DC3

My '73 with tilt/tele doesn't cancel turn signals well. It takes a very sharp left turn to cancel the signal. A normal right turn will cancel okay but a mid to sweeping right turn requires a bit of oversteer at the end to get it to cancel.

I had this problem once with a '68 Chevy Pickup and it turned out to be the turn signal cancel cam was worn.

Does that sound like what I am dealing with here?

Is this cam a PITA to change out or is it a fairly straight forward process?

Could it be out of adjustment rather than worn?

Could it be the turn signal switch itself rather than the cam?

The steering column and everything else connected to it seems to work fine. Is there anything else that I should replace at the same time if I swap the cam?

Thanks for the help.

DC

'75

Your cancelling cam is probably not the issue. If you pull the horn button and contacts, then pull the retaining nut for the steering wheel hub. You should see hash marks on the end of the shaft and also the hub. They are probably not lined up. I'm guessing your steering wheel is straight when you are going down the road straight. The way to center it is to first pull the hub and get it on with the marks lined up. Then adjust the tie rods to make the wheel centered again. This will align the cancelling cam so that the same distance turned either left or right will result in the signals being clicked off.

DC3

Yes, my steering wheel is straight. I'll check the hash marks and see how they line up. I was thinking cam because even though it will cancel right turns, it doesn't cancel some of the medium to wider right turns that my '05 Suburban will. Didn't know what was normal for my Vette. How well will it cancel when everything is lined up properly?

If I have to re-center the hub and adjust the tie rods, I assume I make the adjustments with the wheels hanging in the air?

DC

Jim Shea

The following paper describes some easy checks for your steering gear, flexible coupling, T&T steering column, and steering wheel to insure that they are all assembled to OEM specs. Most of the descriptions are visual. You never know what Bubba could have been doing to your car over the last 30+ years.

http://jimshea.corvettefaq.com/wp-co...Rev18MY061.doc

BTW, the turn signal switch has two circular springs that are used to cancel the switch out of right and left turns. I have seen the springs become dislodged from the switch and not cancel at all. I haven't seen them worn. Possibly your canceling cam could be worn but it does sound to me that your column isn't centered.
Jim Shea

DC3

Thanks Jim. The paper should come in handy and I will put it to good use to help determine the problem. I was getting ready to order some parts and thought of ordering a new cam at the same time but will put that off until I can confirm what is happening. I believe the previous owner rebuilt the steering column and maybe he just didn't get things centered back up correctly.

DC

DC3

It looks like Bubba is alive and well. As best I can tell without lifting the car, the pitman arm and steering wheel are dead straight where they are supposed to be. However, while the flat on the input shaft and the stop pin are lined up together, they are over 90 degrees off from pointing straight up. I'll still need to verify the hashmarks on the hub and upper shaft as described by Aktbird but I don't see how they could be lined up after reading the paper you provided.

It looks like once I get the hash marks lined up and input shaft in the correct orientation that I'll have to pull and re-align the pitman arm to get everything square to the world. Does that sound about right?

DC

TimAT

Unless my memory is totally AWOL (may be??) the pitman arm and the steering box have a master spline so you can't put the arm on incorrectly without a LARGE effort. More likely everything has been adjusted to compensate for something being worn.

I'm with Jim on the cancel cam- I've seen those springs broken too.

BenUK

I think the pitman arm on my '76 can be placed at any of the four 90 degree positions. I've just reinstalled mine after completing my body-off chassis resto.

Jim Shea

You cannot install the pitman arm 90 degrees off. The arm will be pointing directly at your tires and obviously not correct.

When the gear is not on center (flat not at 12 o'clock with wheels straight ahead) you will have looseness as you drive straight ahead.

You may be able to correct the problem with the tie rod adjusters but you will also need to correct the steering column/steering wheel.

Jim

BenUK

Doh!

DC3

Yep. Verified everything today.

Turning the wheels so that the flat spot on the gear shaft is pointing straight up (12 o'clock) results in the following:

1. Stop pin is correct. Pitman arm points straight ahead. Lower column clamp bolt is correct. (looks just like the photo in the centering paper)

2. Tires point slightly to the left

3. Steering wheel is left by 120 degrees

4. Chisel mark on upper end of shaft is at 6 o'clock.

5. Mark on hub is about 4 o'clock.

6. The larger (3/8) bolt on the flexible coupling is at 9 o'clock and the smaller bolt is at 3 o'clock.

I get a little more than 1 & 3/4 turns of the steering wheel to the left and a little less than 1 & 1/2 turns to the right.


If I understand the paper and the advice here, all this means that I must do the following:

a. Adjust the tie rod ends to get the flat spot, stop pin and lower column back to 12 o'clock.

b. Pull the hub and line it up with the upper shaft mark.

c. Re-install the steering wheel in the correct orientation.

d. Fix the problem with the upper and lower shaft being off by 180 degrees. This assumes I am understanding correctly that by having the upper shaft chisel mark at 6 o'clock when the gear shaft flat spot etc are at 12 o'clock means the upper and lower shafts are off by 180 degrees? If that is the case, I may cheat and do the "easy" fix mentioned in the paper and wait until I have a reason to go into the steering column to put it back correct.

Anything I'm missing?

DC

'75

Sounds like you've worked through it and didn't miss anything.

Jim Shea

I think that you have analyzed your problem correctly. You don't require a new cancelling cam! Swapping the two flex coupling bolts should allow you to rotate the lower column shaft 180 degrees and get the upper shaft back to the correct orientation.
Jim

DC3

Is is best to adjust the tie rods with the weight off of the front wheels or does it make any difference?

Thanks for all the help.

DC

DC3

Got it done. Everything works much better. Steering feel is better while driving. I did have to pull the rag joint and flip the column 180 degrees.

Only snag I ran into was with everything centered perfectly down below, the steering wheel including the mark on the upper shaft and the mark on the hub were off to the left about 6 degrees. At this point the left turn cancel was slightly better than the right turn cancel. Pulled the hub again and shifted it by one spline. Steering wheel was now straight on and turn signals both cancel about the same. Not as good as I would like but at least they are equal. If I make a turn from a near lane into the closest lane, the canceling mechanism works fine. If I turn out of a near lane into a far lane I have to give it a bit of over-steer to get it to cancel. Don't know if that is normal but for right now it is something I can live with.

One of these days, I'll mate the upper and lower parts of the column correctly and correct anything else I find amiss but for right now its too good to mess with.

Thanks for all the help.

DC

Jim Shea

Glad you got it fixed to your satisfaction. I don't think that your turn signals were designed to cancel when you make a lane change. It sounds as if everything is fine.

Jim

DC3

I didn't mean during lane changes. What I meant was that it cancels fine in either direction for sharp turns but if the turn is wider it doesn't. Imagine an intersection of two multiple lane roads where I have a choice of two or more lanes to turn into. Turning into the nearest lane (ie the sharpest turn) cancels fine. Turning into the lane furthest from my position doesn't always cancel unless I give it a bit of over-steer (to force a sharper turn).

DC