Aluminum Rear Disc Brake Bracket (1 Viewer)

[oldIron]

Since I am doing this to a 40 I put it in this section. I downloaded the PDF Rear Disc Bracket, plus I have a set as a template. I have a feind who is a machinist and did my rotors for me. I showed him the Rear Disc Bracket PDF and asked him what he thought. He said that cutting the bracket would be easy but wondered how it would be if he machined it out of aluminum and put some reinforcement out of steel pressed into larger diam holes at all the mounting points. My fear with aluminum is the overall strength of it as compared to the steel bracket and considering that these are the rear brakes, I am not certain of the potential. I thought I would throw this out to all of you guys and gals who may have some more insight here.

Please enlighten me...

 

[tlcruiser66]

Should be alright... depending on how it's constructed (thickness, bracing, material). You might also want to think about shot peening the material to pre-stress it. Keep us informed on the progress.

Kevin

 

[oldIron]

Thanks tlcruiser66 any one else?

 

[mcanuel]

where are these disc templates on the site?

 

[dgangle]

the file floating around is for the disc bracket. I build a lot of stuff but as cheap as these are and as many available sources I can't imagine messing with fabbing them. On the rotors you just open up the centers on a lathe to fit the stock semi-floating rear axle.

 

[hicruise55]

"Please excuse my ignorance... but why would you WANT to use aluminum?

To me, brakes seem a little to critical to risk experiment with different forms of aluminum brackets "

X2? no need to overthink... no benefit that I see? Am i wrong???

 

[4x4Poet]

Alum would provide less sprung weight at the expense of strength against stress breaking/cracking. Note how aluminum trailers for heavy use, like car haulers, need careful engineering to include the use of well placed bracing to keep the trailer frame from eventually cracking or breaking under load while stressed by road travel.

An RDB bracket is a much smaller engineering issue to solve. I'd guess a certain thickness alum would address all concerns, but would it weigh less than proven, easily obtained, steel RDB brackets?

Achieving less unsprung weight at the axle ends is definitely beneficial to compensate for the extra weight (over OEM) of big tires, but I'd hope whoever uses alum RDB brackets really knows what their doing.

 

[Mark W]

sprung/unsprung weight really is not worth worrying about in an FJ40. It handles like a buckboard wagon anyway. I would not even consider the effort or expense... no point in reinventing the wheel for something that will make no discernable difference.


Mark...

 

[ducktapeguy]

New brake ideas aren't something I'd want to be the guinea pig for. I'm sure it could be made to work, but I don't really see any advantage to it.

For one thing, aluminum has a fatigue limit that you don't have to worry about with steel. Plus, aluminum starts losing it's strength very quickly at moderately high temperatures. I don't know the exact numbers, but I think it's something like 50% reduction at 600F. Even though I doubt the brackets will ever see that much heat, why take a chance. Any potential weight savings from the different material would probably be offset by the extra thickness needed to equal the strength of a steel bracket, not that you'd be able to feel the difference either way.

 

[Downey]

We never made Landcruiser rear disc brake brackets out of aluminum, but 1,000 years ago we did make some Toyota 4WD brackets out of aluminum. One customer clobbered his rear end on a tree branch submerger in deep wet mud and broke the aluminum bracket while ripping the caliper off the rear end. We then decieded to stick with steel brackets!!!