Rear FF Disc Conversion (1 Viewer)

[Shawn Russell]

Has anyone else done this? ( Rear Full Floater Disk Brake Conversion )

I have had nothing but problems with this conversion. The instructions look VERY simple, however, it turns out to not be.

I bought the brackets from a fellow 'Mud member. They would not fit around the flange, had to have them bored. If you look close at the photos in the link, it looks like he had to do this as well, but there is no mention of it. (I sent an email before I started, and got no response)

I got the FJ60 wheel studs, and they will not fit in the hub. They are about .040 too big to fit in the hole. So I either have to cut the studs down, or drill the hub. Again, no mention.

I have yet to get to the calipers. I wonder how many issues I will find there...

I will do another write up when I am finished, if I am successful.

 

[TinBox]

I bought the brackets from Jim at Downey. Two brackets 6 bolts 6 nuts 6 washers $130. Then I when to Chiefs auto parts, 2 Chevy rotors $28 for both. 2 Chevy Monte Carlo calipers $25 loaded lifetime warranty (calipers and pads) and caliper 4 bolts $4. 2 brake lines $17 each. 1, 6’ steel line. Cut steel line in half use fittings on stock toy lines. 6 years later still working good. Best part is I can get all parts at any store if I need them. Nothing is like knowing that if you need parts to fix something on Rubicon and Dusy you can get them same day.

 

[petescoffee]

No issues with the kit from TSM either (Monte Carlo). Are you doing a Toyota Rear Disc Set up or a Chevy rear disc swap?

 

[Vicm]

Are these bracket that you got made from scratch or made from front knuckles?
How much?

 

[Shawn Russell]

They were made from front knuckles...

Shawn

 

[Downey]

For those more inclined to buy something already machined and ready to bolt-on, we could be the answer:
(a) our rotors are already piloted onto your wheel hubs, plus we relieve the back side for FF rear ends on all rotors.
(b) We have separate brackets for Semi and FF rear ends, each providing the proper caliper placement.

It's true that you would be dumb to buy anything from us that you can get cheaper in your own town, but at the end of the day I bet you sure would be happier if you could get your hands on our instruction sheet.

 

[Vicm]

They were made from front knuckles...

Shawn

Making them like that is not only sad, but also wrong.
Who ever is making them could do a whole lot better than that if they started with raw metal.
For someone who wants to make their own brackets, using front knuckles maybe understanable.
You did say how much.

 

[belaw]

Do any of the after-market brackets support Toyota calipers?

Shawn, I look forward to your write-up!

 

[Shawn Russell]

Why is it wrong?

 

[TinBox]

You are all missing the point of simplicity and available parts at a good price.
Shawn is having problem installing everything, cutting the cast knuckles might weaken them. I know that some people like to stay all Toyota but $120 for 2 calipers plus $150 bucks for 2 rotors not vented. 2 Custom Flexible brake lines what did that coast? Can you get these Custom Flexible brake lines at any auto part store? My conversion was less than $225. Some people don’t wheel far from home and some do. But if I drove my FJ40 to Moab or some other long distant place, replacement parts are important to me. Plus I don’t want to carry them or spend money to have an inventory with me.

 

[Shawn Russell]

Once I get all of this together, the only thing not "off the shelf" will be the brackets. Same as if you went with the Chevy parts. I will not even have to machine the rotors to get them to fit. At least that is the idea.

I got the brackets for $65.00 total, and another $40 to have the center hole opened up.

Shawn

 

[Tazman75]

Shawn, I'm busy with the same conversion (Not complete).. I imported a '75 FJ40 from Aus with FF and replaced the front drum hubs with 60 series disk hubs and decided to go for the 60 cut hubs in the rear with 60 calipers to keep it the same front and back. AM brackets are not readily available locally as I believe we have less than 15x 40's in the country.

I found the following:
1) Cutting the hub and opening the new bracket to fit around the axle was do-able at an engineering shop.
2) After the cut I had to open the ID of the bracket with about 0.5mm to accommodate the ridge on the diff housing (located on diff housing behind the drum mounting). This I did by working off about 1mm at a 45 degree angle to fit over the ridge. This created a flush fit to the housing. Used the original studs to mount the bracket.
3) I had the rear of the hub skimmed to provide a smooth surface. Removed 1mm.
4) Installed new wheel bearings, new ventilated router (60 series disk), new longer 60 studs + washers and torque the wheel nut. Providing a flush mounted bracket and all new setup.
5) Mounting the caliper revealed that the router (disk) was not centered. 0.1mm on the outside and +/- 4.8mm on the inside. (measurement between router (disk) and the nearest point on the caliper casing. I had to move the bracket closer to the outside.

This is where I stopped. What I want to do next is to have the bracket face skimmed with 2.4mm to center the caliper.

In theory that should provide the conversion I'm hoping for.

I have pictures of most of the above but need to upload first if required..:whoops:

 

[Henry James the 47th]

Curious...I did this conversion on my truck making mounting brackets from the sliced knuckle housings, and it went really smoothly and the calipers were centered when I bolted them up. The only fiddling i have had to do is with the stud lengths. I sliced the knuckle housings up using a zip wheel on a grinder, and other than the small mount of machining needed on the back of the hub to mount the rotor, everything went smoothly. I wonder what the sources of the problems are with your set up?

Check page 8, post 214 onwards, on my build thread and see if I did anything any different (build thread linked at sig. line)

 

[Tazman75]

Henry, what calipers did you use for the rear? I'm making use of OEM 60 series. Yours look differnt? The FF axle at face value looks the same. My origional hubs stud holes started to go oval and the previous owner welded them in place. The reason for skimming the rear of the hub. It could be that they skimmed more than the requested 1mm? Also possibly explaining the more of an off-set to the outside.

Very impressive build by the way - My 1975 40 still needs to go down that road.

 

[Henry James the 47th]

For the rear calipers I decided to go "a little overkill", and put 4-Runner calipers on. I also used these on the front brakes. They have 2 large pistons, instead of the one-large, one-small set-up of the 60 series LC calipers. The problem with the 4Runner calipers is that they are quite wide and will rub on most wheel rims - I put 70 series steel rims on (only cost about $70/ea from the dealership in Canada!) and they have generous clearance.