A while back, my 1990 Q45 stopped shifting into anything but second, neutral, or reverse. Not having any free time with due to school, I continued to drive my car. Even with sparing use, it took its toll on the transmission and I finally had time to take it to the shop three weeks ago. After they quoted me a minimum of $2300 minimum to rebuild the transmission, I decided that swapping in a 5 speed was the only choice.
Two weeks ago, I woke up one morning and figured I'd check Craigslist for a potential Z32 parts car. Of the two results, one was a 2+2 with a manual and the guy was only asking $125 for it! After about an hour drive and for $260, I had the following:
- transmission
- clutch disk
- pressure plate
- flywheel
- shifter
- throwout bearing
- clutch fork
- hard lines
- master and slave cylinders
I ordered the Kisuu adapter plate for Performance VH (Mazworks clone). Once I had it in hand, I took it to the school machine shop and removed the thickness of the plate from the bellhousing. This is when some of this plate's shortcomings became apparent. The plate uses different dowel pin holes from the Z32 transmission and requires new holes to be drilled. I was told to bolt it up and use the plate as guide.
In reality, this defeats the purpose of using dowel pins as they locate the input shaft of the transmission with respect to the flywheel. I had to drill holes through the back of the adapter plate and pressed the dowel pins to get them out. In an attempt to maintain the alignment, I turned two pins that fit into the machined holes on the transmission and the threads of the adapter plate with about 0.001" of play. I made another pin to fit the plate's dowel pin holes and used it to align mill spindle. This should produce the best alignment possible.
In between doing some work on a UTV at my buddy's place, I have been able to make some good progress on the rest of the swap. I mentioned to his dad that a Frontier should have a slip yoke that fits the Z32 tranny and I scored big. He happened to have a junk first gen Frontier than he had no plans for. We used a Bobcat to drag it close enough to the garage to use air tools and flipped it onto its side. After some work with the impact and sawzall, I had not only a driveshaft (which fits both the transmission and the differential, but needs to be a bit longer), but also a clutch pedal, brake pedal, and 6 flywheel bolts.
At this point, one of the main components I was missing was a 300zx starter. I was also a bit apprehensive hacking away at the block. We decided it would be best to use the stock starter, but the ring gear didn't align properly and the chamfers on it were on the wrong side. Our solution to this was to turn an 1/8" off the flywheel and use the Q45 ring gear. A torch took the 300zx ring off and a grinder took the ring off the Q45 flex plate.
After we got back from our friend's shop with the newly machined flywheel, we popped it in the freezer and dropped the Q45 ring gear in the coals of a fire that had been burning earlier. It's worth noting that the face that is already machined on the flywheel needs an 1/8" removed and the area around it needs 1/16" removed for clearance. After 10 or 15 minutes in the fire, the ring was expanded enough to easily drop onto the flywheel. We used 1/8" TIG wire to space it out from being fully seated on the flywheel and a brake rotor to keep it pressed on. This yields a total displacement from stock of 1/4" and perfect alignment with the stock starter. A 1/16" or less hangs off the edge of the flywheel. There are no issues with clearance with the block.
The flywheel cooled quickly and we removed the wire, which was probably the hardest part. We bolted it to the flywheel with 4 of the Frontier flywheel bolts and 4 VAG triple square bolts we found with the same length of thread. The adapter needed a bit cut off to allow clearance for the starter, losing one threaded hole in the process. The transmission also needed some material removed.
After trying to use grease to remove the automatic pilot bushing, we got my friend's dad to weld a bead around the inside, which allowed for easy removal by hand. The 300zx pilot bushing from Autozone tapped right in. We bolted up the adapter plate and pressure plate next. We didn't use an alignment tool for the clutch plate, but it wasn't hard to get it concentric by eye. At this point, we also put the bellhousing back on the transmission.
So, what's left to to do?
- Make a new driveshaft that's the right length
- Bolt in the transmission
- Get the shifter inside the car and centered in the console
- Figure out the pedal situation
- Figure out how to connect the master and slave cylinders
- Wiring
- Speedo correction
- Make a shift boot/gate and knob
- FIX THAT DAMN TICKING NOISE!