Starting a new project...Subaru STI Differential swap into my Z

[Zedyone_kenobi]

UPDATE:

Diff came in Saturday and Half shafts Friday.

Huzzah! I ordered a one ton arbor press from Harbor Fright… So we will get to work soon on cleaning polishing and painting.

[Zedyone_kenobi]

parts are in. Just waiting on my press!

[madkaw]

Press is for?

[Zedyone_kenobi]

Studs that go into the half shafts.

[madkaw]

I guess i only remember cleaning up the old ones and throwing them in the freezer! I guess they are a 'press fit', but just a tight tolerance.

The only issue I had with my axles was that the ID machined on the new axle that mates to the raised circle on the DS did not match. I coudn't get the DS to fit onto the new stub axle. After measuring I found that the new axle was under machined by .003, so I had to take them to get cut. It should be a snug fit, but make sure you really clean off your old DS in this area well.

I haven't read of anyone else having this issue, so it might have slipped thru QC.

[Zed Head]

Depending on the fit, you might use a stack of big washers and the nut to pull the stud in to place. Check the flange fit first though, re madkaw's post.

Did you get the studs from your local dealer or Courtesy?

[Zedyone_kenobi]

No, I have a spare R180 Diff in my storage unit I plan to take the studs off. I will leave this Diff untouched as it came with the car. So I will rob the studs from that diff. Figured I would save a few bucks doing it that way.

I have been wanting an arbor press for a while anyway, it can have so many uses. So I figured why not pick one up.

[beermanpete]

We reused the factory bolts as well. They do fit tight into the flange. There is no chamfer on the flange and it raised burrs when we installed the bolts. You may want to lightly chamfer the back side of the holes in the flanges. Freezing the bolts as Madkaw suggested will help as well.

[Carl Beck]

Zedy..

Looks like you are making great progress as usual.

Maybe I missed it over the course of this discussion - but what type of LSD is in that Subi unit?

Dave - I've had a Torsen/Gleason unit in my 72 for decades now. BSR set it up for me in the mid 70's with 4.11's - the only time it "clunks" is when I backup and at the same time turn. I am told this is common with that unit, as the mechanical parts unload in that situation.. Other than that it has been indestructible and never clunks moving forward - or in reverse if I'm going straight back.

BTW - When I swapped out the L24 for an L28 - I found that the 4.11 was unnecessarily low - the L28 has so much more torque - a 3.7 would have been better for my use..

FWIW,

Carl B.

[madkaw]

Carl,

3.9 ratio:

2004, 2005, 2008

3.54 ratio:

2006, 2007

CLSD:

2004, 2005, 2006

Torsen LSD:

2007, 2008

I'm running the 3.90. Pretty damn quiet. Sometimes pulling into my garage, which is steep, I hear and feel a studder and I think thats the LSD, but can't swear to it.

[Zedyone_kenobi]

THanks madkaw, I was about to look up what kind of LSD is in the 2004 unit

[Zedyone_kenobi]

Took the day off to have some free time on what must be the most lovely day of the year so far in the Houston Area. Fired a pot of coffee, turned on my favorite country station, and slowly began taking the factory diff out of the car. Well less than 2 hours later… I was done.

I sprayed some simple green on the OEM diff and then drug it out into the sun to compare it to the STI diff. I would wager more people will want to see the comparison of the two… so without further ado:

Next think want to do is pull off the rear cover and the side covers off the STI diff and give them a good cleaning. The rubber seals where the output shafts contacts look to be a bit rough. I may have to go by Subaru parts to get more rubber seals so they do not leak. They may be the same as the Datsun ones, I do not know until I pull the sides off.

Will probably get new bolts or send mine off to get cleaned and plated. Not sure yet. Everything unbolted perfectly fine. I had to cut the old Diff strap off to get it out as my exhaust was too big and would not let the diff crossmember move out of the way. But this may give me a chance to finally use the RT Diff mount I have had for 2 years.

Well that is enough work for now. I have to start looking to get parts cleaned. Then I can make a run to the storage unit and get my spare diff and pull the half shafts.

Anybody have any advice on puling the OEM halfshafts out?