Overdrive switch upside down?

[Hande]

Can anyone help me. The Overdrive switch on my Tr4A appears to work upside down, operating upwards to engage when all other cars I have 'surveyed' it's (logically) down.

It does not appear possible for the switch itself to be inverted as it is dog-legged. The switch operates a relay, which in turn operates the overdrive solenoid. I have checked the wiring diagram and cannot see that inverting the switch wires can make any difference. Does anyone know what is needed to remedy.

Thanks, Hande

[Paul Harvey]

Hande,

 

Assuming you have a right hand drive 4A, you have an overdrive switch for a Left Hand Drive car which is designed to fit on the left of the steering column.

When you swing it through 180 degrees to fit on the right of the steering column it looks perfect, but works upside down.

I had one like this for years and just got used to it.

 

If it bothers you, you can unclip the plastic shroud and rotate the switch 180 degrees vertically and you will find the shroud fits back on fine.

The bend in the stalk will then be away from you, towards the dashboard, but will work the 'correct way' - i.e. down to engage overdrive.

You can carefully bend the stalk so it faces forward again (hold it with pliers BELOW the bend or you will damage the switch.)

If the switch is chrome plated you will find some of the chrome peels off at the bend and is very sharp.

You will also notice if you look really carefully that the little black tip is now facing the wrong way.

 

Alternatively, start the hunt for a correct, RHD, chrome overdrive switch.

Buy 2 if you find them as I have been looking for over 25 years.

If, on the other hand, you have a left hand drive car, please do nothing as you have the answer to all my prayers.

 

Cheers,

Edited May 6, 2014 by Paul Harvey

[AlanT]

http://www.ebay.co.uk/itm/COLUMN-OVERDRIVE-SWITCH-TR4A-WITH-CHROME-STALK-139793-/370628108578?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item564b282122

 

Chic Doig usually does good stuff.

[TRnorm]

How interesting, I'm just fitting up the various switches in my 4 rebuild and didn't give it a second thought to "Up would engage the OD"

It just seemed more logical to me. Up equates to moving up a gear, and vice versa.

 

As I say - interesting to know what is correct but I will stick to my own logic in this case.

 

Norman

[Paul Harvey]

Actually, I'm not sure my post above is entirely accurate.

The stalks are cranked 'up' and well as 'out.'

Rotating them horizontally and vertically makes the 3D visualisation difficult (I can imagine all the readers of my post closing their eyes and trying to figure it all out!)

 

You have the best idea - if it works, leave it.

Edited May 8, 2014 by Paul Harvey

[Rob Salisbury]

http://www.ebay.co.uk/itm/COLUMN-OVERDRIVE-SWITCH-TR4A-WITH-CHROME-STALK-139793-/370628108578?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item564b282122

 

Chic Doig usually does good stuff.

The one from Chic Doig in my car has been working perfectly for two years now, have found his stuff always good.

Cheers Rob

[RogerH]

Hi Hande,

are we correct in thinking that switch is on the righthand side of the steering column - that is where it should be.

 

You could move it to the lefthand side and then it would engage moving downwards.

 

If you find a correct righthand switch but it has a black stalk don;t panic - they are usually painted ot plastic sleeved over a chrome stalk.

 

Roger

[Paul Harvey]

Hande,

 

On the other hand if your stalk is chrome and you want it black you can send it to Roger.

He has all the equipment to deal with it.

Allow some time.

[Paul Harvey]

Rob,

 

Is the little black tip on the Chic Doig overdrive switch the correct way around?

Small point, but I found it wasn't and for some reason it bothered me.

Anoraksia, and its getting worse.

[RogerH]

Hi Paul,

a few moons ago I was contemplating making the end tip out of Ali and getting it black anodised.

After many years use the chrome stalk can go rather iffy. To be able to clean it and get it rechromed could be interesting - but probably not economic.

 

Roger

[AlanT]

Strip polish and replate will be about £10. Would work fine I think.

[Rookie]

It's something that confused me when I got my TR4A. The handbook (which seems to be the original UK handbook, despite having a LHD TR4 pictured on the cover) says "Move the lever up to engage overdrive and down to release it".

 

So I set the lever to the "down" position when I took my first trip in it. I was surprised by the big gap between first and second (which should have been a clue) and also surprised at how high-geared the car was. So I got it up to about 70mph and flipped the lever up to "engage overdrive" and it changed down.

 

I was wondering if my car had been rewired, but it looks like that's normal - it's just the handbook that's wrong.

[Rob Salisbury]

Paul, I'd never thought about it 'till now, just been out to the garage to have a look and indeed, it is the wrong way round!! I must admit that when I fitted the switch I modified (well bent it really) it so that it's directly under my out stretched middle finger when holding the wheel at 10 to 2, .... no messing around with overdrive logic boxes for me!! I like to be in control of the thing.

Cheers Rob

[stillp]

It's not upside-down - what you have there is an underdrive switch!

 

 

 

 

 

 

 

I'll get my coat...

[Hande]

Amazing and informative responses, thanks. My stalk is chrome but there is no indication that it has been bent. The black plastic sleeved end on the other hand is split and stays on only by reverse osmosis. I actually like the logic that up equates to going up a gear. I have got used to it and it's a quirk and probably not something that I am in a rush to rectify (except for the black sleeve). Note to self.........Remember when driving my best friends immaculate pride and joy, not to mess up and 'anti-switch' in 1st and 2nd !!!!!

[RAHTR4]

I have original TR4 and TR4A Owner Handbooks, each of these show the position of the overdrive switch as being fitted to the O/S of the steering column and the text states - to engage the overdrive, the lever should be moved upwards.

 

I also bought a new reproduction overdrive switch from Chic Doig and the quality is very good, on mine the black plastic tip is in the correct orientation.

This switch also engages the overdrive when moved upwards.

 

However, if required these switches can be modified to work in the opposite direction by changing the position of a single wire.

 

The switch has three contacts in a line, only two have wires connected.

 

For upward operation - the top contact is unused, the middle contact is wired and the bottom contact is also wired.

 

For downward operation the top contact is used, the middle contact is wired and the bottom contact is unused.

 

Regards, Richard

[mike3md]

I modified mine as Richard suggests to have a down/in up/out action. I suppose another way of doing it would by the addition of a relay, which is closed when the voltage is zero (ie the switch is in the down position).

 

Mike

[Paul Harvey]

I started out as a complete expert in these switches and now I have no idea, and nor does anyone else it seems.

The collective knowledge of the Forum does not even know which way Triumph intended the switches to work!

 

I do know how to convert one of these switches to a completely reliable momentary operation to suit the Revington Logic system....

[AlanT]

Its pretty common in electronic manufacture to find that when an item can be connected in two different ways and both lead to a "workable" outcome, the build standard wil drift back and forth at random.

 

This is what quality control is for. Stuff that won't work if mis-wired "polices itself".

 

It's a real problem when one connection works but creates an unseen hazard. I had to investigate a fire, caused by an electrical transformer. The fuse was wired in the neutral side and a few other things.

 

Quite often the error creeps into documents, manuals, test-methods etc

Then its really hard to get back on a "standard".

 

It would not surprise me if the swiches had not "arranged themselves" in a 50/50 split by now.

Edited May 9, 2014 by AlanT

[ianc]

With the little TR2/3/3A switch, it was down to engage overdrive. One would have expected the same regime to apply with TR4 onwards. I cannot say for sure because the Works' TR4s used the TR2/3/3A switch as it's much easier and faster to operate with the fingertip than the wand fitted to the TR4.

Better still is an overdrive logic box with a switch requiring almost no movement in any direction, which is what I have been using since 2005 (but I left the small switch in position on the dashboard).

Ian Cornish

[RogerH]

The answer may lay in the USA Their house light switches are up for ON - down for OFF. So the USA TR4 O/D would be up for ENGAGE - down for DISENGAGE.

 

However in most sensible countries we have up for OFF - down for ON.

 

As posted above it is easy enough to swap the wiring over at the switch - relays and logic boxes add to the complication.

 

Roger

[RAHTR4]

I have acquired a new and unused TR4 Lucas overdrive switch from the USA, it was manufactured in 1963 and when fitted to the offside of a LHD car would operate the overdrive by moving the lever upwards.

 

Thus I am sure that the Owner Handbook information regarding the operation of the overdrive switch is correct and what was originally fitted to the cars.

 

Regards, Richard