5-Speed Celica steel-case gearbox to 138 Holden Grey Motor (Stock Manual EK)
After having my stock 3 speed crash box break again this year, I decided to replace it with a Steel Case Toyota Celica Box. A good reliable box for basic engines, and used by several of my car club in their hot rods.....so we've got a little experience in them now. Below is my account of the swap and what is needed. Some sections have been cut and pasted from various on-line info and I've elaborated a lot more on some items that I had to work out myself.What do I need Get / Buy?
1. A steel case celica gearbox complete with shifter and gearstick. Mine cost $100 from a mate.
Note: Be careful with exactly which gearbox you get as there are several shifter positions available in these boxes. Try to get one with the shifter about 2 or 3 inches (50 – 75mm) in front of the rear end of the extension housing. This makes it easier to clear the front to the bench seat. Mine ended up about 2 inches behind the front edge, but would have been harder if further back…
2. The rubber / steel rear gearbox mount for the Celica box. Mine cost $40 from Bursons.
3. A conversion Bell-housing that is suitable for your clutch mechanism type (Mine is the stock EK hydraulic system.) The Bell-housing I used from Dellows allowed the use of the standard 6 cylinder Holden clutchfork, making this conversion easy. (Cost $500) Owch.
4. I replaced the standard clutch fork, and clutch fork pivot whilst I was doing the conversion. (Cost $200)
5. A conversion Speedo Cable. (Cost $50 off eBay)
6. A conversion Spigot bush that fits the Celica box shaft. (Cost $40 through Dellows)
7. A new 8.5” clutch-plate. Mine was from Dellows. (Cost $145 through Dellows)
Note: The clutch-plate can be one for a 1.8 litre diesel Lite-ace van (same outside diameter as a Red 6, same inside diameter/splines as a Celica)
8. 2nd hand (or new) Pressure-plate from a Holden Red Motor, which bolts to grey motor flywheel. I used a 2nd hand one in Ok condition (Cost $20)
9. New Thrust Bearing and Carrier. ($120)
10. Toyota yoke to Holden shaft for the end of the tailshaft. This was sourced from Dellows and allows the standard Holden shaft to be shortened with the new end yoke ($145)
11. New slave cylinder. Mine was fairly knackered.($55 off eBay)
12. Ability or means to refabricate the main X -member. (Car Club Members!)
13. Plus a few normal workshop tools – Assorted spanners, assorted sockets, assorted screwdrivers, etc, a jack, jack-stands (preferably 4 of them), some grease, some gearbox oil, a measuring tape, a drill, and angle grinder.How do I do it?
1. On hard and level ground (ideally on concrete), jack up your car and place it on jack-stands front and rear. Make sure the jack-stands are stable and your car will not tip/roll off them. Mine were under the front cross-member and the rear wheels up on wheel ramps.
2. Remove front interior carpet / underlay, and seat/seats exposing the floor / inspection hatch. Mine had a side mount floor shifter already.
3. Disconnect battery. (You will need to do this for any welding anyhow)
4. Remove starter motor. Total pain in the arse, but get the three bolts out with a lot of messing around. You can see them with the inspection plate off inside the car, but to get to them you need to snake your arms into the right spot and use your sockets to get them off. (took over an hour one mine)
5. Remove speedo cable from dash and gearbox ends.
6. Remove the bolt-in underneath cross member that sits below the box. Just 4 bolts and remove the handbrake bracket at the same time. (Make sure the car is secured so it cannot roll.)
7. Support the rear of the motor with a piece of wood on top of a jack so you can let the rear of the motor down in a controlled fashion when you have removed the gearbox cross-member.
8. Drain gearbox fluids. On FX - EK the drain bolt is in the centre of the cover on the bottom of the gearbox.
9. Remove old tail-shaft by undoing the bolts at the rear end of the car. Make sure not to lose bolts, clips and the needle bearings in the joints.
10. Remove shifter from inside the car. Mine was side mounted floor shifter.
11. Remove the flywheel cover plate and set aside for later. I cleaned and painted mine.
12. Undo the bolts holding the engine and gearbox together, 4 pass through the mounts from the front. The rest are got to from the back (2 through the inspection hatch.
13. Drop gearbox out carefully. Easiest with two people.
14. Remove pressure plate from flywheel, clutch plate will come out now.
15. Remove the flywheel by undoing its bolts to the rear of the crankshaft. Take note of the relationship of the flywheel to the crank and mark this for later. This would be a good time to have it skimmed / machined (Cost $30)
16. Remove Spigot Bush from end of crankshaft. Either use a slide hammer for this (be very careful not to damage the inside of the rear of the crankshaft) or fill the current bush with grease, find a piece of wood (dowel) that just fits inside the current bush and knock it in with small taps of a hammer. This will force the bush out by use of hydraulic pressure. If the bush doesn’t come all the way out on the first attempt, remove the dowel and fill the bush with grease again and have another go. (I used the third alternative with wadded wet paper. Fill and use hammer with correct size rod to force bush out…takes a while)
17. Insert new Spigot Bush into crank being careful to make sure it is square.
18. Remount flywheel (if removed earlier). Assemble new clutch / red motor pressure plate onto flywheel.
19. 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.
20. Assemble bell-housing onto gearbox. I had to purchase new metric bolts (fine thread) for this. Check the size and stock up correct lengths.
21. Drill holes to accept flywheel cover plate. Much easier out of the car.
22. Remove the Celica gearstick and install gearbox to motor using original bolts.
NOTE: At this stage it was obvious (and expected) that the floor and floor support structure would have to modified to allow the much larger Celica gear-box to fit. The box couldn’t be raised to correct position as was. The floor was cut away as little as possible, but the intention was to weld in a new tunnel and build a new solid member above the gearbox as part of the floor and a new cross member / removable mounting plate below the gear-box, using the gear box rear mount. The auto cars have quite a different arrangement for the sub-frames and tunnel. Ideally if this car was being totally rebuilt a new auto floor would have been added.
23. Cut out tunnel / floor to allow gearbox to sit in correct position.
24. Ensure engine / gearbox is sitting in final position. I had it jacked up with axle stands underneath.
25. Insert the Celica yoke into the rear of the gearbox until it gently seats.
26. Measure the distance from the centre of the universal joint cup on the front yoke to the same place at the diff yoke. MAKE SURE YOU HAVE THE WEIGHT OF THE CAR ON THE REAR SUSPENSION AT THIS POINT SO THE REAR WHEELS ARE SITTING AT THEIR NORMAL HEIGHT IN RELATION TO YOUR CAR’S BODY, OR YOUR TAILSHAFT WILL BE TOO LONG/SHORT FOR YOUR CAR! Usually, you deduct 25mm from this measurement to allow for rear axle movement up and down.
27. Take your original tail-shaft and the Celica front bit of tail-shaft to an engineering place and give them the dimension that you measured above. Make sure you tell them if you have or have not taken the 25mm off the measurement already. Have the tail-shaft shortened and the conversion end added, and balanced. Mine was done by a tail-shaft specialist and cost $70 for the shaft and $50 for a new front universal joint (Note: you need to take the bolts / mounting bits from the rear end to the driveline guy so he can use them to mount the shaft in his balancer.)
28. Next I made a new steel strap over the top of the floor in 6mm steel that will clear the box, support the floor and allow a new tunnel to run over the top. My fabricator mate welded this to the cross member/floor. The bottom cross member was to be installed shortly.
29. Install clutch mechanism. I replaced my worn out slave cylinder at this time. Had to trim the mount slightly to get it to fit. Cleaned up the old push shaft / adjuster and reused it.
30. Install new speedo cable (Holden top end/Japanese bottom end). The new cross member will need to miss this. Mine originally ran from the passenger side to the speedo. The new one is shorter and runs from the drivers side up to the speedo.
31. I have no reverse lights, but hook them up now if your car has them.
32. Install flywheel/clutch cover.
33. Now we could assess where the gear box mount sat, and where the handbrake and speedo cable ran. We fabricated two RHS droppers from the original cross member ends to the level of the bottom of the gearbox. These wrapped around both sides of the original cross member stubs and were fully welded on all sides / joins.
*I'll add a photo when I remember to take one! At this stage we were too eager to get the car running!
34. A 8mm plate was fabricated to join these droppers across the car and to reach back to the gear box rear mount. This bolts to the droppers to allow the engine to be removed. These were all painted in Killrust / paint.
35. The gearbox/ engine is now supported in front of the engine at the front x-member, at both sides between the box and engine, and at the rear end of the gearbox. Both sides of the front sub frame are connected top and bottom and the tunnel will be re-welded in after the install is finished.
36. Refit hand brake bracket. Mine is 30mm offset now to miss the new structure. Adjust handbrake.
37. Make sure the drain bolt has been fitted and tightened down.
38. Fill gearbox with new Oil (to the level of the drain plug…usually using a 1 litre gearbox oil container and a length of garden hose).
39. Install starter motor.
40. Trim floor neatly around the shifter location and install gearstick/rubber boot as required. My gearstick was cut off and fabricated from new to rear down low under the front of the bench seat before curving up to the final position. Will get chromed shortly.
41. At this stage bleed your clutch system in the normal way until it feels right and no air is trapped by the system. Mine felt almost the same as it did prior to the swap, with only a slightly firmer feel.
42. Check that you can get all gears.
43. Recheck all nuts/bolts are tightened to the correct torque.
44. Remove car from jack-stands (remember to remove the rear stands first and to have your handbrake on so the car does not roll away while you are removing the stands from the other end! )
45. Reinstall front seat for a test drive………
46. Cross fingers.
47. Take car for test drive. Mine worked perfectly.
48. Then we fabricated a sheet steel tunnel that sits above the new structure.
49. Extra infill (non-structural) pieces were bent up and screwed into place.
50. Two holes were drilled to access the bell-housing to engine bolts, then the inspection cover and new pieces were all coated in fiberglass/filler to fully seal any gaps.
51. Then I re-installed the sound deadener and carpets…and made a shifter ‘boot’ to seal the floor.
52. Re-install interior.
53. DONE !
The Kardinals, Melbourne.