Overview

The H55F Transmission swap has become an increasingly popular modification lately, now that they are readily available in the US and are very simple to install, especially on post 4/85 FJ60s. It's basically a bolt on modification, which I know everyone loves. There are benefits on both sides of the speed range, with a lower 1st gear for a small crawling improvement and a higher (or existent) 5th gear for highway cruising, the reason I decided to purchase mine. Ever on the interstate in 4th gear and try to shift into the non-existent 5th? I decided I wanted to make that dream a reality.

H55F vs. H42 Gear Ratios

	1ST	2ND	3RD	4TH	5TH	R
H55F	4.84	2.61	1.51	1.00	0.84	4.84
H42	3.55	2.29	1.41	1.00	--	4.72

I assume it saves a little gas, but for the almost $2000 price tag, I wanted it more for preventing engine wear and general comfort. Now I'll be able to cruise down the interstate at 75MPH with the engine spinning at 2750 rpm instead of 3250. It'll make my road trips a little less noisy, save a little gas, and keep the engine alive a little longer. Plus the toughest job I've ever taken on was fixing the parking brake on my 1967 FJ40, so I thought it would be fun and educational, and at the same time I can replace all of the clutch and driveline parts that have been going strong for 200,000 miles.

In 1983 the H55F was installed in just about every vehicle except those destined for the US. Why? Well I think Toyota thought the luxurious US market wanted a more refined feel, and the H55F is a little more work to shift through its 5 gears instead of the H42's 4. Plus the speed limit was still 55 here and the H42 was an okay transmission for this speed. But fortunately for us swappers, in April 1985, Toyota decided to make the H55F and the H42 the same size to keep the driveline the same, extending the front driveshaft, eliminating the need for a Carden Joint, and shortening the rear. This meant that the H42 had a spacer added to the rear of it where the 5th gear was in the H55F. So now no modifications were needed to fit the H55F in an H42 equipped FJ60. Good deal! I also really wanted to keep Toyota parts in there without modification, since my goal is to be able to travel the world and the low skilled labor and lack of parts in remote locations will be all I will have to work with. But the H55F and the FJ60 are familiar sights and will be easily maintained. But beware as you look for a used H55F, the input splines on a B-Diesel engine are different from the H-Diesel and 2F-Petrol. Also, some transfer cases that were originally mated to the H55F had a 1.0 high and 1.959 low, but mating it to your 4 speed transfer case with a 1.0 high and 2.276 low will produce a little better performance off road. One advantage of using your stock transfer case instead of an entire H55F-Transfer Case assembly.

While your truck is on jackstands, there are many other maintenance items you can do. Look at your owner's manual to get some ideas of things that need to be done at long intervals, so you won't have to worry about it for a long while. I don't know if my differential oil has ever been changed, so I did that, along with lubing the chassis and checking the brakes and wheel bearings.

DISCLAIMER: I don't really know what I'm talking about in any of this article. Don't trust anything I say. Thank you.

 

Parts List
There were many parts replaced during this swap, some needed to, and some I just wanted to replace to give me piece of mind. These are listed below, along with some pictures:

Transmission-Transfer Case Gasket
Since the H42 transmission had a spacer instead of a 5th gear, it also had a crossbar for reinforcement, causing a lot of bad things to happen, at least for people wishing for a swap. This crossbar has a bolt to secure it, and the H55F has no place for the bolt to be threaded into, so we must plug this crossbar hole to prevent oil from being transferred between the transmission to the transfer case. That is explained later. As for the gasket, you can either get a H55F unique gasket with no crossbar, or get a H42 gasket and cut the crossbar part off.

Note the highlighted crossbar on the old H42	And lack of one on the new H55F due to the 5th gear

 

Split Transfer Case Gasket
Since this gasket will probably be old, it'll most likely crumble when taken off, and even if it doesn't, should be replaced anyway.

PTO Cover Gasket
Since the PTO cover must be removed to split the case, the gasket should be replaced.

Transmission Output Cover Gasket

Idler Gear O-Rings

Transmission Output Nut
Since on this nut you have to bend the sides in to lock it, it is a non-reusable part after you bend them back out. This nut also requires a large 36mm socket.

Transfer Case Output Nut
Since on this nut you also have to bend the sides in to lock it, it is a non-reusable part after you bend them back out. This nut also requires a special socket, this one is 32mm.

Flywheel resurfaced
Since your flywheel has already been removed, you might as well spend the $30 to get it resurfaced. If it was like mine and had never been looked at in 200,000 miles, it would have had some slight imperfections, but they were easily erased and made the flywheel look like new.

Clutch Disc
Since the clutch disc is coated with a material like your brake pads, obviously it was designed to wear out. So this is the part that makes the most sense to replace if nothing else.

Pressure Plate
The pressure plate doesn't necessarily need to be replaced, but with each press on the clutch pedal the spring fingers are flexed and get a little weaker, plus the plate itself is similar to the flywheel in that it probably warps and gets hot spots after time. So might as well replace the pressure plate too.

Pilot Bearing
The purpose of the pilot bearing is to hold the front of the input shaft of the transmission (the nub on the front of the input shaft without any splines fits right in). Again this isn't really important to replace if it still works okay, but give it a spin and if it's not silky smooth it would be nice to replace. It comes with most clutch kits anyway.

Throw Out Bearing
The throw out bearing pushes on the fingers of the pressure plate and in doing so pushes the plate away from the clutch disc disengaging the clutch. This is also included in most clutch kits and so after this swap you won't have to worry about it.

Rear Main Seal
Obviously you have to have something to keep the oil in the engine, and the rear main seal makes sure none gets out from the crankshaft hole. If, when you take off the bottom clutch cover, the whole thing is full of nasty oil that is the dirtiest stuff in the world, this seal is bad and needs replaced. Since it's not included in any clutch kits that I know of, if the seal is perfect then I wouldn't mess with it. But if you have any question, it might as well be replaced.

 

Special Tools List
Even with an extensive tools inventory, there were a couple of odd tools that had to be bought, or for me, made. These are:

Clutch Alignment Tool
Without a clutch alignment tool, putting the clutch back on is nearly impossible. Fortunately, most clutch kits include a small plastic alignment tool that is priceless. You could also use a cut off transmission input shaft, but I doubt most people have that resource.

32mm Socket
This socket is used for getting the transmission output shaft nut on/off.

36mm Socket
This socket is used for getting the transfer case output flange nut on/off. Nothing else will fit but a socket so this tool cannot be substituted.

Metal Pipe
A metal pipe that fits over a ratchet is very helpful to get a little more moment those stuck bolts. I wouldn't trade mine for an entire new toolbox.

Socket Knuckles
These came in handy all the time, but especially when taking off the bellhousing. Those are some long nuts that are just not loose enough to hand-loosen but using a straight ratchet gives only about 10? of throw. Twist it a little with these knuckles and you get a good 180?.

Transmission Jack
You have to use something to get that tranny out and the new one in, and I used a normal floor jack with a wood cradle. Just something to think about before you start.

 

Other required items
There are also a few things you need to think about before you attempt this swap like:

Shift Knob
My H55F from Cruiserparts.net didn't include a new shifter, just a bushing so I can reuse my old shifter. But this means I'd have to get a new 5 Speed shifter knob. If you're in the same boat as me you can get one of these from a 5 Speed Celica in a junkyard for cheap.

Oiler Nipple
This is critical to the correct operation of the 5th gear of the H55F, since the oiler nipple jets oil into the center of the gear. Make sure you have one of these. My H55F included one, I just had to snap it into its hole.

The plug bolt cut off is highlighted, while you can see the oiler nipple snapped in place.

Tap/Bolt
As discussed earlier, there is no crossbar on the H55F, but a hole in the transfer case for one. Without it plugged the oil could be thrown between the two, which could be bad. Might as well not worry about it and just tap it with any tap you want that fits and insert a bolt with some thread locker.

 

Procedure
I have tried to be as specific and detailed as possible, but as you can assume, every project will differ in some way. I thought it was a fairly simple project, but brute strength is needed in a few steps, in which you may need some friends.

TRANSMISSION/TRANSFER CASE REMOVAL

Clean the Undercarriage
No one likes getting 25 year old dirt in your eye, so the first thing I did was drive my truck to a power washing station and power wash the entire undercarriage as best as I could, preferably with the skid plate off. This makes it a little more bearable and tidy under your vehicle while you work.

Disconnect Battery
Just as a safety precaution, disconnect your battery before any type of work on your vehicle.

Remove Shift Boot
Unscrew the shift knob and then take off the four bolts holding the shift boot on and remove it.

Remove Shift Lever
Press downward on the shift lever retaining ring and rotate it counterclockwise to remove. Now the shift lever can be completely pulled out.

Raise Vehicle
I jacked mine up at the differentials and set my jack stands under the U-Bolts. Make sure you get plenty of height, since you'll be crawling in and out of there a lot. And take the tires off too, just to get that much more space under there.

Take the Skid Plate Off
If you didn't take my advice on cleaning the underside, you still have to take the skid plate off, obviously, to get to the good stuff.

Drain Transmission and Transfer Case
You can take the used oil to an auto parts store for recycling.

Remove the Driveshafts
Be sure to mark the driveshaft flanges so they can be installed exactly the same, preserving their dynamic balance. Take off the 4 bolts off on each transfer case output flange and remove both driveshafts.

Remove All Electrical Connectors and Speedometer Cable
Make sure you remember where they all are routed also. The 4WD indicator switch is routed through a series of clips on the transmission and transfer case. Also, on the lead coming from the transmission, a couple inches up, there is a quick disconnect. Go ahead and disconnect it there, since the new transmission has its own new reverse switch that plugs into it.

Remove the Starter Motor
Since you're going to need to remove the flywheel and bellhousing, you have to remove the starter motor. Detach the starter electrical connections, which should be just a large wire and a ground. Remove the 2 bolts holding it in place, and go ahead and take it out.

Remove Clutch Slave Cylinder
It is called a slave cylinder or release cylinder, but either way it has to go. Since the hydraulic hose coming to it cannot swivel, you must take the 2 bolts off the cylinder itself and remove it from the bellhousing before trying to take the hose off. And after that don't step on the clutch.

Detach The Transfer Case Shift Lever
This is a pain since you really don't know which bolts to take off to get the shift lever off. First take the knob off and take the shift limiter bracket off:

 

 

 

Then after that you can take off the bolt for the 4WD shift lever.

After this the lever should just slide off its small axle.

Support the Engine
I had two jacks so I just used the smaller one to support my engine. Make sure you put a block of wood between the pan and the jack, though, to spread out the load. The oil pick up inlet is very close to the bottom of the pan so if it's bent in any way the engine could be oil starved. The engine must be supported any time the transmission is out of the vehicle.

Support the Transmission
I put 4 blocks of wood in a sideways "H" pattern with the middle of the "H" built up with the extra piece (you can see one of the blocks in the above picture). I was pretty successful in removing the transmission with this setup, but it would probably be a little easier to use a special transmission jack. Your call though.

Remove the Crossmember
First, take off the bolts securing the transmission to the crossmember, then raise the transmission a couple of centimeters and take off the crossmember to frame rail bolts, and remove the crossmember.

The transmission mounting bolts after the transmission had been removed.

Remove the Transmission and Transfer Case
There are four bolts securing the transmission to the bellhousing, with an exhaust bracket on the driver's side. Two are difficult to get to on the top and the other 2 are fairly easy on the sides. Here's where the breaker bar and/or metal pipe comes in handy, along with the knuckle.

After these bolts are out, the transmission can be shifted back while holding it steady and straight. A rubber mallet can be used to break any sticks that may occur. Now the clutch components can be replaced and the transmission swapped.

CLUTCH COMPONENTS REPLACEMENT

Remove Bellhousing Pan
The bellhousing pan can be removed after removing the 7 bolts keeping it on. Mine was full of oil and gunk, meaning the rear main seal was bad.

Remove Throw Out Arm
This is just sitting in there, so move it around a little bit and it'll come right out.

Remove Pressure Plate/Clutch Disc
Insert the priceless clutch alignment tool, and begin loosening the bolts holding the pressure plate to the flywheel. Since the bellhousing cannot be removed yet, you'll just have to turn the flywheel by hand loosening the bolts as you go until they're all out. Then the pressure plate will come off, along with the clutch disc.

Remove Flywheel
There are six obvious bolts that can be easily removed with a socket and breaker bar. Use a big screwdriver stuck in the gear teeth to keep the thing from spinning. Then remove the flywheel and get it resurfaced, even if it looks okay. The $30 is worth the piece of mind to me.

Remove Pilot Bearing

This was the toughest thing I had to do. I heard of packing the area behind the bearing with grease and pounding the clutch alignment tool forcing the bearing out. But I was destroying my tool so I decided to take a different route. Someone at the local auto parts store told me just to chisel the thing out, but after beating the crap out of my bearing it wasn't going to work. I read something about using a tap to tap the hole and keep spinning it until it popped out but I destroyed it way too much to be able to do this. Plus the thing wouldn't stop spinning for me to get the tap in. my last resort was to use a specially precision designed tool to get the stupid bearing out. What I did was buy a 3"x1/2" bolt with a washer and nut and grinded the head off all sides but one.

The head is inserted into the bearing and a bracket inserted in the open side to keep the bolt from moving and bent back flush with the crankshaft. From here I stacked some big sockets that are bigger than the bearing that sit on the crankshaft and inserted the nut and started cranking. After a couple turns the bearing FINALLY popped out after a whole day of trying.

	Really beat the crap out of that old bearing.

Remove Rear Main Seal
This is easily taken out with a screwdriver.

So now is our halfway point. This is the most your vehicle will be disassembled for this project. Take a breather and admire how much destruction you have caused to your truck. Take a few pictures and impress your friends! Here's how mine looked:

Sure hope we can get it put back together? Well now we can work on swapping transmissions.

 

Continue to Part 2