S53 Gearbox stripdown The optimist voice in my head said "open the spare S53 and see if it's an easy fix" The other rational voice said "forget it - that kid fukd it good!" The box was good apart from the fact it refused to stay in 1st or 2nd gear, those 2 gears share an actuator so I was being optimistic. Usually it's 2nd, then 1st that goes due to the amount of torque those gears have to transmit. Removing the outer cover I could aready see the box had been re-furbed before How do you fuk a box TWICE in less than 140 000km??? Outer casings & 5th gear removed The gears and linkages complete minus 5th gear The gears with linkages removed, note reverse gear idler seperate on it's own shaft The gears from the other side, reverse idler gear removed to show the shafts Bottom small gear is 1st, straight cut gear is reverse (that's why it whines in reverse, race boxes are also straight cut), then 2nd, 3rd, 4th above. 5th sits outside the main casing on those splines at the top and easily changed without opening the box. (6 speed conversions lenghten those shafts and add another gear outside the 5th gear, using the 5th gear selector to work in 2 directions) The gear linkages, note they are covered in nylon for better wear, noise etc. C-Series boxes do not have the nylon covers, there are NO interchangable parts in the C-Series The gears and diff removed, the diff is matched to the secondary shaft - ie. you cannot change the diff ratio without changing the secondary shaft as well. The gears are pressed onto the shaft apart from 1st, R, 2nd which are machined as part of the primary shaft. Changing diffs/ratios/shafts is not as simple as you would think! The inner casing (bellhousing) with it's large roller bearings, can be swapped with MR2 or FE type bellhousing Unfortunately all the syncros (incl 5th & reverse) were totally fukd due to hooligan antics, so some parts have gone into the spares collection, the rest are in the bin. BE WARNED - Short shifters & crash changes! These gearboxes use brass rings to "brake"/slow the spinning gears before the teeth can mesh (similar idea to your handbrake shoes) If the gears don't have enough time to slow down due to short shifters or crash changing, thin oil, oil additives etc The syncro teeth are ground away by the motor, resulting in a box which struggles to select gears, won't stay in gear etc, and the gears then look like this... I also recommed using 80W/90 Gear oil, ATF is designed for Auto boxes and does not protect your gears and bearings as well as gear oil, esp if you are prone to ramming it into gear. (Auto boxes use hydralics or magnets to keep it in gear and have an oil cooler to keep temps down!) ATF is great for race gearboxes which are overhauled regulary, not in a 22yr old worn box. My box turned out to be a std JDM item, gear ratio's are as follows: 1st - 14/46 = 3,286 2nd - 24/49 = 2,041 3rd - 31/41 = 1,323 4th - 35/36 = 1,028 5th - 39/32 = 0.820 Diff - 17/71 = 4,176 Which is actually very disappionting, the JDM car is set for very fast acceleration with very little top speed ie: (a 1500cc Alfasud has longer gearing and higher top end!!!), it will be difficult to get more than 210km/h out of these ratios. Great for track/rally use but totally useless for economy in highway use. I'm now looking for a 5th gear set 0.731 or lower ratio to suit these boxes? Anybody got a busted box? Anybody got a busted box in N.Z with a 3.9 or 3.6 diff? What seals are interchangable between the boxes? Easy filling Tip I found an easier way to fill these boxes. Remove the filler plug and the reverse switch on the top. Put a small funnel into the switch hole and fill till oil runs from the filler hole - easy!