Upgrades:KE70 K50 gearbox into 3K powered KE20

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Putting a KE70 5 speed K-50 Gearbox in a KE20 (in the place of a 4spd)

After finding that 4 gears are just not enough for me and then just happening to find a good deal on a 5 speed gearbox that I couldn't pass up I went ahead with the conversion.

At first glance you would think that it would be a 2 hour job. Well its a tad more. We worked for 3 hrs to get the old gearbox off (2 of us and mind you the gearbox hadn't been taken off for nye on 30 years ORIGINAL CLUTCH!!) and then found that a bearing we needed had exploded/died and wasn't easy to source (N.B. 2007 these are now easy to find!). Grimwolge came to my rescue with exactly the bearing I needed. If you're using the 3K I would suggest you use a flywheel off a KE70 4K. It will give you a wide range of easily accessible clutch upgrade options and they're lighter! I am unsure as to weather the 3K flywheel and clutch would work as I never tried. Update: I since changed back to the K40 because the K50 blew its seals out and I couldn't find a replacement. The 3K K40 fits fine with the 4K clutch and flywheel! You could reasonably assume that the K50 should fit the standard 3K flywheel and clutch.


The old on the left new on the right (Bottom to Bottom). Note the shifter position difference!

The shifter difference isn't a huge problem. There is a viewing plate that can be hack sawed out back a fair way. I actually think that the shifter in the further back position and a shorter shifter is actually a big improvement. Now I don't have to reach to change gears! When I can find an aluminum plate I'll drill it over the old shifter position, screw it into place and then use silastic to seal it. Because the cross member is there, there shouldn't be any stress put on that part of the car.


Several things need to be modified to fit the new gearbox. The bolt holes in the cross member need to be redrilled further apart. You may want to try a KE70 cross member as a better option however I don't know if it is the same width. Worth a try.



One of the bigger problems is bolts. The left hand side base bolt needs to be longer and a pin below and further above the starter motor (^^red circles^^) exists on the KE70 gearbox but not the 3K motor. This may just be a 3K-4K thing. Also I didn't notice until we had the gearbox on the engine ready for bolting up that one of the bolts on the right hand side (when looking at the box from the back) doesn't quite match up. Its OK though as there are enough of the other bolts to hold it there. If you did the 4K conversion then there wouldn't be any bolt problems! (next on my list)


Reversing lights are significantly different. Wiring can be done however you like. We just used 2 crimp terminal connectors and plugged them in (making sure they didn't make contact). Of course you could go and get the proper connector for this...but Im just lazy! One of the green connectors (I think the top one) is the neutral light but Im not exactly sure what the other one is. We were thinking it may be the 5th gear light...but Im not sure why you'd bother with that!


Take to it with the hacksaw....then....



We found that the viewing plate has to be cut all the way back...and then to do a good job you have to widen the hole a bit more towards the rear. This is because if you just cut the viewing plate out then when you start the car, reverse etc the gearbox rotates slightly and knocks against the side of the hole. You could of course just chuck a heap of rubber around the rear of the shifter hole and stop it that way.

I'd Like to take this opportunity to thank my father. Didn't really agree with me doing this conversion but he was happy to help me anyway. THANKS DAD :) And as you can see its his arm/leg/whatever in most of the photos...so he did all the hard stuff. Id also like to thank Grimwolge for letting me take this gearbox away and put it in, try it out and didn't ask for a cent till I was happy with it!

Article by Irokin (2003) - contact him at [email protected] (remove hates spam of course).

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