WrenchTech
New member
Yes, Diamond Axles in Colorado sells a custom housing so you can upgrade your 8” or 8.2 inch FJ Cruiser to a 9.5 dif
Rear Disk Brake Conversion Pt 1
- Thread starter Rockdawg84
- Start date
Yes, Diamond Axles in Colorado sells a custom housing so you can upgrade your 8” or 8.2 inch FJ Cruiser to a 9.5 dif
WrenchTech
New member
I emailed Diamond Axles this morning to see if someone over there would tell me how wide an FJ Cruiser rear axle is. The word I got back is that they are 64.5" wide. That makes them about 3.75" wider than a stock 3rd gen 4runner axle. Seems like it would do well paired up with a 63.5" Landcruiser FJ80 front axle in an SAS situation.
Rockdawg84
New member
FJ rear Axle is to wide. it is the same as a 4th gen. Everything would have to be cut off the axle and then rewelded on in the right place. Not worth the work in my opinion.
WrenchTech
New member
Right, especially when you could get most of what you want with a bolt on kit from Front Range Off Road Fabrication.
Rockdawg84
New member
The D-Rotor is actually better than a FJC or 4th gen axle because it is a full float axle not a semifloat. So Much better:hungry:
Looking at the price for the bolt on. Plus, sourcing the calipers. Idk.... it’s not hard to buy pre made mounts to be welded. Just opinion. Either way it’s not cheap.
WrenchTech
New member
It would still be 3.5” wider. An FJ80 axle, with a 9.5” differential, full float, and disc brakes can be had for surprisingly little money. Probably due to the fact that the differential is off center by 3.5”. If you cut 3.5” off the long side you could have a 60” wide axle that uses a second short-side shaft on the cut side. Of course you’d have to make a pretty good jig to align and it while u were welding it up.
jkeith.w
Official Vendor
oh, this sounds interesting...
Jaysen4runner
New member
I would only want a wide rear to match LT. Beside that there no point of having a wider rear end.
sleepydad
Senior Member
I'm almost to the point... calling diamond and having them just make me a custom rear axle assembly full floating style. stock setup for a 3rd gen + the ebrake stuff as well.
I think it might be cheaper in the long run and I get everything I want. need to figure out a way to sneak the rear axle assembly into the garage without my wife seeing it.
oh honey it's just a plant stand.
(⌐▨_▨)
Rockdawg84
New member
yes there will come a day when I bend my stock housing and I will call Diamond and have them build me a housing. I already have everything else, full float conversion, axles and I have figured out how to maintain ABS which is the major downside to the FROR Full Float conversion. I just need to take the time and get my Ebrake hooked up.
WrenchTech
New member
I've made some progress on the Sleepy Dad version of the rear brake conversion so far. This approach uses the late 90s Mustang GT rear calipers and 4th generation 4runner rear rotors. The adapter bracket is made out of 3/8" steel flat stock. I am making these adapters for my 1993 Xtra Cab pickup.
The axle housing pictured here is a rusty spare that I had and the caliper is salvage yard special. I am just using these parts to work out the bracket design. The clearance between the caliper bracket and the rotor is very tight, and so the spacing between the bracket in the caliper needs some adjustment. I am just using a stack of washers to arrive at that final dimension. Initially I installed a stack of two washers that we're each roughly.090" thick each. That pushed the caliper out to the point where there was between zero and one hundredth of an inch of clearance on the inboard side of the bracket. I went to the hardware store with my digital measuring caliper in hand and found some washers that were .065" thick. It looks like a stack of washers made up of one of the thicker ones and one of the thinner ones (.090" + .065) results in additional clearance. The caliper bracket is still not perfectly centered, it is still a little bit tighter on the inboard side, but it will probably work.
I'm posting a preliminary diagram of the bracket with the dimensions that I've worked out. Working on this project has been a lot of fun, particularly figuring out the dimensions and seeing the resulting numbers.
The axle housing pictured here is a rusty spare that I had and the caliper is salvage yard special. I am just using these parts to work out the bracket design. The clearance between the caliper bracket and the rotor is very tight, and so the spacing between the bracket in the caliper needs some adjustment. I am just using a stack of washers to arrive at that final dimension. Initially I installed a stack of two washers that we're each roughly.090" thick each. That pushed the caliper out to the point where there was between zero and one hundredth of an inch of clearance on the inboard side of the bracket. I went to the hardware store with my digital measuring caliper in hand and found some washers that were .065" thick. It looks like a stack of washers made up of one of the thicker ones and one of the thinner ones (.090" + .065) results in additional clearance. The caliper bracket is still not perfectly centered, it is still a little bit tighter on the inboard side, but it will probably work.
I'm posting a preliminary diagram of the bracket with the dimensions that I've worked out. Working on this project has been a lot of fun, particularly figuring out the dimensions and seeing the resulting numbers.
Last edited:
phattyduck
Elite Member
What's the thickness of the discs the Mustang calipers are meant for? How thick are the 4th gen rotors? The close clearance might be due to the 4Runner discs being too thick for the caliper design.
Nevermind, looked it up. The (98) GT rear rotors are 18mm new /16mm min like the 4Runner rotors. Make sure you have a GT calipers, not the V6 ones that start at 14mm thick.
-Charlie
WrenchTech
New member
I was just thinking, I only have the one caliper right now. The calipers are manufactured in right side and left side versions. My bracket is a little bit asymmetrical in terms of the relationships of axle flange mounting holes to the caliper mounting holes and so I'm hoping that I don't get any surprises when I go to the left side.
WrenchTech
New member
Thanks for the heads up on the difference between the V6 and GT calipers. When I get the left side caliper I'll make sure I'm getting the correct part.
phattyduck
Elite Member
They also use different diameter discs - so you'll want to make sure you have the correct parts now! Let's hope you don't have to change your bracket.
-Charlie
WrenchTech
New member
I reviewed the different rotor and caliper and rotor options for the Mustang. I noticed that the GT and the Cobra use different rotors. The GT uses a solid rotor that is 13.9mm thick and the Cobra uses a vented rotor that is 18mm thick, but the interesting thing is that they use the same caliper. That is the caliper I am using. The 4th gen 4runner rotor that I'm using is the same thickness as the Cobra rotor, so it seems like it should work. There is also some metal that could safely be removed from the caliper bracket to gain a few hundredths of additional clearance.
Last edited:
WrenchTech
New member
Nothing to worry about on that score. As you can see in pictures I have had the pieces installed together and the fit, in terms of rotor diameter, is fine. Whether my wheels will clear the calipers is another question that remains to be seen. I have 16" steel Daytona wheels right now and I am looking at installing some 17" FJ Cruiser wheels. They have the silver finish from the factory. I think they would look pretty good in black on my dark gray truck.
Last edited:
WrenchTech
New member
This might be slightly off-topic. But I just wanted to say that I try never to pay retail for steel. I have a local recycling center that has a great selection that they sell for pennies on the dollar. I am making these brake conversion brackets from some 3/8 steel that I got along with another 3 foot section of 12 inch channel for about $7. I'm sure the same steel would've cost more than $150 at a regular steel supply.
All of this for $7!
All of this for $7!
WrenchTech
New member
Well I'm learning not to trust the databases that auto parts dealers like AutoZone and Napa offer to the public. It seems pretty clear that there are different rotors on the GT mustang and the cobra, but everything I was seeing yesterday said they shared the same caliper. Something motivated me to look at rock auto's catalog and I am glad I did. It seems there are different calipers for these different applications. I have been thinking I needed to use the caliper from the GT, but it is a really tight fit on the Toyota rotor. The cobra has a thicker rotor and now I know it probably has a caliper more suited to that application. The calipers looks very similar and the mounting surfaces do too, but I can't really tell from these pictures if the cobra caliber has a wider slot for the rotor. At first I thought it did but can't really be sure from the pictures The rock auto catalog also shows that these two different calipers use the same 2.5 inch piston and rebuild kit/seals. This is got me wondering if the calipers are the same and only the bracket is different. So tomorrow I'm off to a local wrecking yard that has the cobra calipers.
GT
Cobra
A nearby wrecking yard also has a pair of 1992 Toyota Celica ST seats, trim code FW10, that I use in my first-generation 4runner. My driver's seat is getting kind of tattered, so I'm going to go take a look at those. I first used those seats in my 1984 Xtra Cab. I think they look fantastic and they are great match for the gray interiors that were used in that era, and if you are a skinny guy like me, they are great fit.
GT
Cobra
A nearby wrecking yard also has a pair of 1992 Toyota Celica ST seats, trim code FW10, that I use in my first-generation 4runner. My driver's seat is getting kind of tattered, so I'm going to go take a look at those. I first used those seats in my 1984 Xtra Cab. I think they look fantastic and they are great match for the gray interiors that were used in that era, and if you are a skinny guy like me, they are great fit.
Last edited:
