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Rear Diff Conversion on a Brat, Help


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Need some help on rear diff conversion, most swaps have been done using the xt6 parts and I cant get a hold of any, is there another way to do the conversion?

 

Currently I have STi V7 Engine, 6 Speed gearbox with dccd and rear diff, drive shafts and hubs.

 

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If you have all the parts that go with the engine and trans., then I would just do a custom fit job. You will have to get the driveline cut down to size but at least you know everything is matched together. I had a custom driveline made for my Brat, it was $135. I went to the shop and the guy showed me where to measure from and I did twice to make sure I had the same measurement once everything was in place and the driveline fit perfect. 

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XT6 parts change nothing as far as the diff is concerned. They are necessary for the 5-lug conversion.

 

You're trying to put the r180 into your car? Boy, if only someone had just put in a bunch of time compiling a FAQ for the Retrofitting section that might have that exact information  ;)

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What I did on my Brat was kept the original diff but changed it out with a LSD from an Rx, plus it keeps the stock axles and then you don't have to make one every time you need one.

 

I want to use the 5 lug as well ...

 

Theres always a nother way what exsacly are you tryin to do what parts arent working

 

I want to push in the Ej207 V7 Engine, Transmission, Rear Diff and 4 pot calipers into the Brat. The rear diff swap with the 2 pot calipers is what i need help on mainly.

 

If you have all the parts that go with the engine and trans., then I would just do a custom fit job. You will have to get the driveline cut down to size but at least you know everything is matched together. I had a custom driveline made for my Brat, it was $135. I went to the shop and the guy showed me where to measure from and I did twice to make sure I had the same measurement once everything was in place and the driveline fit perfect. 

 

The custom fit is what i need guide lines on, fitting the entire rear cross member is what i do not even want to think about.

 

XT6 parts change nothing as far as the diff is concerned. They are necessary for the 5-lug conversion.

 

You're trying to put the r180 into your car? Boy, if only someone had just put in a bunch of time compiling a FAQ for the Retrofitting section that might have that exact information  ;)

 

Exactly! have been searching, getting no where...

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My Brat is 5 lug. I grabbed some rear XT6 hubs bran new when you could get them and they bolt right on. 

Basically, you just have to get under there and start seeing what you have to do to use the newer stuff you have. It isn't as hard as some people make it out to be. I would strip all the old stuff out of the way and then get the rear diff on a jack and put her up there and start looking to see what it needs and start making it. 

Everybody was telling me things wouldn't fit on my Brat and it did and I made it work. Just don't be afraid, just take your time and do it right and make it strong. Basically just mimic what it came out of and then modify the Brat to fit that. 

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You can't do a 5 stud conversion by swapping the entire suspension without a lot of fab work.

dfoyl on here had some custom hubs made up that fits our cars which are a copy of the XT6 hubs.

Swap the diff over to your EJ type. Try to find the stub axles from a Gen 1 Legacy rear diff. Not sure if they fit the R180, as I've only ever done it with an R160, this allows you to retain your original driveshafts with the EJ diff.

Fit the 5 stud hubs & EJ backing plate (this is a bit of fiddling).

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But that is the whole problem. You can't find the hubs to do that. How much did dfoyl have to pay to get the custom hubs? 

Because it seems that is what has to happen because you can't buy them new and you have to be looking for the cars that have those hubs, xt6's, and they are hard to find too.

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Use the entire rear.end from the doner car just shorten every thing up dont try to use.whats on th3 car you will have to fab up mounts for everything just a mater of how far you are willing to go

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I was talking with a guy who is a machinist and was wondering about the hubs. I sent dfoyl a pm and I would be interested to see what someone is charging for that. I bought new 5 lug hubs from Rock Auto but I must of snagged some of the remaining ones cause I can't seem to find them anywhere. 

But from a parts stand point, amk, I would lean towards newer parts and cars so easier to attain. There is enough info on here to see what others have done and use what you can and modify to your needs. 

It makes more sense when you get the rear diff up on the jack and you can see what you need. It may be easier than it seems. I know when I did my Brat it was. Great bunch of guys on here, so don't be afraid to ask questions. I get answers all the time. 

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The first run of replica hubs was like $200 USD for a pair. With those (or XT6) the EJ brakes will bolt up the trailing arms. Sourcing those is the hard part.

 

 

The diff alone is easy, the mounts bolt right up, driveshaft bolts right up. There are several options to attach the EA81 axles to the EJ diff.

 

There are several options for suspension that bolts right up.

 

This stuff has all been done and documented.

 

 

 

EJ Modified-MacPherson rear suspension has been put in a Brat (IIRC it was in the UK, so I think they just call them a pickup...). It looked like a completely nightmare. You have to make mounts for the suspension crossmember, trailing arms, and strut tops, all of which need to be positioned perfectly, and build strut towers. In a Brat, these strut towers are visible in the bed, so that may be a concern depending on the project. At stockish height, the crossmember and gas tank interfere.

 

I'm not saying it can't be done, but it's the classic reinventing of the wheel. It's a massive amount of work to avoid buying a pair of hubs (I know they're getting rare, but it's still possible), for negligible gains. Yes, the old EA rear suspension geometry isn't ideal for true performance, but if you're nitpicking that far, the Brat probably isn't your best starting point (dreadful aero and weight distribution, although it's possible to get around that). If you really are looking for better geometry, there are much better/easier ways to get it. The '08+ Impreza, '09+ Forester and '10+ Leg/Outback rear suspension comes to mind, it's a complete multilink unit. You'll probably still have to modify the gas tank, but only 4 big bolts to hold the entire rear suspension on, and the geometry all stays the same. And the shock is mounted much further down, so you don't have to cut up the body to make strut towers.

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That is some good points Numbchux. I just put some Rancho shocks on my Brat and it has a 4 inch lift and it is fine. I have the 5 lug hubs from an Xt6 on the rear. My front has all Legacy Turbo front clip with the entire suspension. I was thinking of weighing the front of the Brat and then the rear and then  making a ballast weight for the bed across the top of the tires to equal the difference. 

 

But it is true about performance. If I wanted more, I would get a newer Subie. But my Brat is going to be D.D. with some kick under the hood. Nothing crazy. Subaru has come a long ways since the 80's for technology and you are right, you don't want to push the older cars too much, otherwise you are basically rebuilding the whole car to handle your changes. 

 

Oh and hubs are $320 shipped from Aussie.

Edited by Naked Buell
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