s14: CD009 Conversion

Around the start of 2022 I broke 3rd gear in the s14 at Skidpan.

Playing too much assetto corsa over the covid lockdowns eroded any sense of mechanical sympathy I used to have when I decided to lazily repeatedly clutch kick 3rd at super low speed at Skidpan before hearing a shattering sound and gaining an extra neutral.

I spent awhile researching and pricing up different options. By this point any second hand rb25 gearboxes to be found weren't far off the price of new and this was already my second box at this point. A few of my friends have gone the CD009 route via different conversion methods and after much discussion I decided to go ahead with it using a Mazworx bellhousing.

After a bit of shopping around I ended up ordering the box through Streeter which arrived at my door pretty quickly and was much cheaper than sourcing locally even at trade price.

If you're looking at CD boxes keep in mind the first gen you may find cheaper but they can be prone to Synchro issues. You want the revised version which is aka CD009/CD00A. You can also use the box from the 370z which I believe starts with a JK but check with your conversion method as you may require extra parts due to them using a hydraulic clutch release bearing.

Anyways time to get cracking on the conversion. First task was to drop the blown box which wasn't too bad from memory. That said RB box with a studded adapter plate like what I had is a giant pain to refit even on a hoist with multiple people.

The Nismo twin plate I recent swapped in was still looking fresh. I used to run a NPC 10" HD Organic clutch which must've allowed enough slip to save the box from my stupid driving for a few years as I blew 3rd on my first outing with this clutch.

I removed the pilot bush too which I highly recommend purchasing a proper removal tool as it makes removal a breeze. No messing around with grease, bread or other internet methods that make a mess or don't work.

This is where it got really fun... I managed to remove half the bolts for the adapter plate but the rest were absolutely seized in there.

The allen holes were rounding and I was getting frustrated.

I got frustrated and left the car for a few days feeling defeated. One day I regained some motivation and had the idea to attack the problem with the power of glueing metal together. I must say my tig machine has paid itself off in many ways over the years.

I couldn't believe my eyes as I went to loosen the bolt and it was turning! I think the heat from welding helped to break any galvanic corrosion seizing the dissimilar metals together.

After cutting the sacrifical impact driver and repeating the process a few more times I finally got the damn plate off. I really hated adapter plates even more after this experience.

Time to start getting the CD box on. Mazworx offer a pilot bearing install tool which is meant to set it at the correct depth for their conversion.

The next part was the hardest part. Hacking off the bellhousing of a brand new gearbox... I used a combination of sawzall and hacksaw to get this done.

Probably learn in 10-20 years that the front bellhousing of CD's are become sought after like the auto JZX transmission I binned.

By this point the part where you cut the input shaft down doesn't hurt as much.

I went to unbolt the front cover and quickly learnt the hard way that there was still oil in the box I presumed was empty from factory.

Mazworx conversion bellhousing and GK Tech shifter on.

Clutch fork assembled. It uses a SR fork, pivot and carrier as it's designed to be the same dimensions as the SR bellhousing.

Nice little badge that'll never be seen again once it's in.

Sitting ready for installation another day.

My tailshaft was made with a yoke to suit 1350 joints and the rest of it 1350 hardy spicer joints. I believe the tailshaft is 3.5" which is a thick boi. My RB conversion tailshaft on the left for comparison.

Adam came over to help me get the new box in. For mounting it's using the GK Tech conversion crossmember along with the Nismo gearbox mount off my blown RB box. It was a bit tight to get in but we managed after a few tries. Much easier than my previous encounters removing/refitting rb boxes with the adapter plate.

Since the CD box doesn't have a speed sensor in it, I used a Dakota to convert my rear ABS sensor into a signal for the cluster.

I filled the box with oil and fired up the car to test rowing through the gears. Success! Well at least on the jackstands.
I took it for a test drive and damn was it nice to have a fresh gearbox again in this car.

In hindsight I sort of wish I didn't overbuild the car requiring such a gearbox/conversion. HPI 6spd seems like a good option for lower power while bolting straight in or even better I should've kept the car simple with pump 98, t28 and a stock box.

Ahh to have a time machine...