4-Speed vs Overdrive vs 5-Speed Gear boxes

[The_Doc]

Hello

 

I am currently new to the TR Register and have bought myself a TR4A (solid rear axle option) over the last year and am now in the long process of brining it back to life. This also means thinking ahead and there is a lot to learn! I wanted to see people's opinions on what the best option is with the gearbox.

 

My car came with a 4-speed gearbox and I was considering overhauling this to use. However, my options are keep the 4-speed, upgrade it with an overdrive or put in a 5-speed gearbox from an old Ford. What are peoples recommendations/opinions?

 

Thanks

 

Adam

[Chilliman]

Hello Adam & welcome,

 

You are likely to get some opposing views on this subject but for me the option of a four speed box with an overdrive is the winner, a lot will probably depend on how you are going to use the car and your own driving style, the overdrive gives you the ability to split 2nd/3rd - 3rd/4th & have a 4th+. If you use the O/D properly it makes for a great addition to the overall driving enjoyment.

[TR 2100]

Adam,

 

Welcome to the Forum and the world of TR motoring.

 

Overdrives are expensive - and with good reason - they

transform the car. It's much more than an extra gear for

cruising - it changes the (spirited) way you drive the car.

(and the live axle TR4A is much better for that)

 

The initial cost can be offset against the increased value

of the car as well as the greatly increased driving pleasure.

 

AlanR

[RogerH]

Hi Adam,

welcome.

Simply compare what the choices do and then go for the one that suits you.

 

Straight four speed box - you can have good acceleration or top speed (depending on the diff) but you can't have both.

OverDrive box - complete flexibility - 1/2 gears on top of 2nd, 3rd and 4th. Good acceleration and good top speed (to a degree) usually good MPG.

5 speed box - depending on the box you can have good top speed and or MPG. Lower down the gears it will move you forward.

 

I prefer the OD option but have had a straight box and thought it worked well for my style.

 

If you go for the OD buy in a complete gearbox and OD and sell your old gearbox.

Converting your box will still be expensive.

 

You will be looking at £1000 or so.

 

Roger

Edited October 14, 2015 by RogerH

[ianc]

With a 3.7 rear axle, an overdrive box will allow you to exceed 60 mph at 5000 rpm using only one gear shift (1st to 2nd). When overdrive is selected on 2nd gear, the shift should be immediate and acceleration remains continuous - this is particularly useful on hill climbs.

Despite the cost, in my book there's no contest - a TR without overdrive is not really a TR.

Ian Cornish

[Steves_TR6]

No dispute so far, overdrive!

 

I had a 6 without overdrive previously, and whilst it was great fun to drive on 'slow' roads it was tiring and thirsty on a motorway.

 

Current car with overdrive is even more fun on country lanes, often third and overdrive is all I need, and hugely better on a TRip.

 

It's your choice but for originality and fun and resale value you can't beat overdrive.

 

Steve

[Rob Salisbury]

Adam, the question has to be why settle for a 5 speed box when you can have ,with an A type overdrive, a close ratio 7 speed box? ....You need never be in the wrong gear again, Triumph really did get this one right!!

Cheers Rob

[mike3739]

+1

[Guest ntc]

_{Overdrive 3 rd and none overdrive fourth there is nothing in it so your choice.}

[Alec Pringle]

Whatever 5-speed box you might slot in, it will ultimately devalue the resale value of the car - significantly . . . . .

 

Cheers

 

Alec

[Guest ntc]

Whatever 5-speed box you might slot in, it will ultimately devalue the resale value of the car - significantly . . . . .

 

Cheers

 

Alec

Hi Alec

On that i disagree sorry why do most moderns not have an overdrive fitted?

Edited October 13, 2015 by ntc

[Superaquarama]

On that i disagree sorry why do most moderns not have an overdrive fitted?

 

Cost, presumably. But give me an overdrive over a 5 speed any day, particularly on a TR.

 

I'm sure too that a 5 speed will devalue a TR, as Alec says. Although it may not do so on something that never had an o/d option, such as a Consul Capri or Corvette.

[Kevo_6]

I find overdrive great fun and especially now that I have the logic device fitted.

[MikeF]

For the manufacturer an overdrive unit with its clutch gears solenoids etc is expensive compared to simply adding an extra gear or more in the existing box. But if you think about it modern auto boxes are in some ways a group of overdrives. Certainly I find people understand an o/d if I just tell them its like an early form of flappy paddle gearbox.

Of course you can still get overdrives for some commercial vehicles and land rovers. In the TR it's very satisfying to just flick the lever and welly past someone,and I often find myself wishing I had it on my modern,

 

Mike

Edited October 13, 2015 by MikeF

[Alec Pringle]

Hi Neil,

 

the drivetrain spec of modern vehicles isn't relevant - I was referring specifically to the value of a TR4A.

 

The same logic applies to any TR2-6 equipped with its original type engine and in an overall specification reasonably similar to original - replacing a standard 4-sp 'box with an equivalent o/d 'box is likely to enhance resale value, whereas fitting a modern 5-sp box is likely to detract from resale value.

 

Different matter if the TR is a hotrod with whatever other variety of motive power, drivetrain to suit and the market will decide the value, it's a one-off.

 

Wedge buyers are perhaps less concerned about an OE LT77 'box, especially if the car has a powerful engine.

 

Cheers

 

Alec

[TR5tar]

Another +1 for overdrive. I'd not had any experience of using overdrive until I bought my TR, but now I couldn't imagine not having it. If nothing else, it seems to make for a more authentic TR experience.

 

Darren

[TorontoTim]

To provide the alternative view...

 

I have had cars both with and without Overdrives and, although there are clearly differences, I wouldn't argue that one is especially "better" than the other. The main thing depends on how you will use the car and what kind of driving you like to do.

 

With the way I have driven my cars in both the past and the present (which includes quite a lot of rallying and a lot of backroads driving) there's no question that an overdrive is fun and can be a little quicker (although I've never been too slow without one); but it's also pretty busy. I guess that "busy-ness" is part of the argument for the driving experience. On the other hand, a TR engine is a lovely flexible beast with loads of torque; one of the things this means is that there isn't (in my opinion) a need to keep it in a relatively narrow rev band which is, of course, one of the key benefits of a multi-speed box (I also think it can be a bit "fussy" to be changing ratios that often).

 

Ultimately, I don't find any NEED for an overdrive (my current TR4 doesn't have one) and the main arguments against are extra cost (not insignificant); more complexity and, arguably, fragility. My arguments in favour are potentially higher resale value (as noted by Alec et al, above) and better highway cruising. Having said that, if you spend a long time in a TR on the highway then you're not driving it in the places where it's fun anyway, so..........

 

I appear to be in a minority and it's fair to say I wouldn't take an overdrive out if it had one. But I've had mine for several years and, even though my last TR4A had overdrive as did my Vitesse rally car, I have not thought it important enough to add one.

 

Ultimately, it's your call and as I expect you're going to need to carry out a major rebuild to the box anyway, if the extra cost for an OD box fits your budget you would be normal if you chose to add one ;-)

 

Contrarily,

Tim

Edited October 14, 2015 by TorontoTim

[Mark1965TR4aBRG]

100 % Overdrive

 

It's how the TR should be and for sure the spread of gears and od clutch free up shifts sound superb with a full sports pipe.

[TriumphV8]

I have both versions in use and in addition we have no speed limit on highways.

I have the boxes under all conditions in use.

 

So the 4-speed box is not a good idea because we get mad when driving faster

on the highway. Besides the noise its a bad feeling when the engine revs 4500

without much load but it can be recommended for people who only use it for

some sunday cruises on sunny days. Its quickly and cheaper refurbished

and lighter and does not rob power.

 

4-speed OD eats power and will fail sooner or later on sporty use

but I like the pleasant way of driving and switching the gears,

it is perfect for relaxed cruising.

 

5-speed box on the Rover was the only one to withstand the power

and I like that I can do with the car whatever I want without worrying

that something will break. Perfect for motorsport and hard driving.

 

I do not think about the marketprice of the car. I do not want to sell

one of them but want to establish my personal best way of driving.

If you only do to the car what other will like and pay for it you may loose

a lot of fun if you are not on mainstream......

 

I also do not think about both of them being oldtimer because I bought

the first as a used convertible and not mine but only the others view

and opinion on the car changed during the years.

[Ragtag]

I do not think about the marketprice of the car. I do not want to sell

one of them but want to establish my personal best way of driving.

If you only do to the car what other will like and pay for it you may loose

a lot of fun if you are not on mainstream......

 

 

Totally agree with the above sentiment and more so, if you are rebuilding a car from parts, rather than having spent a fortune on a 'show stopping original'.

 

Let's face it, very few TRs are original now, it's just a matter of degree.

[The_Doc]

Thanks all for your help. There is a lot of food for thought throughout the thread.

 

I'll have a think about what the best course but I have always been leaning towards putting in an overdrive as I want to try and do some touring, which would involve a lot of motorway driving. Plus I want to feel what's it's like to drive the car as it would have been when bought back in 1966!

Edited October 14, 2015 by The_Doc

[Guest]

I started my TR3A's restoration with the purchase of a alloy fuel tank and a overhauled g/box + overdrive. So I was an overdrive fan from the start. Before I owned the TR, I had a Spitfire 1500 with OD, a TR with OD is then a small step off course.

 

I've driven the restored car for a few years now. In case I would have to reconsider choosing a OD box or a 5 speed box, I am not so sure that I would go the OD route again! There are lots of bits and bobs inside the OD box that need constant attention - just check all the topics about OD boxes. (guess I've been lucky so far). Ford or Toyota 5 speed boxes are bombproof and the gear set up is very useable when driving on A or B roads.

 

Here's interesting info: http://www.hvdaconversions.com/about.html

 

Menno

[Chilliman]

Adam,

 

if you need more convincing, join the TR register and go along to one of the local group meetings, there's normally a wealth of experience and more importantly people with O/D cars to play with?

 

Whereabouts are you?

[ianc]

I don't understand Menno's statement that:

There are lots of bits and bobs inside the OD box that need constant attention.

Whilst it's true that the solenoid can fail (and can sometimes be repaired) and the internal clutch will eventually wear out, I don't consider the overdrive as being a source of significant problems.

However (!), my TR4, in which I use overdrive a great deal on all 3 gears, has eaten 3 overdrive relays in the past 22 years - although fitting a replacement is not a big job, just a bit fiddly because of the amount of extra electrical kit which was mounted on the bulkhead in 1962 (four 4-way fuseboxes and 4 relays).

Ian Cornish

[Alec Pringle]

Ian's suggestion that " a TR without overdrive is not really a TR " seems more than a tad contentious . . . . . ?

 

Perhaps the Registrars might care to comment on just what proportion of TRs were built with overdrive ex-factory ?

 

I can recall looking for a TR3 or 3A back at the end of the 60s, and precious few had overdrive fitted, and looking for a TR6 in the mid-70s there weren't many cars in my price bracket that had o/d either.

 

It wasn't a cheap optional extra after all ! In today's money, equivalent to £1300 in the 1950s, falling to more like £900 in the latter 60s.

 

Cheers

 

Alec