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SVX lsd in a brat?


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As lsd's a bit thin on ground here in UK have found a SVX diff IM asuming this has a lsd? will diff (what ratio would this diff be) or will the lsd parts fit the crownwheel of my brat. doing a thread search differences are at the driveshafts. male or female at a certain year if im correct. & a certain amount of clearancing may be required round the casing.

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I just went throught this recently.

 

Yes, all AWD, SVXs' had a VLSD rear in 3.54

 

And yes, it can work. You need a set of SVX inner cups, swap them onto the end of the brat axles. You may need a donor set of XT6 axles to get the correct inner cage. I haven't done it, but I've talked to enough people on XT6.net to know it can work.

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Cheers for inputs.

done a bit of thread search bit confusing some say can swap diff cages about swap crownwheel ect. some say cant.

Did think as a welder if all else fails could make up hybrid drive shafts brat outer svx inner:)

vlsd would probably be kinder on gearbox shafts ect than welded as my origional thoughts, or if cant find a lsd, as will be a rwd road toy 99% of the time.

so ratio would be 3.54 will have to see what price I can get it for & see if can get the inner cups.

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Cheers for inputs.

done a bit of thread search bit confusing some say can swap diff cages about swap crownwheel ect. some say cant.

Did think as a welder if all else fails could make up hybrid drive shafts brat outer svx inner:)

vlsd would probably be kinder on gearbox shafts ect than welded as my origional thoughts, or if cant find a lsd, as will be a rwd road toy 99% of the time.

so ratio would be 3.54 will have to see what price I can get it for & see if can get the inner cups.

 

Swap ring gears and it can be any ratio you want. As long as it's 3.7, 3.9, 4.11, or 4.44

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VLSD might as well be an open diff as far as the Brat is concerned. They only lock with enough friction to change the state of the fluid in the viscous coupler. That means they lock in high-speed cornering applications. They are open for slow speed manuevering. It's a street racing type of limited slip device, not a clutch type. It will buy you nothing in exchange for a lot of work.

 

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I can also tell you that the 4 speed rear output shift dog will not handle RWD with any kind of severe use. It's not designed for this purpose and it will shred eventually. Subaru transaxles are not built for RWD only applications - more than one person has found this out the hard way when that shift dog tears itself apart. Any kind of locker or limited slip device will only make this worse as it will put a ton of strain on the rear output transfer gears when the wheels lock together in a turn.

 

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VLSD might as well be an open diff as far as the Brat is concerned. They only lock with enough friction to change the state of the fluid in the viscous coupler. That means they lock in high-speed cornering applications. They are open for slow speed manuevering. It's a street racing type of limited slip device, not a clutch type. It will buy you nothing in exchange for a lot of work.

 

GD

 

No offense man, please.

 

But have you ever actually used one to wheel with?

 

Speaking strickly of how the center , AWD VLSD performs as compared to the *locked* center of the older 4wd. I can say that the AWD VLSD is great. We have wheeled the snot out of our 90 Legacy after lifting, and it is without a doubt a solid performer off-road.

 

Now this is a bit of apples and oranges cause the thread is about REAR LSDs. But really it's the same principles.

 

People said the Vlsd centers sucked and I have seen for myself that isn't true. I can only speculate but I have a feeling there is a good reason Subaru moved away from Clutch pack type to viscous. BECAUSE IT WORKS!

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I can also tell you that the 4 speed rear output shift dog will not handle RWD with any kind of severe use. It's not designed for this purpose and it will shred eventually. Subaru transaxles are not built for RWD only applications - more than one person has found this out the hard way when that shift dog tears itself apart. Any kind of locker or limited slip device will only make this worse as it will put a ton of strain on the rear output transfer gears when the wheels lock together in a turn.

 

GD

 

This is the best perspective on this thread so far.

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Oooops! didn't expect a fight:eek: ........dont want to pour petrol on on the fire but.........vlsd works on viscosity of oil, so would a different viscosity oil would make it lock sooner?

 

Im testing the water here I see some of yourselves have rwd the awd setup. will my brat running gear be on borrowed time if Iturn it into a lowered sideways rwd plaything......or before I get too involved in mods I have in my head, and bearing in mind here in UK early uprated parts from xt ect are like hens teath but Impreza parts common am I better to rebody a wrx into the brat.:confused:

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yea cheers bratman, sent him a mail hopefully hes online sometime. is this slamming it in the weeds rump roast out rwd just a UK thing/illness:lol:

 

Well honestly I would say that 95% of us need the 4wd and the clearance for where we live. But it's cool and unique so go for it!

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pretty sure the LSD chunk in the SVX is different like where the axle stubs are. Axles on the SVX are a total alien they are bigger, splines different/reversed, different spline count on inputs etc. I might be wrong.

 

I know of a couple people that have figured out how to do it but I'm not giving any names since its their discovery and not mine...

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No offense man, please.

 

None taken of course. :)

 

But have you ever actually used one to wheel with?

 

I have not wheeled with a VLSD. I have wheeled with welded (currently), and in the past with a clutch style LSD - both in the rear.

 

I also have a VLSD on my 91 SS. It rocks for high speed cornering.

 

As far as off-road, the Welded rear is far superior to anything else I've used.

 

Having the VLSD in the *center* may be the primary reason behind the AWD performing as well as it does. I have seen them perform well also and I tend to think it's about the ability to transfer power between front and rear wheels without causing the non-powered wheel to dig a big hole under itself. Taken that way it's actually the ability for the VLSD to *slip* rather than to lock-up that accounts for the difference in the AWD systems vs. the 4WD.

 

Unfortunately that affect doesn't really extend to a rear mounted VLSD.

 

As you say there's a reason Subaru went to the VC's on the center and the AWD system - there's also a reason that you only see rear VLSD's on WRX's, SVX's, and my 91 SS. They are primarly street or high speed machines.

 

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will my brat running gear be on borrowed time if Iturn it into a lowered sideways rwd plaything......

 

am I better to rebody a wrx into the brat.:confused:

 

Yes on both accounts. The part-time 4WD transmissions are designed to only engage the rear output for *added* traction. The transfer gear's and shift dog that engages the rear drive shaft are not designed to drive the whole weight of the vehicle. This is one of the problems with using them to drive a transfer case on heavily lifted rigs and it's also what prevents people from making drift cars using them. It will run for a while, but you will shred it in a few thousand miles - you might get 10,000 on a gear-set/shift dog.

 

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lots of debate of whether it will work or not. but it seems the only one of those posts by someone who's tried includes pictures of it done:

http://subaruxt.com/forum/viewtopic.php?f=1&t=2089&st=0&sk=t&sd=a&start=90

 

 

SVX uses an r160 VLSD. I agree, I do prefer the clutch-type, but if that isn't available, a VLSD > open every day of the week. and a welded diff isn't for everyone either.

 

you'll need to swap the SVX inner DOJ cups onto the EA shafts. I've heard the XT6 shafts are larger in diameter than other EAs, so in an EA81, you might need custom races. but even that is peanuts compared to trying to get your hands on an EA82 LSD.

 

 

I plan on putting an SVX rear LSD in one of my EAs this spring. I'll include pics of it as well.

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Unfortunately that affect doesn't really extend to a rear mounted VLSD.

 

As you say there's a reason Subaru went to the VC's on the center and the AWD system - there's also a reason that you only see rear VLSD's on WRX's, SVX's, and my 91 SS. They are primarly street or high speed machines.

 

GD

 

Some Outbacks and I think Forresters have a VLSD rear.

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