This post will be continuing on from the previous post about the FS5W71C / RB gearbox conversion which can be seen HERE, and I will also be going through a quick guide of how to change basic maintenance items on an L28 motor. The change in seals, etc, should be the same for the L24 and L26 motors.
Okay, so continuing from where I had left off, to check and see whether your modifications performed on your bell housing is correct, you will need to try and spin the input/output shaft and shift into each gear. If the input/output shaft doesn’t spin, you have an issue or if you can’t shift into any gears, you’ve got an issue. I had those above issues lol I must have bumped a shifter rod and the box felt like it had seized.
If you’re in the same position, you will have to follow the below procedure. First, open your shifter cover and while using a punch, tap the pin down and out.
Once the pin is removed, slide the ‘unknown named’ piece off.
Once that piece is off, you can take the back half of the gearbox off. No other bolts needed to be removed.
If you can’t select any gears, you need to make sure the rods are all lined up. One of my rods, I believe 5th and reverse, were pushed back and so therefore jammed everything else up. Knocking it back into position, I was able to rotate the shaft and select gears again.
Having it in this position, you are in neutral.
If you are mechanically minded, I think you will be able to understand how the gearbox gets into gear, etc. Having never pulled a gearbox apart before, I sure learnt a bit from this small exercise.
Once you’ve knocked the rods back into position, you should be able to put everything back together or make further modifications to your bell housing and making sure everything moves freely.
Only requirement now is to modify the gearbox cross member and cut the dust shield off the tail shaft which will be illustrated in a moment. For now, I wanted to pull the motor out to freshen up a few areas which needed attention.
Just want to say thanks to Tony for lending his brand new engine crane to me and lending a hand! Cheers.
Motor’s all out.
Keeping in mind that I pulled everything out, changed gearboxes because I needed to change a clutch, and what better time to do everything while it’s out… I ended up ordering an Exedy Heavy Duty item.
There are different clutch kits which fit the Z and it is important that the clutch diameter matches your flywheel, and that the pressure plate height remains consistent otherwise you will need a new throw out bearing carrier also.
The clutch kit came with a new clutch, pressure plate, spigot bush, alignment tool and throw out bearing.
Back to the motor, I first pulled things not needed out of the way and gave it a light scrub.
The goal here was to give the motor a fresh lick of paint, change the water pump, welch or better known as freeze plugs and front/rear main seals. I had bought the water pump a while back but never got around to installing it as the previous one never gave me any issues.
New water pump, bolts, front and rear main seals, and welch plugs. The welch plugs, ten are 35mm and 1 is 50mm.
First up, the water pump. Simply unbolt and take off.
Installation of the new item should be a straight forward bolt on. I threw out the gasket and just used a gasket maker which I’ve had better success with.
Next up are the welch/freeze plugs. I have given the block a few coats of Ford blue.
To remove the welch plugs, simply use a chisel or screw driver and a hammer, knock one side of the plug until it falls into the block.
Use a pair of pliers then pull it out. As you can see, they’re already corroding. Better to replace them now than to wait for them to rust through and leak.
Repeat another 10 times. To install the new plugs, get the largest socket you can fit into the new welch plugs, and hammer them into the block. Simple as that! It is recommended that you sand the hole down a bit so that the new welch plugs don’t leak or pop out.
Moving onto the rear main seal.. The best way to remove these I have found is to get a self tapping screw, a drill bit to suit and drill into the seal, making sure you don’t scratch any surface of the crank or block.
Screw the self tapping screw into your new hole.
And using pliers, pull the seal out.
To re-install the new seal, find something of similar diameter, I found a pot which broke after a few taps lol
Place new seal over your crank with a bit of engine oil to lubricate it.
And then use your pot or something similar in diameter to knock it in evenly. You can use your old seal, placed on backwards, to help push the new seal in. Tap it in until it sits flush.
Now, the front main seal. Your first step is to remove the crank bolt, it is 27mm. You can stop the crank from spinning by installing two old fly wheel bolts on the crank at opposite ends, and put a pole in between them and wedge it on the floor.
I re-installed the bolt without the washer.
You will need a puller to take the pulley off.
This little thing was leaking oil all over ever since I got the car. I’m happy to be changing it!
For the front main seal, I just pried this one out with a screw driver.
To install the new seal, same thing as the rear main seal, find something of similar diameter and tap it in evenly.
Here’s a poor photo of the motor with the pulley and water pump back on.
The following day’s work was to put the motor back into the car, here’s a picture of the accessories back on the motor. Ignore how I’ve lifted the motor, I didn’t trust the manifold bolts.
Time to put the flywheel back on. I bought brand new ARP bolts, they’re the same thread and pitch as those used on 3SGE Toyota motors or RB Nissan motors.
Don’t forget to place your backing plate on first before installing your flywheel.
Using some locktite, torque them up to spec.
Next up, install your new spigot bush.
Grease it up a little bit, find a socket of similar diameter and knock it in gently.
You are now ready to install your clutch and pressure plate. Don’t forget to wipe down the surface of your newly machined flywheel with brake cleaner. They’ve sprayed something on it to reduce corrosion and leaving it on will result in slippage and shudder.
Remember that the fatter end of the clutch faces the pressure plate. See below.
So what you do is place the clutch in between the pressure plate and flywheel, lightly tighten up the pressure plate to hold it in place. Once it’s held in position, before you torque it all up, insert your alignment tool. Make sure it sits snug and tight.
You’re ready to torque up the pressure plate bolts. Tightening them in a crisscross direction to avoid uneven pressure on the clutch.
Take out the alignment tool and this end is ready!
Before you can bolt your gearbox up, you will need to change the throw out bearing. To do so, you will need a socket of similar diameter to the bearing carrier and a few planks of wood.
Rest the bearing on the planks of wood and knock the bearing carrier out of the bearing. Install the new bearing by knocking the carrier into the bearing. Pretty straight forward.
Give the carrier a light grease and install it with the clutch fork in the bell housing.
And then bolt your new gearbox onto the motor.
The motor was then put back into the car as one. Had a few issues, engine crane didn’t clear the car underneath, length of the crane was a tad too short which meant taking the motor and box which was halfway in engine bay back out, resulting in scratches etc..
But the motor ended up going in.
Now onto the final part of this gearbox conversion! Finally..
As you can see, the gearbox cross member needs to be modified. The mount on the gearbox sits about 25mm further back compared to the original box.
What I did was section an area of the cross member and shifted it back 23mm from memory and welded it in place. Looks a bit dodgy with the wet paint in the pictures, but it was pretty solid.
I installed the cross member and realised the bolt to tighten the gearbox mount bolt wasn’t accessible, so I had to remove a bit of metal.
I have seen people completely remake their cross member but I don’t have the skills for that lol This will do..
Install it and it should all fit!
The last part to this conversion is the tail shaft. Simply remove the dust shield on the end which goes into the gearbox.
I only removed 10mm to clear the diff mount but I soon realised this wasn’t enough, take my advice, remove the entire cover!
And you’re done… I still need to paint that airbox and polish the cam cover though..
With the RB gearbox, although you don’t need to shorten the tail shaft, your shifter does sit further forward. The below photo is of the shifter in neutral.. It looks like it’s in first or third! Your hand might hit the climate control, you can cut and shut the shifter to reposition it or bend it.. I haven’t decided what to do yet.
My speedo cable plugged right in, so did reverse switch BUT.. The reverse lights stay on the entire time.
I had read that 5 speed boxes don’t require any modifications to the reverse switch on the bell housing, only the 4 speeds do, but I ran into this issue of it staying on. I should have double checked myself, but I can say that 5 speed gearbox will require you to move the switch location forward 25mm or so. I will have to pull the gearbox back out and apart to fix this :(
Other than that, the gearbox has been good. I just need to run in the clutch. There are heaps of articles and documentations on this conversion but if there’s any questions, feel free to ask.