Conversion Components

We recommend a qualified automotive technician should install this product.

Warranty

Gearboxes are Ex Japan - 2-month return warranty, and are supplied complete with gearlever, slip yoke, rear rubber mount. No warranty on geartooth breakage.
Conversion Components can not be held responsible for consequential loss.
A little bit of knowledge can be dangerous.

1. Flywheel clearance check

Check that engine has its original alignment dowels, protruding from the rear face of the engine. With flywheel assembled to engine, fit bare bell housing to engine and bolt on with at least 2 bolts. Turn over engine and listen for any interference between ring gear teeth and bell housing. If there is any interference grind away inside area of bell housing concerned, and re check for clearance. Check length of bolts for correct entry length into engine.

2. Assembly of Bell housing to gearbox SUPRA gearbox

Check that the 2 - ø12 dowels are removed from gearbox (stepped dowels are fitted to bell housing) Fit bell housing to gearbox and fit M10 fine bolts & tighten. In some conversion bell housings, different length bolts are supplied. Pre check these - they should protrude from bell housing between 20 - 25mm. Tighten bolts. Locktite can be used if desired. Fit clutch fork, and thrust bearing (set up correct measurement, refer drawing) using suitable lubricant on moving faces. For hydraulic clutches, bolt on slave cylinder.

3. Proper alignment of bell housing to engine

It is very important to ensure that the bell housing is correct in line with crankshaft of engine. Check on engine that the correct dowels are protruding, as fitted by the original engine manufacturer, and that they are in good condition, are not 'loose'.
Chev V8 - 2 ø5/8". Ford V8 - 2 ø1/2". Ford 4 cyl - 2 ø1/2" hollow. Lotus - 2 ø15.
Rover V8 - 2 ø1/2". Daimler - 2 ø3/8". Jaguar - 2 ø3/8". MGB - 2 ø5/16" full bolts. Healey 3000 - 2 ø3/8" full bolts. Triumph Spitfire - dowel upper, bolt ø3/8" lower. Triumph GT6, dowel upper, bolt ø????". Triumph TR2-4 - 2 ø3/8" dowels. TR6 - dowels in bell housing.

4. Input shaft bearing

Check original type bearing in rear of crankshaft. For some conversions a replacement bearing will have been provided. Fit this in the normal manner. If an input shaft sleeve has been provided, gently tap it into the end of the input shaft, being careful to keep it in line (turn shaft).

5. Clutch assembly

Assemble clutch plate and pressure plate in the usual manner, ensuring that the clutch plate spline is in line with the crankshaft. If needed turn up a wooden alignment piece.
Measure from engine face to pressure plate fingers. This is dimension 'A' (refer drawing above).
Measure from bell housing face to thrust bearing in rear position. This is dimension 'B'. Dimension 'B'should be greater than dimension 'A' by 5 - 6mm to give clearance for clutch wear. If this dimension difference is above 6mm the fork pivot post can be packed out with 2 - 1.5mm washers, or adjusted, or another thrust bearing carrier could be fitted.

6. Assembly of gearbox to engine

Remove gearlever from gearbox, put into a gear. Place a wad of paper into gearlever hole to prevent anything falling into gearbox. Lift up gearbox - bell housing assembly to engine, being careful to slide input shaft into clutch plate spline hole. When entered - check for general alignment of gearbox to engine. Push gearbox to engine and ensure that rotation is correct so that dowel holes will line up with dowels.
If necessary turn output shaft so that spline on input shaft engaged in clutch plate. Fit bolts and tighten evenly to pull bell housing up to engine. Check that clutch lever has some free play.
Connect up slave cylinder pipe & bleed, or cable to clutch fork and adjust. Depress clutch pedal until gearbox output shaft can be turned. Clutch pedal should only travel another 13 to 20mm further in. If travel exceeds this then pressure plate could suffer damage. In some instances it is helpful to screw a packing block to the floor of the vehicle, or limit total length of clutch pedal travel.

7. Check that clutch plate releases

This also checks that end of input shaft does not have any interference with crankshaft. (Which can cause major problems)

8. Cross Member

Jack or pack up gearbox to correct height + 6mm, for clearance to hole in floor for gearlever, and clearance for drive shaft. Take original cross member from vehicle and determine if it is suitable to modify to suit conversion. A U shaped bracket can be made to suit the Toyota rubber gearbox mount. If made this bracket should be made from 3.0mm plate. (To comply with certification requirements). Strengthening side plates will need to be added and all joints fully welded. Cross member should be at least as strong as original or stronger. Fit to rubber gearbox mount with M8 hex head screws.

9. Drive Shaft

Measure from rear face of gearbox to reference point on differential of vehicle. Record measurement. Measure driveshaft and Toyota universal yoke. Work out length required allowing clearance (20mm). Cut driveshaft tube, machine-sizing tube if required, assemble and weld in correct alignment & rotation position. Balance & paint. Fit to gearbox & differential.

10. Speedo Cable

Remove original speedo cable and fit conversion cable. Ensure that it is carefully re routed to suit the Toyota gearbox connection, and that sufficiently mounted to the chassis. Keep bends with as larger a radius as possible. Speedo calibration is customers care.

11. FILL WITH OIL

12. Reverse Light

Connect wires to reverse light switch and check for correct operation.

CELICA GEARBOX

This gearbox is located to the bell housing by a ø106mm nose cone. Fit bell housing onto the location nose cone and insert the M12 fine bolts into the holes. Check on length of bolts that they don't bottom out on the blind tapped holes. Tighten bolts.

T50 COROLLA GEARBOX

These gearboxes have either f 62 or f 68mm input bearing, nose cone. The 62mm has a round base to the nose cone. The 68mm has a square base to the nose cone. New gaskets are supplied with the bell housing kit. Apply gasket sealant to gearbox face, fix gasket and offer bell housing carefully over input shaft. Align holes of both parts and then fit M10 bolts that came out of gearbox. The spacer that fits the layshaft is not required with the conversion bell housing. Tighten. Fit pivot post for clutch fork, with locktite and tighten. Insert input shaft spacer, fit gasket to nose cone and assemble with M8 bolts. Use a gasket sealant on these bolts as oil can work down the thread & leak. Tighten bolts.

For MG Midget - 4K conversion refer MG Midget.

Location and Identification of TOYOTA 5 SPEED GEARBOXES

W55 - W59 SERIES - "SUPRA"

From 1985 onwards
Fitted to 6 cylinder cars 2000cc up to 3000cc (single turbo).
Out of Celica, Supra, Cressida, Hilux 2WD and others,
(comes in floor shift and column shift).
No real markings on gearbox.
At front has 9 bolts, 2 dowels, 250mm high, 197mm wide.
Several gearlever positions. 455mm, 515mm, 530mm, from front face of gearbox.
(3 options on driveshaft yoke size)
34 Kg dry weight.

R154 SERIES "BIG SUPRA"

Fitted to 3000cc Supras, single turbo and all twin turbo
From 1987 onwards.
No real markings on gearbox
At front has 9 bolts and 4 dowel positions, 265mm high, 226mm wide.
45 kgs dry weight

T50 SERIES

All alloy, and split joint like a suitcase.
7 bolts at front and bell housing acts as front cover seal
Input bearing varies ø62 (nose cover - round) ø68 (nose cover - square)
(Conversion bell housing has to match the bearing size)
Output spline varies depending on bearing size.
2 gearlever positions, 390mm and 490mm
No real markings on gearbox
27 kg dry weight

Colin Dray
Conversion Components
Waihi, New Zealand