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johnc

Subaru WRX STi R180 Side Axles

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RacerZ -- Have you read up on the replacement procedure for the input shaft at all? The output shafts appear as simple as using a seal puller and popping the new seals back in, but I'm concerned that the input shaft will require essentially pulling all of the guts out. Any idea? Thanks!

 

No, I haven't. My brother, beermanpete, seems to think the side seals will be as you described and that the input seal will be the same as the side seals. Pete is seldom wrong, but we haven't actually done this job yet.

 

Does anybody have any hands-on with this? Was it as easy as I think it will be?

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Removed and inspected betamotorsports' prototype WRx R180 CLSD to Z-car (adapter) axle stubs yesterday after drag racing with them this winter. Found no wear or cracks - they look as good as the day I installed them. Had no leakage around the seals - the specifications and machine work are perfect. I'll let JohnC do the official promotion for these, but I can tell you that I am very pleased with this product and I have two, equally long, black streaks leading from my driveway that attest to my enthusiasm. This is a simple, cost-effective way to make a dramatic improvement in the performance of your Z. Feel free to pm me for questions about the installation - it was really easy and I don't work on cars for a living.

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How about S302wrx john john side axles.:)

The WRX uses a 25 spline shaft and the STI uses a 27 spline shaft. This will fit on one and not the other. Hopefully it's the 27 spline version cause that's what my diffy has.

 

Do you guys want in progress pics ? The mat'l was delivered today.

Yes, I would like to watch the progress.

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John.

 

From this picture ...

 

Installed-2_thumb.jpg

 

it seems as if you took the differential flange from the stock 240Z R180 and placed it on to the STi R180 LSD unit with your modified shafts. This would seem to indicate you can use the stock driveshaft provided you have an existing R180 flange to swap over to the STi unit. Is this correct? Earlier in the thread you talked about a custom drive shaft being made. The rear cover shows the mustache bar mounting bolts are longer on the STi unit. Did you swap the differential covers or is this not necessary? They seem nearly identical aside from the bolt length.

 

I got my STi 3.9 LSD differential today ... so I am anxiously awaiting.

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That picture was from the guy doing the testing of the prototype side axles. He swapped the front pinion flange and the side axles I'm making have the 240Z halfshaft flange dimensions. The rear cover is stock STi as far as I know.

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This will fit on one and not the other. Hopefully it's the 27 spline version cause that's what my diffy has.

 

Yes, the side axles I'm making will fit the 27 spline R180 diff that comes out of the the Subaru WRX STi.

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The rear cover shows the mustache bar mounting bolts are longer on the STi unit. Did you swap the differential covers or is this not necessary? They seem nearly identical aside from the bolt length.

 

We R&R'd our stock rear-end recently to do the suspension bushings. Although we did not try to fit our STi LSD, I don't think the longer studs will be an issue.

 

It will be easy to double-nut the studs and change them out if push comes to shove.

 

Now that I think about it, our unit is missing the studs, how much longer are the STi studs vs the 240z studs?

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I've already pulled both of my 240z studs out and intend to install them in the WRX STi diff myself. Once I pull the STi studs I'll measure the exact difference for you if no one else has chimed in by then.

 

BTW -- Did you order the front cover gasket from Kragen also? I couldn't find the gasket on there, and was hoping to order all of the seals and the gasket at the same time.

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Just trying to piece together some info.. please correct me if I'm wrong

 

We will need the 27 spline differential.. which can be pulled from a

2004-2005 Subaru WRX STi - these are clutch type CLSD with a 3.9 ratio

2006 Subaru WRX STi - Viscous VLSD with a 3.54 ratio

 

shucks.. I really want a 3.54... but I want a clutch type =/

 

Is there a 3.54 CLSD option?

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Just trying to piece together some info.. please correct me if I'm wrong

 

We will need the 27 spline differential.. which can be pulled from a

2004-2005 Subaru WRX STi - these are clutch type CLSD with a 3.9 ratio

2006 Subaru WRX STi - Viscous VLSD with a 3.54 ratio

 

shucks.. I really want a 3.54... but I want a clutch type =/

 

Is there a 3.54 CLSD option?

 

You SHOULD be able to use a 115mm ring gear with this diff... so you should be able to swap out the 3.9

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I'm afraid that you guys are making this too complicated. Here is how the swap goes. Your Subaru rearend (call it whatever you like) is relatively new. The seals are probably fine. The rear cover is the same. Leave the thing alone. Pull the output flanges with a puller or two leavers (screwdrivers work). Put John's new output flanges in - light tap with hammer and block of wood. Take your Z input flange off with an impact wrench, a 27mm socket and a gear puller. Do the same with the Subaru flange. Put the Z input flange on the Subaru input shaft and torque it as best you can (spec is 125 ftlbs). Put oil and LSD lube in the Subaru differential (1 quart). Put the differential in the car and hook up the half-shafts and drive shaft with the original hardware. Go racing. The rear cover studs are longer on the Subaru diff. Swap them if you can - mine were in too tight. I left them. It made for a bit more wrestling, but I still got it in. This is a 1-day job tops - a couple of hours if you are good and have the tools I listed.

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2006 Subaru WRX STi - Viscous VLSD with a 3.54 ratio

 

shucks.. I really want a 3.54... but I want a clutch type =/

 

Is there a 3.54 CLSD option?

 

I forgot to include what the 2006 STI came with...I updated my post:

 

Just remember ratios and LSD type differ depending on the year (which may affect pricing):

 

3.9 ratio:

2004, 2005, 2008

 

3.54 ratio:

2006, 2007

 

CLSD:

2004, 2005, 2006

 

Torsen LSD:

2007, 2008

 

I'm not sure what came in 2009 and 2010 STIs (that's why I didn't list them above).

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I've already pulled both of my 240z studs out and intend to install them in the WRX STi diff myself. Once I pull the STi studs I'll measure the exact difference for you if no one else has chimed in by then.

 

BTW -- Did you order the front cover gasket from Kragen also? I couldn't find the gasket on there, and was hoping to order all of the seals and the gasket at the same time.

We haven't ordered anything yet. My brother says he will...

 

 

I'm afraid that you guys are making this too complicated. Here is how the swap goes. Your Subaru rearend (call it whatever you like) is relatively new. The seals are probably fine. The rear cover is the same. Leave the thing alone. Pull the output flanges with a puller or two leavers (screwdrivers work). Put John's new output flanges in - light tap with hammer and block of wood. Take your Z input flange off with an impact wrench, a 27mm socket and a gear puller. Do the same with the Subaru flange. Put the Z input flange on the Subaru input shaft and torque it as best you can (spec is 125 ftlbs). Put oil and LSD lube in the Subaru differential (1 quart). Put the differential in the car and hook up the half-shafts and drive shaft with the original hardware. Go racing. The rear cover studs are longer on the Subaru diff. Swap them if you can - mine were in too tight. I left them. It made for a bit more wrestling, but I still got it in. This is a 1-day job tops - a couple of hours if you are good and have the tools I listed.

That's pretty much what I figured. My brother and I have a different view here. I say it's new enough that the seals are probably good.

He says,

1) It's too much trouble to remove the diffy if the seals fail shortly.

2) Everything else we thought we could get away without replacing has been wrong. (We did not replace the diffy mount when we did the suspension bushings and it failed before we got to the sidewalk. LMAO it was only 40 years old.)

3) Since it's only $40 bucks, let's do it and be done.

 

I don't disagree with his logic, but...

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stubaxles001.jpg

O.K. here ya go. The slugs ready to go to the lathe.

stubaxles002.jpg

17 Lbs to start.

stubaxles005.jpg

Making chips.

stubaxles006.jpg

stubaxles007.jpg

A little code for you techie types.

 

I'll be sending them off to H.T. next week. Then a little more lathe work and spline cut. then off to beta motorsports for shipping to you guys.

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I'm afraid that you guys are making this too complicated. Here is how the swap goes. Your Subaru rearend (call it whatever you like) is relatively new. The seals are probably fine. The rear cover is the same. Leave the thing alone. Pull the output flanges with a puller or two leavers (screwdrivers work). Put John's new output flanges in - light tap with hammer and block of wood. Take your Z input flange off with an impact wrench, a 27mm socket and a gear puller. Do the same with the Subaru flange. Put the Z input flange on the Subaru input shaft and torque it as best you can (spec is 125 ftlbs). Put oil and LSD lube in the Subaru differential (1 quart). Put the differential in the car and hook up the half-shafts and drive shaft with the original hardware. Go racing. The rear cover studs are longer on the Subaru diff. Swap them if you can - mine were in too tight. I left them. It made for a bit more wrestling, but I still got it in. This is a 1-day job tops - a couple of hours if you are good and have the tools I listed.

 

You deserve something for that post! To the point and simple. It was pretty much what I initially suspected, but this thread and the endless dialogue made me start believing there was going to be more involved in the swap.

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