Traction project

[Tapani]

The traction project has begun on my Toy,

The 4.444 ACT-4 tranny will be replaced by a JDM VTD setup with the stock 3.7 gearing. Hopefully the SVX torque converter will also lower my stall speed (now 3200rpm, I trust this is from a 1997 Outback). The tranny should be on its way sailing from Houston towards Finland shortly .

I bought an open 3.7 rear diff and a Quaife Torsen carrier for it. New bearings, seals and O-rings and I'll be able to put it together. The gears look very good, also the open differential looks like new, so it should be good. I will not touch the pinion at this time.

For the front I bought an Australian torque sensing diff made by Modena. Works exactly like a "true" Torsen. Both are in the attached photo.

The TCU will be based on JDM firmware, but with custom mapping to suit my turbo engine characteristics.

Sticky tires for the 2008 Sti wheels and then I should have no more traction issues . Should be fun in the snow too.

It will be two months before I receive the tranny so this is just a start.

Tapani

[icingdeath88]

Is the rear diff an R180 or R160?

[Tapani]

Hi,

It is an R160 - I don't think a 3.7 geared R180 was ever available. The smaller one should be plenty strong - especially w/o the spider gear shaft issue. The Datsun 510 crowd run quite powerful engines thru this in RWD set ups.

Br,

Tapani

[icingdeath88]

Sounds like a plan man. Any particular reason you decided to stay automatic instead of doing a manual swap?

[dragoontwo]

Originally Posted by Tapani

Hi,

It is an R160 - I don't think a 3.7 geared R180 was ever available. The smaller one should be plenty strong - especially w/o the spider gear shaft issue. The Datsun 510 crowd run quite powerful engines thru this in RWD set ups.

Br,

Tapani

I believe the older Z car series had a 3.7 R180

[Tapani]

Originally Posted by icingdeath88

Any particular reason you decided to stay automatic instead of doing a manual swap?

Yes - I really like the automatics

Maybe I'm just too lazy.... , I drive a lot and the SVX is an old skool GT, not a real sports car .

Tapani

[Tapani]

Originally Posted by dragoontwo

I believe the older Z car series had a 3.7 R180

Ok, thanks. Didn't know that. But finding one here would have been difficult.

Tapani

[icingdeath88]

Originally Posted by Tapani

Yes - I really like the automatics

Maybe I'm just too lazy.... , I drive a lot and the SVX is an old skool GT, not a real sports car .

I think my blue car would take offense to that

Well, your auto will certainly be one to be reckoned with.

[Tapani]

Progress

The rear diff is done too, I need to get another type of a dial indicator to check the front back lash thru the drain plug hole prior to final assembly.

The Modena front diff fits the Phase 1 tranny w/o issues.

Tapani

[Tapani]

Like a gynecologist.... the backlash is set to 0.13mm thru the drain plug

I made a tool for the side bearing adjustment from a non-Subaru size oil filter tool.

Also checked the tooth contact pattern on the rear diff - looks very good, in the center and slightly shifted toward the toe under no load. Have to do this for the front too - later.

Br,

Tapani

[icingdeath88]

I have a curiousity. I am familiar with how anti-backlash gears work in the intake cam gears, but I don't get what you mean by setting the backlash in the diff. I am kind of starting to wish I had an extra broken trans to take apart to see how it works...

That's funny because I do have and extra broken trans.

[Tapani]

Well, there must be a backlash between the pinion and the ring gear. 0.13-0.18mm measured at the tip of the crown wheel teeth. This is set by moving the diff carrier from one side to the other by adjusting the position of the side bearings. On the front diff it's kinda funny because it is fully closed when the diff casing is installed on the tranny. Measurement must be done thru the drain plug hole - not very easy.

You also need to set the preload of the bearings - both carrier and the pinion - and set the pinion depth to achieve correct tooth contact pattern.

See the manual .

Tapani

[Tapani]

A little progress.... the old tranny is out

I take my hat off for you guys who do this alone on the drive way w/o a lift and a tranny jack. I made an adapter so the tranny can be bolted to the jack... not pretty, but solid

Kind regards from Finland,

Tapani

[Tapani]

Tranny swapped, still waiting for the rear support parts.

I took the rear diff down - the 4.444 has an lsd in it (three sets of splines inside), though it doesn't work.

That means that the RH inner CV joint has the long nose.

Is it possible to just swap the joint for an Outback one? No SVXs around to cannibalize the LH....

Has anyone ever cut the nose off and machined a groove for the C clip...? It appears to be in a wrong axial location to be used in the Torsen. Should symmetrical to the LD side.

Tapani

[Tapani]

Woohoo, the SVX moves on its own power again !

I cut the RH axle to fit the Torsen, swapped the larger SVX driveshaft flange to the 3.7 rear end, replaced the U-joints in the drive shaft and had it balanced.

The only thing still missing are the tranny rear supports.... the tail section rests against the X-member on a jack pad. Drove just a little around to check that the tranny does function (55kmiles claimed, 1995/6 JDM). So far so good. Nice shifts up to third, the stall speed is much lower than with the OB converter, immediate engagement to both R and D.

And yes, the VTD IS rear biased - with the torsen both rear wheels dig in the gravel first .

I hope the rear support arrives next week.

Br,

Tapani