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Overdrive gear knob


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I went to my local register meet a couple of weeks ago and saw a car that had a gear lever knob with the overdrive switch in the centre of the knob.

 

Being a shy retiring and timid person I didn't like to ask how and where :P

 

So can someone please tell me where this gear knob comes from and how this mod is done.

 

Regards John.

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Hi, John. This is the layout in a Stag. I think it might be the same in some Dolomites too but am unsure ( I have seen it but could not establish that it was O.E.).

 

Quite a few TR drivers have done this mod in the past but I don't seem to see as many these days. Speaking personally, I prefer the stalk lever as it enables me to drop a ratio into a fast bend without taking a hand off he wheel.

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Hello John

All late Spitfires,Stags and I think most of the big saloons use this method to switch overdrive in and out.

 

The cables inside the gear lever tend the chaff and short out

 

I wonder if this was done to discourage people from using the J type over drive aggressively and to merely regard it as a 5th gear for cruising as it had already been removed from 2nd gear maybe for strength reasons but I think it would be to slow to engage in 2nd due to the type of operation ie the solenoid closes and builds up pressure and revs are to low were as A type already has pressure built up and ready to engage the clutch.

 

Which also in theory should make the J type more efficient when not engaged ie no pumping up of high pressure.

 

But I may be wrong as I often am!

 

Roger

 

ps now back to working on brother in laws 6 engine(head and cam)then only the gearbox and overdrive to swop over!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! my little Spitfire is so much easier to work on with bonnet open and I don't have to remove the cross brace and move the steering rack to get the cam out? or jack the engine up

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Stag and the various monocoque saloons of the 70s utilised the gear lever with knob switch, so there are plenty around still John, and yes it was OE. Cable drops down the inside of the stalk.

 

Personally I rate this as infinitely preferable to a column or dash stalk for the overdrive - natural place for gear operation, not fiddling about amongst the headlamp and indicator switches on the column, or changing up on the dashboard to overdrive wash/wipe . . . . :rolleyes:

 

Cheers

 

Alec

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Both my lad's Spits and the Dolly Sprint have the gear lever mounted overdrive (as do GT6's and the other Triumph saloons)... Preference on location is no doubt personal; for me it's the column mounted lever on the TR!

 

Cheers

Ian

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I turned mine up from a bit of alloy, incorporates a momentary push button with blue LED when OD selected via a 'logic' controller, gives imediate access to 7 speeds...I prefer to use the gear lever to change gears..... :)

post-3772-0-66789300-1374240015_thumb.jpg

post-3772-0-66789300-1374240015_thumb.jpg

Edited by johnny250
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John

I bought one that Johnny made. Looks like the one in his photo. It was really great. Its not on the car now as I have reverted to steering column location. You will need a logic controller for it because it is a momentary switch unlike the Stag affair.

 

You need a dimmer for the blue LED though. I never fitted one and at night it was like a laser!

Can't remember what I paid for it. If you would like it give me a shout but I am about to go on holiday for a couple of weeks. Then Malvern?

 

Cheers

 

Quentin

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Personally I prefer the overdrive switch on the column - you don't have to take your hand off the wheel to engage/disengage.

My Stag (and a Spit in the distant past) has the gear knob switch.

 

The reason for restricting o/d operation to 3rd and top was not because of the wiring (if it were to get frayed it would be by gear shifting not flicking the electrical switch) but because the J-type allegedly didn't cope with torque as well as the A-type hence the removal from second.

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Interesting Andy......... how do you manage to change your 'regular ' gears without taking one hand off the wheel??

When accelerating hard, with a logic box and button, you can easily run up through the gears with a press of the button as required, 1st, 2nd, 2nd OD, 3rd, 3rd OD, 4th, 4th OD.... one hand steers, the other changes gear.

If desired you can 'hold' OD engaged whilst changing gear (otherwise it disengages automatically) by squeezing the button as you change....fab gear!

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Column mount for me...I only ever use o/d in top gear as an extra ratio so it suits the way I drive.

I don't doubt if you're pushing on the gear stick might be best though...as was said earlier.....personal preference.

Simon

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Following on....maybe it is just me but changing from 2nd to 2nd o/d then 3rd seems pointless to me as the ratio in 2nd o/d is pretty near identical (apart from a few hundred RPM) to 3rd! Why would you do that? (same with 3rd o/d and 4th)

Surely the beauty of o/d is being able to switch up and down quickly and NOT as a normal progression through the gearbox????

Simon

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Simon

 

I also find 3rd O/D and 4th too close together... A logic device would not benefit here, though can see the 'logic' of having one for other ratios - but I'll stick with the original method thanks!!!

 

Cheers

Ian

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Interesting Andy......... how do you manage to change your 'regular ' gears without taking one hand off the wheel??

When accelerating hard, with a logic box and button, you can easily run up through the gears with a press of the button as required, 1st, 2nd, 2nd OD, 3rd, 3rd OD, 4th, 4th OD.... one hand steers, the other changes gear.

If desired you can 'hold' OD engaged whilst changing gear (otherwise it disengages automatically) by squeezing the button as you change....fab gear!

 

Like most cars of the era I press the clutch and move my hand to the gearstick!

Something I don't have to do on the TR when engaging or disengaging overdrive.

 

I rarely use o/d on anything but top unless in traffic. It might be different if the TR had a close ratio box and a suitable ratio o/d when in theory it could function as a 7 speed box. However , as the 6 has a pretty wide power band that wouldn't be a big deal unless using a very wild race cam with a narrow power band.

 

I agree with Ian the standard ratios are too close together to function as a true 7 speed box: the novelty value of the logic switch is soon overridden by the ease of flicking my left little finger!

Edited by andymoltu
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I use OD 3rd a lot. We have many routes around my area that vary from 25mph to 30 mph to 45 mph and back again and flipping in and out of overdrive in 3rd is easier than the constant rowing between 3rd and 4th with the gearstick. So having the OD switch on the steering column makes that a breeze, just extend a finger and flip the switch.

 

Stan

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John

 

You may have to cut and shut the gearlever to get it to sit in the right place if using a saloon one, you cant just change the knob as it is fitted differently on the saloons and dollys to the standard TR screw on type so you will have to change the lever.

 

Cheers

 

ALan

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If you want to fit a saloon gearstick to a TR5/6 type box then you can do a straight swap as the gearlever mounting on the top of the box is the same but if you want to fit it to a 4/4a box then you will need to do a "cut & shut" as the mounting is different. You may also want to give it a bit of a crank backwards as well as the saloon one is straight.

Stuart.

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I started to post about the internal wires, then found that rogerguzzi had already mentioned it. But twice told id better knoe, so anyway....

 

I must presume that when Triumph designed this, they couldn't make a strong enough gear stick unless the hole up the middle was very narrow. So they used wires that were insulated with shellac, basicly varnish, instead of harder wearing but thicker PVC. And when the shellac wears away, the wires short and blow a fuse, usually the one that also looks after the fuel gauge.

 

Surely today we have really thin wires that have plastic insulation? So replace the old ones.

 

An alternative is to mount a switch on the steering wheel. A length of 'curly-whirly' three coil flex provides flexibility and a more reliable earth than the steering column.

 

John

 

post-535-0-02319200-1374398713_thumb.jpg

post-535-0-02319200-1374398713_thumb.jpg

Edited by john.r.davies
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That's what I hoped to hear, Stuart.

So I googled for "thin wall cable" and there's lots, but the thinnest I can find is 11A, 0.5^2mm, that is said to have an OD of 1.5mm.

 

I have a gear stick in my spares, that has an entry hole for the wires halfway up (TR? Saloon??). The hole is 6mm wide, so that could take the 11A thinwall.

 

But on my Vitesse, I have another, differently bored gearstick, on a small chassis gearbox. The hole is all the way through and only 2.5mm wide, so I fear I'll have to stick to the curly-wirly! This must be a Mk3 Spitfire or earlier stick, as they changed to the column mounted switch after that.

 

John

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John

 

When I was sorting out the O/D wiring on one of my lad's Spits, the wiring was found to be domestic twin core cable!!!! As I couldn't at the time get what I wanted to replace the connections on the back of the gear lever mounted switch, I bit the bullet and opted to order the dedicated small loom from Moss or Rimmers (or whoever I got it from). Did the same with the Dolly O/D wiring as that too was highly suspect... Not particularly 'cheap' for what it is, but it did the job!!

 

Cheers

Ian

Edited by ianhoward
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Mine is wired running down the outside of the standard gearlever, as it's hidden inside the gaiter anyway.

Edited by johnny250
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The kind of wire you are using is covered in PVC. This has to be quite thick. Almost thicker than the wire itself.

 

The wire you really want is covered in ETFE.

 

http://uk.farnell.com/jsp/search/browse.jsp?N=2031+202843+110536443&Ntk=gensearch&Ntt=raychem+44&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_UK&divisionLocale=en_UK&catalogId=&skipManufacturer=false&skipParametricAttributeId=&prevNValues=2031+202843&mm=1004790||,&filtersHidden=false&appliedHidden=false&autoApply=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D2031%2B202843%26Ntk%3Dgensearch%26Ntt%3Draychem%2B44%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D2031%2B202843

 

This is much tougher, heat proof, wont crack, easy to strip and the overall diameter of the wire will be smaller because for a given wire gauge more of it will be wire and less will be insulation.

 

The link is for 20AWG which is has a high current rating. You could probably use 24AWG in most places.

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