Tech:Engine/K Series/Gearboxes

There are a few options for adapting a gearbox to a K series motor, So here is a guide is to what is out there..

K40/K50 (Toyota Factory 4/5 Speed manual)

The K40 or K50 gearbox was factory fitted behind 3K/4K/5K motors. They are the most common gearbox in early KE Corollas. TRD gearsets were available for K50 gearboxes.

T40/T50 (Toyota Factory 4/5 Speed Manual)

The T50 gearbox is a lot stronger than the K50 gearbox and is a split casing design. You can still purchase close ratio gearsets for the T50 gearboxes through TRD and also Quaife. The T40 or T50 gearbox can be adapted to a K series motor with a K-T Bellhousing,

The K-T Bellhousing came in a few different forms...

1. Cable clutch K-T Bellhousing, Extremely rare, Easier to install in earlier KE Corollas as you don't need to install a hydraulic clutch (Pictures courtesy of Xany and tojo2).

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2. Hydraulic clutch K-T Bellhousing, Rare, Requires hydraulic clutch setup to be installed. (Off KT174 5K T40/Carina, KT14x series Corona)

CLUTCH FOR K-T50: Although the K-T50 bellhousing in any form is very rare, nearly every clutch manifacturer make a kit for it. When looking for a ke20-70 clutch kit you may be asked "is it a 19 or 21 spline?"

All post ke20 K40 and K50 gearboxes have a 19 spline input shaft, with a 180mm diametre clutch plate. Hence the clutch dimentions are 180x21.6x19T - where 21.6mm is the input shaft diametre. These are listed as "most 4 & 5 speeds". This is the exedy listing for a K40/50 clutch.... http://www.exedy.com.au/SpecSheet.aspx?SpreadsheetRowId=40330

The T50 box has a 24.1mm input shaft with 21 splines, this is the 21 spline kit you may be asked if you have. It still bolts to a stock 3k/4k 180mm flywheel, hence the clutch dimentions are 180x24.1x21T. Here is Exedy's listing for the K-T.... http://www.exedy.com.au/SpecSheet.aspx?SpreadsheetRowId=40331

You may also notice that between different clutch manifacturers the middle number in the dimentions (input shaft diametre) may be different. For example PBR list the K-T50 kit as 180x28.3x21T. This is because they measure the diametre of the shaft in the vallies, whereas say Exedy measure it on the peaks of the spline.

3. TRD Upright bellhousing, Like the Holy Grail if you can find one, Cable clutch, Designed to allow for the positioning of an upright K motor. If you have one of these please send me some pictures so I can upload them here, Also your address would be great so I can come and steal it :)

Toyota W50 (Toyota Factory 5 Speed Manual)

The W5x (W50/W55) gearbox will fit if you use a K-W bellhousing from a KR42 Townace.

See also:

• http://www.rollaclub.com/board/index.php?showtopic=12935 (How To Fit A W50 To A K Series Motor)

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Article by Medicine_Man / Taz_Rx / Xany / tojo2

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