Tech:Engine/K Series/Gearboxes

From Rollaclub
Jump to: navigation, search

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..


100 1648 Gearboxes.jpg


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).


Gearboxnetresize01.jpg


Gearboxnetresize05.jpg


Gearboxnetresize04.jpg




2. Hydraulic clutch K-T Bellhousing, Rare, Requires hydraulic clutch setup to be installed. (Off KA67 5K T40/Carina, KT14x series Corona)


Sv107233.jpg


2007 0502400096.jpg


2007 0502400097.jpg


Sv107258.jpg


Sv107239.jpg

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 :)


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. Commonly referred to as "some 5 speeds". 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.


GEARBOX SELECTION - Which one to use? There are a few different type of T50 gearboxes, and you need to be selective on which one you use for a K-T. Shifter position: TA22 & T18 T50's share a "ke30-55" shifter position. The AE86 and AE71 T50's have a "ke70" shifter position. TA22 & T18 T50's both also have a 20 spline output shaft, just like a ke20-70 corolla. The gearbox is also the same length so there is no tailshft mods required to use one! The later (AE86/AE71)ones are 22 spline output and will require the tailshaft yoke to be swapped.


Toyota W50 (Toyota Factory 5 Speed Manual)


The W#0 (W40/W50) gearbox will fit if you use a K-L (L40) van bellhousing from a KM20-36 Liteace. This bell housing will bolt up to 4x of the 7x bolt holes on a W40 or W50 celica STEEL CASE gearbox, however you will need to grind a small amount out of the back of the bell housing to clear a "welse plug looking thing" on the gearbox - see the below link for pictures of this. I have mine bolted to (see below pic) an RA40 celica W50.

CLUTCH and FLYWHEEL: There is only one option when it comes to clutches & flywheels for this GB combo. You need to use the KM20-36 (beit 4k or 5k) flywheel, clutch fork, throwout bearing retainer, and clutch kit. The flywheel on a litace has the same overall diametre as a corolla one, however it has a bigger 200mm clutch plate surface. The W50 input spline is the same as a liteace one so it all then matches up. Clutch dimentions are 200x29.8x21T and here is the exedy listing..... http://www.exedy.com.au/SpecSheet.aspx?SpreadsheetRowId=14772 Even though this is a 'light commercial' clutch kit, exedy still make a brass buttom option!!!! hahaha - That would be fun in a loaded up van!!! Just like the liteace, this gearbox combo still retains a cable clutch system.

SHIFTER POSITION: The W50 that I am using has the same shifter position as a ke70, so fitting one in a ke30-55 will require a bigger shifter hole.

TAILSHAFT: The W50 GB is the same overall length as a K40/50, so no tailshaft shortening/lengthening is required. However the output spline is MUCH bigger and a corolla tail shaft needs to have the RA40 yoke transplanted onto it. This can be done with an old Holden (of all things) uni joint!! (Pictures courtesy of Taz_rx)

DSC03137.jpg


DSC03138.jpg


DSC03139.jpg


100 1083.jpg


See also:


W5X (Toyota Factory 5 Speed manual)

This option is probably a bit of an overkill for a K series motor, but by using the bell housing from a G5# 5speed van gearbox, KR42R (7kc/e powered) townace or KM3# etc, allows you to fit a W55, W56 etc celica/supra ALLOY CASE GB. To do so you will need to use the townace flywheel, clutch kit, fork and retainer, as well as the slave cylinder as this is a HYDRAULIC ONLY clutch. The townace 7k flywheel is still the same overall diametre as a corolla one, but has a bigger again 215mm clutch plate surface, so clutch dimentions are 215x29.8x21T, again here is the Exedy listing... http://www.exedy.com.au/SpecSheet.aspx?SpreadsheetRowId=14829 Suprisingly again there is a brass button option.

Below is a W56 from a KR42R, still attached to a 7KC.

W56.jpg



Article by Medicine_Man / Taz_Rx / Xany / tojo2



Back to K Series

Back to Main Page

Rollaclub