Superseven Twincam Posted December 1, 2003 Share Posted December 1, 2003 Hi Guys, (and the occasional Gal) This January, along with other repairs, I wish to lengthen the gearing of my S3 by some 10-15%. As the gearbox will have to be taken out for the synchros, I'm thinking of altering the gearing on the box. I don't know where the speedo is driven from, so not sure if I'll have to alter the speedo or it's drive as well. I've understood that alterations can be made through the gears itself, or the axle that drives the differential. Someone mentioned some adress where different sets of gears were obtainable for these early 4-speeds? Appreciate the input, Jilles. Link to comment Share on other sites More sharing options...
Chelspeed Posted December 1, 2003 Share Posted December 1, 2003 Virtually all upgrades to the 4 speed gearbox will just change the lower gears (raise them and bring them closer together) and will leave 4th at 1:1. Worth doing in it's own right as standard ratios don't really suit the Se7en but will not affect overall gearing. To change the gearing overall you will need to change to a different diff ratio by changing the cwp (crown wheel and pinion) in the axle. To get an overall gearing change from the gearbox you could fit a five speed which has an overdrive top, 0.87:1 if I recall correctly. But this is a big change, far more difficult than a cwp change. If you do change the diff ratio then the speedo will read wrong as the speedo is driven off the gearbox output shaft, ie before the diff. You can correct this to some extent by changing the little plastic driven gear in the gearbox for one with a different number of teeth. The driven gear can be found under the big tin plug on the left side of the back of the gearbox. Edited to say that Quaife do gear sets here Edited by - Chelspeed on 1 Dec 2003 10:09:53 Link to comment Share on other sites More sharing options...
deanteam Posted December 1, 2003 Share Posted December 1, 2003 As Chelspeed says, it is impossible to change the overall gearing unless you go for the 'overdrive' 5-speed. If you go for a rear axle change, there are different speedo gears that fit in the gearbox. I think they are listed in the Wheale book. There are a couple of different 4-speed boxes, we run 3-rail boxes and spares can be a bit difficult. I get syncro rings from SPC and have got straight cuts from Tranx. Burton is also possible for some parts ( Quaffe gear sets). If you look at their brochure they have explaination of the type of gearboxes. www.burton.com. Link to comment Share on other sites More sharing options...
Superseven Twincam Posted December 1, 2003 Author Share Posted December 1, 2003 I've sent an E-mail to Quaife and will have a look at what they've got to say. I'm aware that fitting a 5-speed will involve some drastic modifications and have decided not to go that way in view of originality. I wasn't aware that the speedometer-drivegear could be altered, to be honest. Think Chris K. mentioned the possibility of changing the gears of the four-speed, so that stuck in my mind, but forgot the mentioned company that did that? I hope Quaife will be able to supply me with a set of gears that'll take care of the lower gears as well as overall-gearing; the gearbox will have to be dismanteled anyway. If not -likely-, I'll go for the cwp-change. Thanks again and I'll keep You posted! Jilles. Link to comment Share on other sites More sharing options...
Superseven Twincam Posted December 3, 2003 Author Share Posted December 3, 2003 Company mentioned before is BGH. Quaife sent me an offer for a 4-speed clubman synchro gearkit, amounts up to almost 500 GBP; quite a lot of money. Not possible to have the gearing raised so fourth will be less than 1:1, so I'll have to go for the cwp-change-as was to be expected. Clubman kit is; 1; 2.48 / 2; 1.69 / 3; 1.21 / 4; 1:1 (suggested) Standard 4-speed for Caterham is NOT the RS2000 box as mentioned, sorry 'bout that. It's the Ford 116E Cortina gearbox. (As mentioned in Lotus and Caterham seven; Racers for the road by John Tipler) Gears of this 'box are; 1; 2.97 / 2; 2.01 / 3; 1.40 / 4; 1:1 I'll have to look into the costs once the gearbox is dismanteled, then make a descision whether or not to go for the clubmans kit. Have to say that just changing synchros and cwp sounds like a much more "economic" solution, taking the standard gears for granted? I'll send BGH an E-mail and see what they've got to say... Wouldn't want to dissapoint all of You for NOT behaving like a real Dutchman. LMFAO!!! Jilles. Link to comment Share on other sites More sharing options...
deanteam Posted December 3, 2003 Share Posted December 3, 2003 I think the Lotus-Cortina version of this gearbox had better spaced ratios, similar the the Quaiffe set. I think the Quaiffe set might be straight cut, no major problems but whines in the first three gears like a proper old'n. Link to comment Share on other sites More sharing options...
Superseven Twincam Posted December 4, 2003 Author Share Posted December 4, 2003 BGH charges about the same as Quaife does... Link to comment Share on other sites More sharing options...
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