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Rear Disc Brake Difference 2WD vs 4WD

Featured Replies

belacane is selling a set of disc brakes from an XT. Does not know if they were from 2 or 4WD.

 

What is the difference in the backing plate, specifically the center hole from 2 vs 4WD, the set she has, the center hole is approximately 2.5"? I looked under my Brat, obviously as you probably know that does no good.

 

Any other differences between the 2 versions?

 

Any thoughts would be greatly appreciated.

 

Thanks in advance.

  • Author

Can you be more specific, different in what way?

 

So that we can figure out if they will fit my Brat.

 

Thanks

The 2WD Disc Rotors mounts on a Dead Spindle, while the 4WD ones has the Constant Velocity Joints' (Axle) Shaft, so they're not interchangeable; but the Caliper shall be the Same.

 

Kind Regards.

About this: 

 

... if they will fit my Brat...

 

The EA82 Rear Brake Stuff will not Retrofit "Easily" on EA81 Chassis, things aren't Compatible.

 

So, if you want to do such retrofitting, you must do some Mods and / or Suspension Swap...

 

Kind Regards.

Look for splines inside the middle of the hub. Those are 4wd ones. If there's no spline, they're the FWD version.

The centre hole on backing plates on the FWD verison is also smaller.

 

The discs & calipers are the same.

 

First I've heard of needing mods or suspension swap? The brake lines from the car to the caliper need to be changed and fixed to the arm, but I've never heard of anything else needing to be done. Interested to find out.

  • Author

About this: 

 

 

The EA82 Rear Brake Stuff will not Retrofit "Easily" .......on EA81 Chassis.....???

I have been under the impression that my 86 Brat fell into the EA82 chassis with an EA81 Engine.

 

:confused:  Feel free to set me straight on this one..anyone :mellow: .

 

Thanks again.

 

I certainly do  :wub:  :wub:  :wub:  :wub:  :wub:  this forum. :)  :)  :)  :)

...they bolt straight on once you fight the drums off :) ...

 

Ooops! ... Brainfart.

 

I Misunderstood somehow that he wanted to convert the Rear Axle from 2WD to 4WD... 

 

My mistake, Sorry...

 

Kind Regards.

I have been under the impression that my 86 Brat fell into the EA82 chassis with an EA81 Engine.

 

:confused: Feel free to set me straight on this one..anyone :mellow: .

 

Thanks again.

 

I certainly do :wub::wub::wub::wub::wub: this forum. :):):):)

The rear brakes will bolt on but your 86 brat is an ea81 chassis.

The rear disc bracking plate bolts onto any ea81 and ea82 trailing arm the same. The rotors are the same, but the hub is different for 2wd and 4wd. The same rotor would bolt onto either hub.

 

There are about 3 different styles of caliper depending on year and model, but they will all interchange with eachother for physical fit with the slide pins and caliper brackets to backing plate.

 

Another option should you not find parts, is swapping on larger ea82 rear drum brake in place of ea81. Swap over the whole thing uncluding backing plate and drum.

 

Once again, a 2wd and 4wd rear drum brake is the same with the exception of the drum itself where it fits onto the spindle or axle

 

You can make it a step easier by swapping a whole ea82 trailing arm with brake directly in place of the ea81 trailing arm, if you drill out the mount holes and use the ea82 pivot bolt. (if you have a lack of sources for parts)

Edited by MilesFox

...There are about 3 different styles of caliper depending on year and model, but they will all interchange with eachother for physical fit with the slide pins and caliper brackets to backing plate...

 

Yes, to this I must add that I found a Fourth Caliper that features Rear Parking Brake,

 

and is a Direct Fit; More info on the Subject, Here:

 

~►  http://www.ultimatesubaru.org/forum/topic/129779-the-definitive-rear-e-brake-retrofit-solution/

 

Kind Regards.

The 2wd hubs are different and ride on a smaller spindle. 2wd rear disk on 2wd and 4wd rear disk on 4wd.

 

Yes the 4wd rear disk parts will bolt on your brat.

  • Author

Thanks everybody!

 

Can't wait to get them installed.

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