Caterham 6 speed box

[letterkenny]

Hi all,

about to remove my engine and type 9 box to fit a six speed to a '94 1.4 supersport. Does anyone know if the input shaft on the boxes fitted to the duratec r400 race cars is compatible with this engine????

Cheers for any help / advice

Ken

[sfaulds]

The shaft is the same, but you'll need to change the nose casing for the CRB to run on.

[letterkenny]

Hmm. Not come across a nose casing before, is that the front part of the gearbox or a bellhousing part?? Sounds like this may be getting out of my depth. Engine has to come out anyway as the ring gear has moved on the flywheel...grrrr. If this will involve a gearbox rebiuld I might be better off selling this box and sourcing another 6 speed or a close ratio type 9. Basically wondinging if a nose casing change is a big job???

[EFA]

Nose casing is 4 M6 bolts. Takes about 2 mins!

The nose casing is the sleeve on the input shaft along which your clutch release bearing runs (assuming you do not have a dry sump.

Y0ou can see the nose casing on the front of these two gearboxes here http://img9.imageshack.us/img9/9931/strikergearbox... and the part here https://www.caterhamparts.co.uk/product_info.php?p... - you will get one for much less - give Road & Race Trans a call 01959 525105.

[Dave J]

I'm not sure if it affects this installation and not wishing to scaremonger, but I had to use a shorter input shaft (minus 17mm iirc) when i changed from k series to duratec . this required a whole new input shaft in the gearbox.



dj

[Dave J]

ps this was for a short bellhousing install . I assume the r400 duratec race cars use the longer bellhousing (same depth as k series) following Stuarts comment ?

dave

[EFA]

1.4 K-Series definately uses long input shaft, unlike 1.6 and 1.8 versions.

Not sure about Duratec race cars.


Dave, have you not heard of chopping off the end of the shaft? Quickly and easil accomplished. I did it on several 1.4K upgrades I got involved in.

[sfaulds]

I wasn't aware there was a short version of the 6 speed input shaft available - ISTR trying to find one the last time I used a short bellhousing. I also looked into shortening the shaft and turning it down to suit, but they're hardened, and I wasn't entirely comfortable with the length of splines I'd have left.

The 1.4 uses the same length shaft as the 1.6/1.8 - it's the same bellhousing.

The Caterham Duratec install uses the same length shaft too.

[V7SLR]

Just to add to the comments by EFA and sfaulds ..... as far as the k-series is concerned, any gearbox built to fit the 1.6/1.8 will also fit the 1.4, however if the box was originally built for the 1.4 it "may" not fit the others without reducing the input shaft slightly, usually around 13 to 17mm. There's a little extra depth beyond the spigot bearing in the end if the 1.4 crank probably bored out to easily fit with Caterham's supply of type 9 boxes.

[letterkenny]

Many thanks to Stuart, Dave and EFA. Thats really helpful, had seen lots on Blatchat re type 9 input shafts but very little regarding the 6 speed box. Will aquire the nose piece and get the motor going again.

Cheers, Ken

[Dave J]

I know about chopping the end off the shaft when swooping between k series models, but we are talking here about the op buying an ex duratec gearbox and fitting it to a k series

the duratec has two options of bellhousing sizes

the shorter bellhousing brings weight distribution benefits but as Stuart said I had to get a new input shaft machined down on the splines to account for the shorter bellhousing

my point was for the op to check the input shaft for fitment

Stuart has confirmed that the Caterham install uses the long bellhousing

dj

[EFA]

sfaulds said:

I wasn't aware there was a short version of the 6 speed input shaft available - ISTR trying to find one the last time I used a short bellhousing. I also looked into shortening the shaft and turning it down to suit, but they're hardened, and I wasn't entirely comfortable with the length of splines I'd have left.

The 1.4 uses the same length shaft as the 1.6/1.8 - it's the same bellhousing.

The Caterham Duratec install uses the same length shaft too.

The hole in the back of the crak is deeper on the 1.4 hence the longer input shaft. It is only the part of the inbut shaft which sits in the spigoit bearing which is longer. Splines are the same on all types.

Nige

Dave - I guess the spline length will vary in this case then.

Anyway, glad we could help the OP.

[Mars]

EFA said:

Nige

Not me I'm afraid. V7SLR is now under new management.

[V7SLR]

EFA said:

The hole in the back of the crank is deeper on the 1.4 hence the longer input shaft. It is only the part of the inbut shaft which sits in the spigoit bearing which is longer. Splines are the same on all types.

The position of the spigot bearing and the section of the shaft that runs in it is the same for all 1.4/1.6/1.8K variants - the extra length of the input shaft just rotates in free space in the 1.4 crank. If the input shaft was chopped (appropriately!) it wouldn't make any difference in the 1.4 install.

Not relevant to the OP question, but information that is worth sharing!

Stu.