the horns sound continuously until either they overheat and blow the fuse, or you open the hood and pull the fuse.

Click to expand...

This happened to me. The wires were frayed and shorting out. Just finished installing a new stator tube (the original was broken at the notch and the control head turned with the wheel) and a new harness. The stator tube was unavailable in the US so I bought some tubing and my machinist buddy milled a new notch. Disassembly and reassembly of the control head was interesting and required patience. After switching the color coded wires around, I now have everything working. Signals and horn work, it self cancels and the control head no longer moves with the wheel although there is some play in it. It's a job that I wouldn't want to do very often.