RB25 conversion Stage 13 - Installing the gearbox and modifying the speedo sender

The speedo sender on the R33 gearbox is electric, and the R32 uses a mechanical speedo cable. In order to get around this problem, you can use the speedo sender from a Nissan Navara and modify it. Here are the 2 speedo senders (Navara on the left, R33 on the right)...

To remove the R33 gear simply undo the circlip holding it in place at the top. I used a couple of picks to pull it off...





Now to get the gear off the Navara speedo sender. This is more tricky as it's pretty well stuck on. You'll need a dremel or similar and cut the plastic in several places until you can peel all the plastic off the metal shaft...




The R33 gear is slightly too small to fit straight over the Navara drive, so I used a 10mm drill bit to remove a (very) tiny bit of plastic. This made the gear a tight fit (I had to use a rubber mallet to get the gear on). I used some glue just to make sure the gear wasn't going to come off by accident.




There's a bolt hole in the gearbox that held the old speedo sender in. You can cut a groove in the speedo sender then use a piece of metal bolted in this position to hold the speedo sender in place. Unfortunately my bolt sheared when I was removing the old speedo sender, so I removed a bolt in the bell-housing the side of the gearbox where the speedo sender already has a groove cut, and I made up a small bracket that I could bolt in place and would hold the speedo sender in place.





On to installing the gearbox. With the help of a mate I bolted the gearbox to the engine to see how far out the bolt holes for the transmission mount would be. Turns out the mount holes need to be moved towards the front of the car by about 40-45mm. A quick call to my mate John and he modified the R33 gearbox mount to locate the holes in the correct place. This worked a treat, but the gearbox was a bit too close to the floorpan for my liking, so he made me a couple of spacer plates to level the gearbox out nicely. As you can see from the pics, the speedo cable is a bit too long. I could get this shortened, but I'm going to secure it to the chassis and leave it the length it is for the time being as there are no really sharp kinks so it should be fine.