4 spd to 5 spd conversion

[TomB]

I have found a advert for a 1995 Caterham 7 1600 Classic SE, 4 Speed Live Axle, approx 8600 miles, BRG at a reasonable price. However I am ideally looking for a 5 speed box as I will be using it as my main car.

 

How easy is it to convert a 4 spd to a 5 spd? I dont fancy pulling the engine out & changing the box myself. Are there any professional concerns that would be able to it? Would it be costly?

 

Basically, should I pursue this advert and live with a 4 spd, or somehow convert it later to 5 spd? Or should I just wait for a 5 spd to come along? How important is a 5 spd?

 

Would appreciate comments from 4 spd and 5 spd Xflow owners.

 

[Violet Elizabeth]

Tom,

 

As usual the answer is "It depends" ! If you are planning on doing many motorway crusing miles then a 5th gear would be nice.

 

For backroad blatting, the four speed is ideal for the wide band of power delivery of a crossflow, you don't need to constantly change gear like you do with these new fangled jobbies tongue.gif.

 

If you can cope without 5 gears, there are better things to spend the money you save on, such as suspension mods / tyres etc

 

I have never felt the need to change from a 4-speed, no doubt others have done so (and will put up convincing arguments), my guess would be SPC or BGH would be the people to speak to.

 

Hope that helps.

 

Nigel.

 

Edited by - Noger on 25 Mar 2002 17:11:08

[EFA]

Tom,

 

There are not many Xflow engined 5 speed cars around. Anything built after about 1994 has a universal chassis which means the 5spd goes straight in.

 

The easy way to cheack this is to look under the car and see if the plate to which the rear gearbox mount is bolted has two sets of fixing holes on the chassis. The second set are for a 5 speed.

 

Basically the 4 sped box has a better (faster) change, but the 5 speed will reduce engine rpm at high speeds (when cruising on a Mway for ex. as Noger says)

 

 

 

 

 

Fat Arn

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[Taran Las]

Tom,

 

Alan Dixon (MAD AO) has the 4 speed sport box and swears by it. I have a five speed but don't use 5th much except for cruising down the motorway(which isn't very often!)Hopefully see you Wednesday.

 

Regards

 

Phil Owen.

 

Edited by - taran las on 25 Mar 2002 21:21:45

[philwaters]

I don't think a 5sp will hold much of a premium over a 4sp to make it worth the time, effort and money doing to job yourself.

If you do you would need the universal chassis to avoid needing mods done at Arch, a 5sp bellhousing, new clutch arm, bearing and I think the input shaft has a different number of splines on it so the little bit in the engine to accept that... and of course a 5sp box. You will then find that your propshaft is the wrong length and might not mate up to the gearbox end... (not sure on this last bit). And your diff ratio will be matched to the 4sp! It all adds up.

Personally not really worth it... I have always had a 5sp on my x/flow and when blatting only went up to 4th... so depends what you want the car for.

 

Phil Waters

Zetec is in and running wink.gif

[Bradbys]

 

I have used my xflow as my only car in the past, including living in Denmark, and for the sake of your eardrums, sanity and fuel 'economy', I have to recommend the 5spd.

 

Even when blatting, fifth gear is used regularly.

 

However, I suppose it all depends on your budget, and how long you are prepared to wait for the right car to turn up.

[Nick Chan]

I have had both 4 and 5 speed boxes in different cars with the 4 speed one being my main car for quite a while back in 80's.

 

Certainly for blatting around the lanes now with the 5 speed, I spend most of the time in 3rd and 4th but even so when you get stuck behind the old dears on the single track roads around the countryside, 5th is a bit more relaxed!

 

Likewise on the motorway, it drops the revs just enough to be less buzzy (technical term, there!) and a bit more suited to cruising along...

 

Not sure about the chassis mods but the work to take the engine out and replace the box is very straightforward stuff. If the price is right for the car, I'd buy it and then think about any changeover after you have had chance to play... and that could be quite a while!

 

Nick

[Violet Elizabeth]

Or you could buy a set of ear plugs smile.gif

[TomB]

Cheers for your help guys. How about a 3 speed automatic? ;-))

 

[Bricol]

Did this in a Westfie1d - easy peasy and used to use 5th a lot - even at 30 mph cruising into work.

 

(1600 X-flow on webers, daft cam, BIG valve head)

 

Used Sierra box, bell housing, clutch arm, release bearing etc.

 

used X-flow clutch apart from friction plate - used a Mintex part (can get the number- its at home) which I believe came form a Humber of all things!

 

Box linked perfectly to engine - had to get a new prop - 80 quid from propshaft clinic here in Bradford - told them the length and what it had to connect to - easy.

 

Ran fine for the 7 years with me - sprints, autotests, 10000 road miles a year, production car trials (lots of clutch work!). As far as I'm aware, still okay with current owner.

 

Which is why I now miss the torque of the X-flow (K-series doesn't like setting off in 2nd!) and the overdrive fifth(6spd box - a touch noisy!).

 

Do it - easy to do and makes a world of difference to enjoyment on normal roads in normal driving. And makes no difference to "blatting" - infact I used 5th a lot even then - even managed to get into 5th approaching hairpin at Knockhill as it was hitting the limiter in 4th!

 

Bri

[Allan Haighton]

Tom

A 1995 Classic SE probably won't have a 'universal chassis' - mine doesn't.

This was the crossover period in chassis design - the scholarship cars in 1995 did get the 5 speed box, but Caterham woulddn't sell me 5 speed chassis when I ordered mine.

 

With the older chassis layout, you'll need to make some mods to get the 5 spd box in, and shorten the propshaft too.

 

Allan