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johnc

Subaru WRX STi R180 Side Axles

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Next week my machinist will be cutting one pair of side axles (stub axles) that will fit in the 27 spline 2004/2005 Subaru WRX STi R180 rear CLSDs and 2006 VLSD. The flange end of the these side shafts will bolt up to the stock 240Z halfshafts. This pair is the prototype and will be made from 4140, heat treated, etc.

 

What I need is someone who can test these for me starting in mid-June. That means you must have the Subaru diff in hand (or can get one quickly) and have a running, driving, reliable car that can put some street and track miles on it in a short time. That's a tall order but you'll get to keep these side axles if you follow through and send me feedback, pictures, and measurements.

Edited by johnc
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Next week my machinist will be cutting one pair of side axles (stub axles) that will fit in the 27 spline 2004/2005 Subaru WRX STi R180 rear CLSDs and 2006 VLSD. The flange end of the these side shafts will bolt up to the stock 240Z halfshafts. This pair is the prototype and will be made from 4140, heat treated, etc.

 

What I need is someone who can test these for me starting in mid-June. That means you must have the Subaru diff in hand (or can get one quickly) and have a running, driving, reliable car that can put some street and track miles on it in a short time. That's a tall order but you'll get to keep these side axles if you follow through and send me feedback, pictures, and measurements.

Just a thought, but you might try asking that guy that did the write up for the Subaru R180 conversion, since he would probably have most of those parts on hand, if not all of them.

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Sounds good, I'd be very interested, I will be running a mild 327 sbc though so I wonder if the halfshafts and diff will hold up. In saying that the PO ran the standard halfshafts and r180 for 18 years without a problem:confused:

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We might be able to help with the testing. We can drive to you shop to take care of whatever needs to be taken care of. Our 73 240z is drivable and has had some track time as well as still being street legal. We have a Subaru CLSD 27 spline.

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Next week my machinist will be cutting one pair of side axles (stub axles) that will fit in the 27 spline 2004/2005 Subaru WRX STi R180 rear CLSDs and 2006 VLSD. The flange end of the these side shafts will bolt up to the stock 240Z halfshafts. This pair is the prototype and will be made from 4140, heat treated, etc.

 

What I need is someone who can test these for me starting in mid-June. That means you must have the Subaru diff in hand (or can get one quickly) and have a running, driving, reliable car that can put some street and track miles on it in a short time. That's a tall order but you'll get to keep these side axles if you follow through and send me feedback, pictures, and measurements.

 

John , i have got a Subaru 180 diff 4.44 ratio with a gear type ( no plates ) lsd specialist ?? told me that it should be a viscous but its definetly not .

I want to use inner CV from Subaru and i made new flanges for the outside to fit 110 diameter Lobro CV without any spacer , i bought the diff but i still not know of witch type and year Subaru it is ,

Regards Adrian , www.va-motorsport.com

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I don't know what Subaru sold in Europe or Japan. Here in the US they used a CLSD in 2004 and 2005 and a VLSD in 2006 on the STi. The gear ratios are 3:54 and 3:90. Even then I might have those figures wrong.

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I don't know what Subaru sold in Europe or Japan. Here in the US they used a CLSD in 2004 and 2005 and a VLSD in 2006 on the STi. The gear ratios are 3:54 and 3:90. Even then I might have those figures wrong.

 

Hi John, the 2006 STI should be CLSD also (like the 04' and 05').

 

3.54 ratios are in the 2006 and 2007 STI.

3.90 ratios are in the 2004, 2005, and 2008 STI.

Torsen LSDs came in the 2007 and 2008 STI.

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I don't know what Subaru sold in Europe or Japan. Here in the US they used a CLSD in 2004 and 2005 and a VLSD in 2006 on the STi. The gear ratios are 3:54 and 3:90. Even then I might have those figures wrong.

 

John , i found out about the lsd , its a Torsen T2 , the 4.44 is right , you are right about they probably do not have it in the US ,

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Got the rough machined prototype and I've welded the shaft to the flange. Next step is more machining, heat treating, final machining, broaching, and case-carburizing. Material is 9310 which is typical for carburized gears.

 

ProtoType-1.jpg

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Seems to me, using that material, even with half-assed heat treatment, the weld is going to be the weak spot, not the splines. How are you addressing that? (seriously interested, since I am studying to be a metallurgical engineer)

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Seems to me, using that material, even with half-assed heat treatment, the weld is going to be the weak spot, not the splines. How are you addressing that? (seriously interested, since I am studying to be a metallurgical engineer)

 

Through design, process, and testing.

 

In any manufactured part there is going to be a weak spot. The factory side axles have the flange fusion welded to the axle the same as the factory stub axles.

 

There are two welds holding the flange onto the axles and both have .063" 60 degree bevels machined into the welded joint. ER70S-2 filler is used and the parts are TIG welded. We did not use ER80 filler because of the post welding carburizing. The additional carbon content of ER80 would have made the surface carbon content at the weld too high after carburizing.

 

We're designing for a 2,500 lb. 240Z making about 275 ft. lbs. of torque running 275 width wheels. Which is almost exactly what the Rusty Old Datsun was back when I ran R180s behind it with Quaife diffs and stock side axles.

Edited by johnc

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