Yes, we are based in SLC, Utah. You can order the shims using the link I shared in my previous post.
Another Disc Brake Conversion Thread, but...
- Thread starter Tecagist
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Yes, we are based in SLC, Utah. You can order the shims using the link I shared in my previous post.
A larger TRE would be the 6x/8x TRE and will fit the arm BUT will require custom length tubes as the thread at the tube is very different.
Common 4x/5x TRE's are 21x1.50mm RH & LH thread
Common 80-97 & beyond 6x/7x/8x TRE's are 23x1.50mm RH & LH thread.
They also have different connection points for the relay-rod end so it's not as easy as mixing and matching. The shims are the absolute easiest and cleanest option.
And here is an entire thread on sourcing the right starter bushings. Which Cruiser Outfitters will gladly sell you...
forum.ih8mud.com
As mentioned by the OP - all of this has been covered many times and is all in the FAQ.
Be aware that you could also end up with wheel fitment issues once you fit calipers depending what you are running now.
starter bushing and drum brake TR
I just finished a mini disk swap on my dad's 40 and I am using the drum TR with the mini arms. Obviously the TRE's are smaller than the holes in the arms. I read that you can use a starter bushing as a shim to make the TREs tight in the arms. See here for an explanation...
forum.ih8mud.com
As mentioned by the OP - all of this has been covered many times and is all in the FAQ.
Be aware that you could also end up with wheel fitment issues once you fit calipers depending what you are running now.
My $0.25
In '94 my drum brakes needed to be replaced on my '74 Fj40. Drums were toast, shoes were done... cylinders (no idea 31 years later).
I picked up a complete '77ish front axle that had 3.70 gears in it for $100 (remember it was '94). I had only had a Haynes manual to go by... and it had nothing in it about disc brake conversions in it. As the internet was in it's infancy, I set out blindly to figure out how to convert to disc brakes.
After disassembling both front axles, I found that the '77 fine splined Birfields fit into the July '74 housings. Other I then mounted up the '77 knuckles keeping all the '77 shims, hardware, rotors, rebuilt the original '77 calipers, and threw in a $21 set of pads. The rotors were at the wear limit so I cleaned off the surface rust with sand paper and ran them.
I quickly discovered that the rear brakes would lock up any time I hit the brakes firmly. I asked around and found out that I needed to add a brake proportioning valve in the rear brake circuit. Problem solved. The disc brakes worked great with the original '74 brake master and booster.
Years later I learned that drum brake masters have a 10 lb residual valve and it should only be 2 lb. I suspect that the old residual valves weren't working right because the 10 lb valves weren't a problem. A few years later I removed the residual valve out of the front circuit which didn't seem to change anything. The first set of front brake pads lasted 95k miles and 21 years. They still worked, but I felt they were due.
Around '99 I also converted the rear FF brakes to discs. I won't get into the details here since the OP was about converting to front discs, and I did a one off conversion in a way that I wouldn't recommend now (even though they're truly awesome). I don't regret the way I did the conversion, but there are easier ways now.
A couple things I've learned over the last 30 years since I did the conversion(s). Although the large pattern knuckles from '79ish and newer axles are stronger, I've never had any issues with small pattern knuckles despite running 33 x 12.50 ATs and a 300ish hp SBC. With full size 3/4 ton discs and calipers on the back, an adjustable proportioning valve is a must. I have heard of some owners with 4 discs that didn't need a proportioning valve, but that hasn't been my experience.
A few years back I swapped in an 80 series booster and master. I still need the proportioning valve, but the brakes are super powerful now. I love the way they work, but some find them too powerful.
Some have swapped in 4Runner calipers that have four larger pistons for extra braking power. They need to be ground a bit to clear 15" rims, but I already have a ton of braking power and see no reason for more. Stock discs up front, and the rear discs I have, have more than enough power to stop the 40 while towing a 4,000 lb trailer.
There are many ways to reach the same results... but you can't go wrong with stock Toyota 4 piston calipers and vented rotors.
In '94 my drum brakes needed to be replaced on my '74 Fj40. Drums were toast, shoes were done... cylinders (no idea 31 years later).
I picked up a complete '77ish front axle that had 3.70 gears in it for $100 (remember it was '94). I had only had a Haynes manual to go by... and it had nothing in it about disc brake conversions in it. As the internet was in it's infancy, I set out blindly to figure out how to convert to disc brakes.
After disassembling both front axles, I found that the '77 fine splined Birfields fit into the July '74 housings. Other I then mounted up the '77 knuckles keeping all the '77 shims, hardware, rotors, rebuilt the original '77 calipers, and threw in a $21 set of pads. The rotors were at the wear limit so I cleaned off the surface rust with sand paper and ran them.
I quickly discovered that the rear brakes would lock up any time I hit the brakes firmly. I asked around and found out that I needed to add a brake proportioning valve in the rear brake circuit. Problem solved. The disc brakes worked great with the original '74 brake master and booster.
Years later I learned that drum brake masters have a 10 lb residual valve and it should only be 2 lb. I suspect that the old residual valves weren't working right because the 10 lb valves weren't a problem. A few years later I removed the residual valve out of the front circuit which didn't seem to change anything. The first set of front brake pads lasted 95k miles and 21 years. They still worked, but I felt they were due.
Around '99 I also converted the rear FF brakes to discs. I won't get into the details here since the OP was about converting to front discs, and I did a one off conversion in a way that I wouldn't recommend now (even though they're truly awesome). I don't regret the way I did the conversion, but there are easier ways now.
A couple things I've learned over the last 30 years since I did the conversion(s). Although the large pattern knuckles from '79ish and newer axles are stronger, I've never had any issues with small pattern knuckles despite running 33 x 12.50 ATs and a 300ish hp SBC. With full size 3/4 ton discs and calipers on the back, an adjustable proportioning valve is a must. I have heard of some owners with 4 discs that didn't need a proportioning valve, but that hasn't been my experience.
A few years back I swapped in an 80 series booster and master. I still need the proportioning valve, but the brakes are super powerful now. I love the way they work, but some find them too powerful.
Some have swapped in 4Runner calipers that have four larger pistons for extra braking power. They need to be ground a bit to clear 15" rims, but I already have a ton of braking power and see no reason for more. Stock discs up front, and the rear discs I have, have more than enough power to stop the 40 while towing a 4,000 lb trailer.
There are many ways to reach the same results... but you can't go wrong with stock Toyota 4 piston calipers and vented rotors.
