Here's the completed assembly....
Here's the completed assembly. There are shiny new rotors, calipers and Warn hubs. A completely rebuilt frontend, fresh from hub to hub, as promised.
Regular readers will recall that last month we documented the procedure for a Saginaw power steering conversion on an FJ-45, and gained more steering control, at less effort, for our pains. This month, we focus on the axles. The differentials come from a '77 FJ-40 with front disc brakes; our '65 stocker came with drums.
Both front and rear get new 4.88:1 gears, while the front receives new Marfield axles and a complete rebuild. "From hub to hub, it'll be totally fresh,'' says Downey Offroad's Jim Sickles, the buildup's architect. That means rebuilt steering knuckles, new rotors, calipers and Warn hubs-the works. The rear diff is already stuffed with an ARB, so when this particular FJ is finished, it should be plenty stout on trail. The rear will also be prepped for its imminent disc brake conversion.
 The whole brake assembly saw...  The whole brake assembly saw its day long ago, and has the rust to prove it. The caliper is being removed here; hubs and rotors come next. Normally, you'd want to be careful when removing rotors, but since these are going in the recycling pile, they were removed with a good whack from a mallet. A note on the backing plates: In stock configuration, brakelines would be supported by them en route to the calipers. But new brakelines will go from the diff housing straight to the calipers, so out go the backing plates and old brakelines. |  The grimy old steering knuckle...  The grimy old steering knuckle being removed. But first, the half-shaft has to be removed, and there's a trick to this: you need to line up the flattened side of the Birfield joint with the four bolts atop the steering arm. Next, unbolt the steering arm, then proceed with the knuckle removal. Once you've removed the rotor and spindle, the shafts can be removed at any time since the frontend has no C-slips. |  The knuckle, bearings and...  The knuckle, bearings and oil seals will be replaced, and the old axle shafts pulled and upgraded with stouter Marfields. In this shot, the carrier is drained of oil, after which it can be opened. Finally, the old ring and pinion are pulled, never to rear their greasy heads again. |
 Ideally, you want a press...  Ideally, you want a press to remove the old pinion bearing from the shaft and install new bearing on the new pinion shaft. While there are smaller tools available to do this, none are quite so exact. The new pinion gear will require a crush collar, whereas the original took shims. |  The carrier housing needed...  The carrier housing needed a spray of fast-dissolving solvent, and a quick going-over with the sander at the flanges to remove old gasket, adhesive, paint and grit. |  Our mechanic suggests greasing...  Our mechanic suggests greasing the pinion seal. This keeps the inner spring from being knocked out of the seal during assembly. |
 After checking pinion bearing...  After checking pinion bearing preload, put the appropriate sealer on the pinion and rear gear nuts and reattach the cap. |  The center pin is a little...  The center pin is a little too big for the new ring gear. It will require a little grinding at the ends to fit. The rear pin will have to be ground, not on the ends but on its flat side, parallel to the existing round hole used for the locking pin. Don't file on the rounded side that's 90 degrees or perpendicular to the original round hole-that's the side the axles rest on. |  Once the new gears have been...  Once the new gears have been loaded in, check backlash with a dial indicator. Do this in three spots equally spaced around the ring gear to ensure that it matches manufacturer's specs. Then use marking compound to check the smear pattern. You want the pattern to fall in the center of each tooth. |
 Once the rebuilt third member...  Once the rebuilt third member has been reinstalled, you're ready to start reattaching the hub and brake assemblies. Here, the knuckle bearing cup is hammered in. Be sure to check bearing preload with factory specifications, then coat them with grease. The inner oil seals are new. Now the knuckle can be put on. |  Once the knuckle is on, and...  Once the knuckle is on, and the inside is lined with grease, the Marfield axle shafts are ready to go in. Then more grease is packed in, and the half-shaft goes back in. |  The rear also received new...  The rear also received new 4.88:1 gears. Note the blue air tube-there's an ARB in there. |
 Remember that mallet? Here...  Remember that mallet? Here it is in action. The rear will receive a disc brake conversion, to be covered in the next installment. | | |
Project FJ-Hybrid - Part I
Project FJ-Hybrid - Part III
Project FJ-Hybrid - Part IV