Bill

Alright, so I'm set ono doing a rear disc swap on my 86 pickup. I've looked at all the "normal" ways of doing it, but hey this is a project, whay not have experiment?

So I've been thinking of ways to do the swap using "standard" toyota parts. I took a look at a set of Landcruiser rotors(81+), and I'd need to double check, but they seem big enough to hit over the hub, and they are the same thickness as stock 4cyl/early V6 discs (~7/8"). My only concern is that they may not fit over the flanges on the rear axle.

This got me thinking: My front brakes use 7/8" rotors, and I've already swapped my front brakes to larger V6 calipers(and MC), so mabey try to reuse my 4cyl calipers. I'd certainly be able to stop good.

It seems though that the standard for rear calipers is to use floating calipers. Makes sence too, seeing that the mounts don't have to be "quite" as perfectly spaced. That precision os what is making be a bit leary of using 4cyl 4x4 calipers.

So finally, the info I'm looking for:
1: Rotor thickness on 2WD trucks with floating calipers
2: Landcruiser Rotor diameter(outside)
3: diameter of the inside of Landruiser rotors(the recessed part on the back)

I plan on starting my swap as soon as I get my 5-speed swapped in(over the weekend). And oh yes, there will be pictures.

waskillywabbit

iTrader: (-1)

I just built a full-floater rear end on my 85.

This is what I did...which I would think would be very similar...so it might be helpful.

*FROR's adapter and a SFA spindle and wheel hub
*FJ62 vented rotors (1989) as they have 8 holes to fit on the wheel hub (2 bolts and 6 wheel studs)
*87 IFS 4 cyl loaded calipers Beck/Arnley

Everything fit up fine, calipers rubbed a tad, but nothing a quick grinder didn't fix.

Good luck.

Bill

sounds pretty much like what I'm wanting to do. Did you have to press the studs into the rotor, or simply bolt the rotor to the front? I'm trying to be as bolt on as possible, but if it comes down to it, studs arn't too tough to deal with.

As far as the mounting bracket, I was planning on making that myself. Gives me something to do for a weekend.

waskillywabbit

iTrader: (-1)

The wheel studs on the rear axle are pressed into the axle housing end flange and the rotors just slide over them...in your case.

rockota

Don't forget to mention that this is essentially a duplicate of the solid axle front end. Brian normally recommends the non-vented rotors with stock calipers or Supra calipers (for the e-brake), but Wabbit took it one step further and duplicated the front setup out back.

This is a bolt-on Full-Floater kit and not something cobbled together.

Also, there is a reason why only one shop produces an "all toyota" rear disk brake kit; there are better methods.

toy283

To fit the rotors over the hub flange, pull the axleshafts out and take them to a machine shop and turn down the diameter enough to fit inside the rotor. For studs, front studs from an Eagle Premiere have the correct pitch but have a longer shoulder length. This means the holes of the rotor are seated against the shoulder of the stud opposed to against the threads. For calipers, I used 2nd gen ('89-'91) Camry rear calipers. These do not have an e-brake on them though, Camry's used a disk/drum hybrid in the rear (the e-brake was the drum portion). The rotors I used were a set of stock solid front rotors that I took off the front of my 4Runner when I did the vented upgrade.

Bill

I'm not looking to do a full floater...yet.

As for there being "better" methods, yes I'm sure there are. I've looked quite bit into this swap, and I see the same thing over and over again: chevy rotors with chevy calipers. Why? Because it works. I fully admit this, however I like taking the road less traveled. So I'm trying to do this with a few things in mind:
1: no maching.
Making brackets is one thing, but if I'd need to take my rotors to a machine shop everytime I need to replace them, it's a bit of a pain(not that it's frequent, but what if I sell it?)

2: Use parts I already have.
I've got a set of toyota 4cyl 4wd calipers sitting on my work bench, why not try to use them?

3: Keep stuff metric.
This makes fewer sizes I have to worry about fumbling through. Plus all my calipers will still have the same fittings.

And I just got my Allpro t-case brake tonight, so I don't really have to worry about the whole lack of an e-brake issue.

Elvota

I am looking to learn about all the disc brake options out there and I to would rather keep things Toyota and all metric if possible.

Bill, WaskillyWabbit.... what will both of you do for a proportioning valve? It's my understanding that the stock V6 MC won't work well once rear discs are added unless you do some sort of valve or upgrade to a LC MC.

I also have the front discs and calipers off my '85 Toyota front axle from when I did the SAS. Seems like if those parts could be used in the rear, many other SAS'ers would be interested... but maybe the catch I am missing is why it's not possible to do.

toy283

It is possible to do and has been done. The problem is that the hub flange on the axleshaft is larger diameter than the i.d. of the rotor hat. To get around this there are two things you can do:

1. Mount the rotor on the inside of the flange. To do so, the inside of the flange should be trued up on a lathe because in most cases, it is a rough casting and the rotor may not sit flat against it. Also, the rotor must be held in place by pressing the studs through it and into the flange.

2. Turn the hub flange diameter down on a lathe until it is no longer too big to fit inside the rotor hat. Do not go too far though as you can get too close to the stud holes. This is essentially what I did but my axlshafts are custom and are quite a bit thicker than the stock Toyota ones.

Both of these solutions require a little machine shop work, but it is a one-time affair as opposed to using Chevrolet rotors which must be machined every time they're replaced.

waskillywabbit

iTrader: (-1)

There are too many Brian's floating around in this conversation.

My non-vented SFA rotors were new ones that I had put on when I did my lift, but my 85 SFA calipers were toast, not worth a rebuild, so I just upgraded since I was going to spend a buck or two anyway.

I've had the All-Pro rear disc brake kit and it worked well too...I just wanted to be all Toyota and now I can carry a couple of spare parts and cover the whole braking system.

I too am a fan of keeping things all one standard...either SAE or metric...I freaking hate having to remember which is which and where...so I fixed that on my rear disc setup while I was there.

The All-Pro t-case brake rocks. You'll like it and from my research the supra calipers didn't make folks too happy.

You WILL need a manual proportioning valve. Put it up by the MC inline to the rear discs. Lots of 411 on the Toyota FAQ on Pirate how to do this, or I can tell you. Not hard at all.

Yep, the front rotors and calipers can be used in the rear, but it will take some machining and a bracket or you can do a full floater and it is all bolt on easy.

A worthwhile upgrade for sure IMO.

Bill

This is exactly the problem I was worrying about.

I figure that the decision about which way to solve it will come down to the width of the caliper itself, and the distance from the mounting surface to the rotor surface.

If if I can mount the rotor over the studs and not have the caliper contact the wheel, too easy. If not, I'll get some longer studs and mount it of the back.

As for a proportioning valve, I second checking pirate. Lots of good info about them on there. I'm planning on getting one off eBay, you can pick them up for $30-70. Once I get it on, I'll decide if I want to use a residual valve as well.



**Side note*** can anyone tell me if the axle shafts from an 87 or 88 4Runner will work in an 86 pickup? I'm only asking because I know that the 4Runners have a 1/2" axle. If they will great. I'd like to mock up my brakes on a spare set of axles, before digging into mine onto to find I ĊĊĊĊed something major up.

HAVOC

You can stop in at Your local NAPA or other parts store and ask them if you can look at each part you listed. Have your tape measure and pencil/pad ready to write down measurements.
It helps if you buy something while you're there, so they don't think you're wasting their time.