fj drivetrain inspiration

 

This FJ has served as the major inspiration for the drivetrain in my current FJ40 stretch project. It has the same engine that I am using and I used the same method of flipping the front differential. The pics of been helpful in identifying how I want this mechanical build to look. The images are from this article. 

fj/hj 47 front driveshaft

Putting the transfer case from the 4Runner in the FJ40 has caused all sorts of issues. I knew this would be the case since the stock FJ40 is passenger side differential and the 4Runner/Tacoma is driver’s side differential. I solved that issue by cutting the front axle pumpkin off, notching the housing for the 3rd member flipping the drain plug from bottom to top; which became the bottom when I flipped the axle, and cutting and flipping the end knuckles. Again this axle issue was solved a long time ago. But that still doesn’t connect everything to provide 4wd. 

The front driveshaft needed to have a carrier bearing to work with the leaf spring from axle since the driveline would be flexing. Yesterday I decided to tackle this project. I used a two piece rear Tacoma driveshaft and cut it up to make all the pieces I would need. I’ve gotten half way decent at making new custom length driveshafts. Luckily these are smaller sections, so I can true them and set them up for welding on my 13” South Bend lathe. Using the rear driveshaft for my front driveshaft allowed me to have larger u-joints for strength but it then caused an issue with the small bolt pattern on the pinion flange from the stock FJ40 axle. 

My neighbor assisted me on this and made a plate that I could drop the stock flange into and weld. Then I recut the larger profile of the plate and drilled holes to match the new custom driveshaft flange. I could have left the pinion flange alone and used a conversion u-joint but I thought keeping all the same u-joints was a better move. I made a mount for the carrier bearing that comes off of the transmission crossmember. It all turned out well. 

I now know that my front section of driveshaft is the correct length (after my initial guess) and now I can fully weld this. One step closer…

 

fj47/hj47 new year progress

The new year is here and I'm back into the stretched FJ40. I reinforced the rear leaf spring mounts yesterday and cut the box plates and cut holes in them. Today I started the day with welding in more boxing plates in the rear section of the frame. I still need to grind down the welds but it's going to look good when it's all smoothed. I machined one of the rear rotors for the disc brake conversion that I'm doing. I had to take the axles out of the axle housing to get the old drum backing plates off (I could have cut these but I might end up selling them to someone who wants a stock drum setup). I wanted to do a complete refresh on the rear differential and axle housing so that's alright. I'll end up making the caliper mounting brackets. I found a template online so I can make that plate pretty easily. I'm using chevy truck rotors that need the center opened up on the lathe to fit the Toyota axle ends. I'll use Monte Carlo calipers with this setup. I did this on the front of my old FJ40 and it was transformational. I always wished that I would have done the rears on it, so this should be stellar. It feels like all this stuff takes forever to do, but I have to remind myself that one thing leads to another. I ordered new leaf spring bushings, so I'll start tearing the spring packs down and fully remove the rear axle housing so I can get the housing ready for paint. I'd like to try my hand at re-arching the leaf springs to get a little lift. I'm concerned that the rear driveshaft may hit one of the crossmembers that was designed for a shorter wheelbase FJ40. Getting some lift on things would let me clear larger tires and make it so I don't need to modify that crossmember.

Things to do before I paint the frame:

Make front power steering brackets for Saginaw steering box.

Weld saginaw mounts in place.

Check body mounts to make certain I have everything welded in the correct place.

Check steering shaft angle and position in accordance with the 5VZ engine.

Weld in threaded brake line mounts inside frame.

Figure out if I need any mounts for fuel line.

Figure out if I need any tombstone mount tabs for the rear brake lines welded to the axle.

Weld in front carrier bearing mount; figure out front driveshaft setup.

Remove any unwanted brackets on frame (from old trans/transfer case).

Patch any inside frame holes that need to be reinforced.

Fully weld and grind everything and then sand the frame.

Attempt to re-arch the rear springs.

Pull the engine and paint frame.

Order:

Shocks for all four corners.

Front axle rebuild kit.

 

scratch built toyota fj47 "troopy"

Sometimes you get excited about a project and your hands can't move fast enough for brain. Your imagination and creativity take over and supercharges your senses and makes you skip steps and make stupid decisions. It's sometime difficult to slow down and do things right. 

During the pandemic I started to visualize and dream about owning a Toyota Troopy or FJ/HJ 47. I was starting to see some of these showing up in the States since they were now legal to import from Australia or South America, but I still couldn't afford what these rusted out hunks were selling for.  I had come across some extra parts when I was restoring an earlier project FJ40 and I happened to have a rusted out frame and another good frame, so my brain started working overtime. I had some time off work due to the pademic and in a few weeks I had a frame cut upand pieced together and I started going to town mocking up rusting sheetmetal. I kept telling myself that I was just trying to see what it might look like and just wanted to see if I had the parts to make it all come together. I stalled out when I was trying to figure out what drivetrain I would put in it.

Once the pademic was over, my neighbor came over and saw it and we were talking about drivetrains and he said that he had a Toyota 4 Runner that was rusted out but that had a good engine and trans that he would give me. The wheels started turning again and In a couple of days I had a Toyota 5VZ 3.4L leveled up and had the transmission and transfer case mounted. I even got the crossmembers welded in and started thinking about a gas tank solution. The front axle on a stock FJ is passenger side diff but the 97 4Runner requires driver's side dif to make the transfer case hookup. My neighbor and I had talked this over originally and he was urging me to use the 4runner frame, but I really wanted the solid axle setup and the measurements would require widening the FJ40 body which I think ruins the proportions. Would you think that this hurdle would have stalled me out, but I I figured I could take the stock from axle, cut the dif housing off, cut the axle knuckle end off and flip it all around and weld it back in place. One might think that it's just a simple flip of the axle, but that would give send you in reverse when trying to drive forward. Anyway, I go through this and I was one step closer.

Now in my mind, I kept hitting a hurdle as the logical side of my brain knew that I had not previously buttoned up all frame issue from the initial stretch and moving forward with the body fitment didn't make sense until I had had a proper rolling chassis. I had gotten parts for a disc brake conversion, but the frame just wasn't a strong foundation to build on. 

That brings me to this week. Now that I was off school, I decided that I needed to strip the body back off and address all of the issues with the frame. I could box the frame while I was at it, figure out my gas tanks mounts, reinforce any of the crossmembers, put in my front carrier bearing for the front driveshaft, paint the frame, run brake lines, run fuel lines, install power steering, and finalize the disc brakes, axle rebuilds, and get this mega long frame into a rolling chassis.

In the past few days: 

I made box sections for the middle of the frame where I added 26" of frame. I cut holes similar to the stock frame in these sections and got them tacked in place. I finalized the position of my chevy blazer gas tank, adapted the 4runner style sending unit and made a crossmember and mounts for the tank. I still need to make lower straps, but I'm close on this.

Welded nuts to the inside of the frame for the bump-stop mounts.

I made plate sections to box in the frame over the axles and got them welded in.

I ordered some POR 15 to paint the frame and I started cleaning up surface rust on the frame.

I finished welding in the motor mounts and fully welding the crossmember for the transmission mount.

After today, I still need to:

Make some more plates to box in the rear section that is added onto the frame ( I have made templates for these).

Finish welding the diagonal braces at the rear of the frame.

Patch any unused holes.

Weld in a plate for the power steering box mount.

Take a stab at re-arching the leaf springs and cleaning each individual leaf in all of the leaf packs.

Machine my Chevy truck brake rotors.

Make rear caliper mounts for the Mote Carlo brake calipers

Rebuild the axles

Check the 3rd member gear lash.

Order a saginaw steering box

Order a set of shocks

Order new leaf spring bushings

Order a new set of tires

Order brake line material

Order axle seal kit and possibly axle bearings.

I know this doesn't look like much but it feels like a big step in the right direction. There's still a lot to do, but I feel like I've at least slowed my brain down a bit and I'm working on getting the foundation right before moving onto the body. However, I'm excited to get to the sheetmetal because I'm planning on making some tooling so I can recreate some of the sheetmetal from scratch so that the final result is better crafted. I'm stocked to get all the welding on the frame finished so I can lift the drivetrain out with my hoist and I can drop the axles and do a full on quality paint job on it. I'm trying to think of the frame like a piece of sculpture, so I'm going to try and smooth everything on it.