From Z32 Gearbox to RB25 Box

[BL4KL15TD]

sooo long story short it's coming up to new gearbox time...

Playing with idea of going RB25det box as from experience its far more superior in regards to comfort, ease of shift and etcetera. Does anyone know what be involved in changing this over from the Z32 set up? Some concerns are if I will need: new clutch, thrust bearing, spigot bush, etc?

[Damo 69]

although if i could be fucked i would google it for you, but there heaps of links, pretty sure castlemain rod shop do the Sr20 to RB25 box conversion. http://powertune.com.au/products/by-brand/powertune/powertune-sr20-rb25-gearbox-adapter-kit.html
lots of guys with CNC machines do SR20 to RB25 box convertions and i am sure they can answer the Q's, and supply the spacer required

[R3N]

Pretty sure he has the z32 box and is contemplating oing br25 box. But why?

[GhostFc3s]

cause the z32 gearbox is a horrible shifting gearbox

[Marti]

Your kidding right ?, a z32 box (if in good condition ) shift fine. Mine did, smooth, no crunching and no missing gears. Not to mention if you've broken a z32 box your doing something wrong. A z32 box is cheaper to replace than a rb25, also I maybe wrong but you will proberbly need a different tail shaft and shift linkage for the 25 box conversion.

[joshg123]

With the gooseneck shifter linkage it makes it a horrible box to drive. If you use one with a unmodified linkage and have the shifter sit down to the left in the passengers thigh spec they are not too bad. but when you use the Alpha omega shifter kit you may aswell be mixing up a brew of soup.

You can shave 10mm off the bellhousing and there is adaptor plates to suit, and use a rb25 bellhousing, but you will then need a s13/14 clutch setup rather than the 15 twinplate you currently have. Shifter sits forward and requires gooseneck shifter.

Dont know if they are availible yet, but GK tech were talking of the cnc bellhousing - again new clutch and flywheel

Or you can get one cut and shut, S13/14 setup must again be used and again the shifter sits forward in the car.

What you have at the moment, is the best 'fitting' version out there. You just need it to work correctly, a rebuilt box with good synchro's is going to be as good as a rb25 box. And a bit of revision on the shifter as i mentioned to you a while back will make it apples again.

It wasnt always that bad, its the shifter linkage falling to bits on that setup giving you grief, and some poop synchro's

[BL4KL15TD]

Damo: what R3N said

Marti: Totally agree Z32 boxes are cheaper to replace and even a cruiser can be poorly driven. Its usually the 2nd - 3rd change is messed up by the DRIVER besides... I've only had it a couple months. In this case it's 3rd to 4th worn synchros, this evidently sufficed when a piece of the gearbox/cog appeared upon the last gearbox fluid change.

Josh: You're response answers it all... I'll definetly bring it through. You're right I remember when I first got it, it was like a virgin.... so loose now.. lol! It still goes into fourth fine but almost always makes a crunch, no matter what I do. A closer look at it will dictate what to do next, will stay Z32 to save some mulla though. cheers for the all the mad advice

[180SXTCY]

gktech not making his adapter kits yet as they need a minimum order of 40, and i think they only had about 25 or so.

rb25 and z32 use the same clutch.

I has a z32 gearbox behind my sr20 using a s15 hks twin plate, and then also put a rb25 gearbox behind it using the same clutch.

[munt]

Gktech are still waiting for a few more people to put their name down for a bellhousing before they cast a few. I put mine down a few months ago and they still needed another 10 people.