[FuJi K]

I just finished swapping in my 02 Forester 4EAT a VTD multi plate center diff from a 02 4EAT WRX donor.

Initial impressions.
The characteristics remind me of the 5spd AWD setup. The reason I say this is because of the wandering it has up front when you apply throttle. The VLSD center diff on the 5spds aren't the best in keeping the front and rear tight. The lockup is "enough" but not enough in my opinion. So in comparison without any hydraulic pressure utilizing the multi plate clutches of the VTD differential, it operates as an open differential.

The clutch plates are 2 less than your transfer clutch units (3 vs 5). I hope that the differential action does somewhat help. I will have to test how well it holds up in dirt/rock climbing situations where wheel slippage is minimized.

Now it's hard to tell the rear biased because I have a welded differential in the rear. It's also snowing in MN right now. The rear end does step out when I give it throttle, however the welded diff plays a big part in that. I would say it is feeding as much as it can since the rear does come out when I don't have the clutch plates engaged via my switch.

Enjoy!

 

[FuJi K]

Here's a burnout test

 

[jf1sf5]

I don't understand the mod you did as I have a 5MT. What are the differences between both 4EAT's ? Wouldn't it be easier to put a switch to bias the Foresters 4EAT and lock it 50/50 ?

 

[FuJi K]

The Forester 4eat uses a transfer clutch to drive the rear. The WRX 4eat uses a planetary gear center diff with a torque split off 45:55 and transfer clutch to lockup for maximum front/rear traction. I like the center diff more than the transfer clutches driving the rear. This functions just like the DCCD. I wished it was standard on all Subaru manuals and autos. The VLSD sucks.

Here's a test on frozen dirt going up a mound

 

[Canonshooter]

Good videos showing the role of the locking clutch pack in the VTD center differential. If only they made a manually locking rear diff....

Based on my experience of going to a VTD center differential this past year, the biggest advantage IMO is dry road performance. I had always found the TCU-controlled MPT transfer case that came standard in my '07 XT Ltd. perfectly adequate for snow and light off-roading.

I too removed control of the VTD locking clutch pack from the TCU and set up a switch on my shifter to lock it as needed.

 

[FuJi K]

^^^^
I was reading through your swap and the limited info out before doing mine. Thank you for providing some details on your setup!

While the OEM transfer clutch was nice, it was slipping on me when I took it off roading in TX with the welded rear. It was holding but not enough when going up hill. The rear relied on the plates friction to push the car forward. Then again the tranny also had 200k miles.

Here the original transfer clutch doing work.

 

[jf1sf5]

On the last video with the OEM transfer clutch pack, did you have the locking modification ? Or is everything OEM except welded rear diff ?

 

[FuJi K]

I had the locking mod, but the tranny had like 200k miles. A bit worn on the transfer clutches perhaps.
I'll take a picture of them later.

 

[FuJi K]

Here are the plates from my 02 Fozzy's transfer clutch. There are some material on the plates. Seems the plates got glazed from the clutch material.

 

[FuJi K]

A new video running through packed snow. Using light throttle to minimize excessive wheel spin.

 

[FuJi K]

Here are the VTD center diffs plates

 

[FuJi K]

some more

 

[FuJi K]

Added 1 more disc and plate. Now 4 instead of 3 discs.

 

[jf1sf5]

How were you able to add 1 disc ? Did you put narrower bearings ?

 

[FuJi K]

I pulled out one of the thick rings. I picked up another VTD tranny from a baja XT and used a disc/plate from that.

How were you able to add 1 disc ? Did you put narrower bearings ?

 

[Type2]

In case anyone is curious, here is a video of my VTD center diff. I never installed it and going 6mt. Haven't decided what to do with it.

https://www.youtube.com/watch?v=_qdTW5w-RWc&feature=youtu.be

Also, my short thread has some pictures:
http://www.subaruforester.org/vbulletin/f89/mpt-vtd-swap-2004-fxt-423810/

 

[jf1sf5]

Thanks for the explanations, very clear.

A friend will probably do this swap sooner or later...

 

[lame_dc]

I just finished swapping in my 02 Forester 4EAT a VTD multi plate center diff from a 02 4EAT WRX donor.

Initial impressions.
The characteristics remind me of the 5spd AWD setup. The reason I say this is because of the wandering it has up front when you apply throttle. The VLSD center diff on the 5spds aren't the best in keeping the front and rear tight. The lockup is "enough" but not enough in my opinion. So in comparison without any hydraulic pressure utilizing the multi plate clutches of the VTD differential, it operates as an open differential.

The clutch plates are 2 less than your transfer clutch units (3 vs 5). I hope that the differential action does somewhat help. I will have to test how well it holds up in dirt/rock climbing situations where wheel slippage is minimized.

Now it's hard to tell the rear biased because I have a welded differential in the rear. It's also snowing in MN right now. The rear end does step out when I give it throttle, however the welded diff plays a big part in that. I would say it is feeding as much as it can since the rear does come out when I don't have the clutch plates engaged via my switch.

Enjoy!

Do you have any idea of how hard this would be to do for an 05 Forester xt auto I really want the 45/55 split and I also want to push 370-400awhp with ipt built kit I have no idea what wiring goes into making this work at all