So....I have a s20 a000 that the gears are shredded in. I bought an s40 a000 out of a 2000 civic lx that needed a ISB. When I was tearing it down to replace it, I cracked the transmission housing (Part # 21200-p4a-a00) and im having a bunch of trouble finding a new one. So to keep costs down, I'm wondering if I can use the transmission housing from my shredded s20 and bolt it up to the s40 clutch housing? Any advice is appreciated. My car's a sh!#box so I'm not trying to buy another new transmission.

 

I don't remember which is which between the s20 and s40.... But if they are essentially the same housing (all from the 96-00 era manuals) you can but you will have to do the thrust shim measurement and change the thrust shim for the main shaft in the transmission. If not you will have much worse problems like eating bearings.

The tool to do the measurement isn't available through Honda any more and costs just as much to have one machined as it did to buy from Honda.

 

I see. Thanks for the info

 

If I just replace the s40 housing with another s40 housing will it still need to be reshimmed?

 

Yes. If you simply replaced the ISB in your original transmission cases (and you didn't break it), you would still have to check the preload/free play of the main shaft and shim accordingly if necessary.