Tech Talk: Ultimate 40/55 Series Disc Brake Conversion Parts Thread (Work in Progress) (1 Viewer)

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Skip anything that has you reusing course spline birfield outer axle and uses adapters to fit GM calipers and rotors. Like hard pass skip. These require you to re-use your course spline (low strength) outer birf joint and free-wheel hubs, both of which have no options for upgrades. If you have a 1958-10/67 4x axle, you'll also want to upgraded your entire front axle assembly not just the knuckles/brakes. The 1958-10/67 axles don't feature an inner axle seal (can be overcome with a conversion seal) but also have smaller diff studs, course spline inner axle shafts, etc. You can find inexpensive 68-75 front axle housings and differentials that will be great recipients for the disc brake parts. Likewise 1958-7/1970 Land Cruisers have a smaller 9mm brake line system, both at the master cylinder and the hardlines, hoses and wheel cylinders. Any disc brake upgrade is going to be 10mm fittings and thus you'll either need to convert from 9mm on the frame to 10mm on the axle OR upgrade your entire vehicle to the 10mm lines. This will also hold true for the master cylinder. If you choose to upgrade the master on your 9mm fitting 1958-7/1970 Land Cruiser, it too will only be available in the common 10mm fitting, so you'll need to address that as well.

Where to get the disc brake parts:

Source a donor axle from a 9/75-1/90 4x/5x/6x/7x Land Cruisers or a 79-85 PU/4RNR with factory disc brakes. Generally speaking the later the parts, the better, bigger steering arms, better brakes, etc.

Armed with the core axle, a good rebuild kit and some minor conversion parts (depending on the source of your donor parts) you can swap all of the disc brake components from the disc axle to your existing drum axle (so long as you have a 1968+ axle housing) and it stays all Toyota.

Don't forget to address your master cylinder by either modifying the front circuit to work with the discs (delete residual valve) or replace with a new cylinder, the FJ80 cylinder is a popular option. You may also consider adding a vacuum brake booster (though not mandatory), all 1958-7/70 Land Cruisers will have a rib on the firewall that will either need to be removed (not always ideal) or use a brake booster adapter to mount a common 6x/7x/8x booster. Some engine conversions will make the longer booster/master tough to fit.

All in it can be done for $500-1000 depending on parts needed (Can the used rotors be resurfaces/turned? Are the used calipers serviceable? Wheel bearings in good shape? Etc). Perhaps even cheaper if you get a good deal on an axle and it's in good shape.

Consider your donor axle:

9/75-1/79 4x/5x: Easiest as parts are a direct swap, no grinding, no conversion steering arms or shims, no swapping inner axles on the disc birfs. Downside is a less common birf, small knuckle studs/pattern (but the same as your current drum axle pattern so you can reuse your current hardware, steering arm and bottom bearing cap if needed). You will need everything from the birf outward (birfs, knuckles, spindles, hub bodies, calipers, free-wheel hubs). Combine this with a knuckle rebuild kit and minor parts and you're ready to convert your front axle.

1/79-1/90 4x/5x/6x/7x: Bigger parts but a bit more swap work, you need to grind the inside of the axle ball (super well documented), convert steering arms and swap an inner axle shaft with your original if using the longer 6x stuff. As these are far more common (6x in particular) this is likely the best solution and gets you birfs that are easy to upgrade/source should you start pushing them hard. You can also upgrade brake calipers to the 89-95 V6 PU/4Runner with some minor backing plate trimming. You will need everything from the birf outward (birfs, knuckles, steering arms, bottom bearing caps, spindles, hub bodies, calipers, free-wheel hubs). Combine this with a knuckle rebuild kit, tie rod end shims (Part# TRESHIM) and minor parts and you're ready to convert your front axle.

79-85 PU/4RNR: Requires grinding, steering arm conversion and swapping both inner axles with your current ones (nothing to be afraid of). Worth upgrading these rotors/calipers to vented while you're there. Same birf as the 79-90 Land Cruiser too. You will need everything from the birf outward (birfs, knuckles, steering arms, bottom bearing caps, spindles, hub bodies, calipers, free-wheel hubs). Combine this with a knuckle rebuild kit, tie rod end shims (Part# TRESHIM) and minor parts and you're ready to convert your front axle.

(It's late and but I'm pretty confident on these dates/specs

If you don't want to bother with used OR your donor axle is missing some of the parts, we can help there too!

You need:
LH Disc Brake Knuckle (Available new @ Cruiser Outfitters)
LH Steering Arm (these must match your knuckle era)
RH Disc Brake Knuckle (Available new @ Cruiser Outfitters)
RH Steering Arm (these must match your knuckle era)
(2) Bottom Knuckle Caps (these must match your knuckle era)
(2) Disc Brake Spindles (Available new @ Cruiser Outfitters)
(2) Disc Brake Birfield Joints (Available new @ Cruiser Outfitters)
(2) Disc Brake Wheel Hubs (Available new @ Cruiser Outfitters)
(2) AISIN freewheel hubs (Available new @ Cruiser Outfitters)
LH Caliper & Support Bracket (Available new @ Cruiser Outfitters)
RH Caliper & Support Bracket (Available new @ Cruiser Outfitters)
Brake Lines (Available new @ Cruiser Outfitters)

Other parts to consider: (All available from CruiserOutfitters.com - part numbers will be added soon)
Front Knuckle Overhaul Kit (1 x Part# FA7590, FA7590KWB or FA7590KWB)
Inner Birf Clip (2 x Part# FACL27091)
Tie Rod Ends (Part# TRE69045 or individual ends)
Tie Rod End Shim (2 x Part# TRESHIM) - Required when using 6x/7x Series and/or 4Runner/PU donor steering arms.
Replacement Brake Calipers (1 x Part# BRC60021LOAD)
Replacement Brake Caliper Hardware (Included with BRC60021LOAD)
Replacement Brake Pads (Included with BRC60021LOAD)
Repalcement Brake Rotors (Available @ CrOut)
Replacement Brake Hardlines (Available @ CrOut)
Replacement Brake Hoses (Available @ CrOut)
Backing Plate Eliminator Kit (Available @ CrOut)
Front Wheel Studs (inspect donor axle studs) (Available @ CrOut)
Knuckle Studs & Hardware (inspect donor axle studs or available @ CrOut)
Hub Studs & Hardware (inspect donor axle studs or available @ CrOut)
Spindle Hardware Kits (2 x Part# FA60011K)
Replacement AISIN free-wheel hubs (inspect hubs from donor axle or available @ CrOut)
Brake Master Cylinder upgrade (Available @ CrOut)

Parts:
1905065

Brand new OE calipers with all Japanese parts! - Part# BRC60021LOAD

1905069

Pick your color of AISIN hub. Wes stock these and more @ Cruiser Outfitters

1905066

We have a variety of new bird options from RCV, Nitro, Longfield, etc

1905067

We have several different disc brake spindle options, Japanese, Chromoly, etc.

1905068

Finish off the disc brake conversion with a new spindle nut kit

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Great info source Kurt!

Have you ever considered stocking the 70 series tie rod and relay rods so you can run 60 seies knuckles on the 40/55 housing? Then no need to shim...

We have them here. But we can only buy the 7x TRE kits in 4pc sets unless I want to buy 10+ of each end out of Japan. The stainless shims are so simple and affordable that only a handful of gone that 7x route over the years. Tube is Part# TRET60101. TRE kit is TRE69075 for anyone wanting to go that route.
 
Kurt, what do you suggest for a Rear Disc Brake Conversion on a 40 Series Full Float Axle?
 
Kurt, what do you suggest for a Rear Disc Brake Conversion on a 40 Series Full Float Axle?

TSM. We stock the kit. Do you need it with or without parkbrake?
 
TSM. We stock the kit. Do you need it with or without parkbrake?

I would need it without, since I will most likely use the parking brake on the rear of the H55f/split case.
 
I would need it without, since I will most likely use the parking brake on the rear of the H55f/split case.
Cool, we can definitely help with that in fact I've got one that's an open box special. Uninstalled and complete. I'd make you a great deal on it. Info@cruiseroutfitters.com
 
I would definitely be interested in taking a look at it to see what it includes.
It's the full TSM kit
 
I'm sure it's a nice kit, but it says it's for a semi-floating rear axle.
 
No worries. I sent an email to the address you specified inquiring about it.
 
I found it by going to that TSM website. The address says "semi-float", but the website says "full float". I'm curious what kind of rotor and caliper they use.

 
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@cruiseroutfit - Kurt, I know people eliminate the disc brake backing plates but I prefer to keep them. By any chance does Cruiser Outfitters sell replacement backing plates? For reference, the axle I'm rebuilding is from a 1979 fj40. I started blasting the backing plates and some areas are pretty corroded away. Thanks.
 
@cruiseroutfit - Kurt, I know people eliminate the disc brake backing plates but I prefer to keep them. By any chance does Cruiser Outfitters sell replacement backing plates? For reference, the axle I'm rebuilding is from a 1979 fj40. I started blasting the backing plates and some areas are pretty corroded away. Thanks.

Unfortunately new backing plates are NLA and very rare, and used are getting harder and harder to find. We sell them only in full disc axle builds.
 

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