By definition, a mechanical device that allows a differential between the speed of two or more of its outputs can be called a differential. A viscous coupling is a type of diff just like ye olde spider gears. And apparently people have welded EJ viscous couplings before.

I looked into a driveshaft disconnect. All that would take is mailing the driveshaft and slightly over 1k to Remco, who mails it back rebuilt and with a disconnect unit, and then I have to fabricate a cable actuator. That's it. This is for a friend of mine and part of me thinks it's a cool project. The rest of me agrees it's not enough juice for the squeeze, and won't bother.

Your helicopter would pass me too. And I give about as much of a damn.

10 hours ago, Tillaru said:

By definition, a mechanical device that allows a differential between the speed of two or more of its outputs can be called a differential. A viscous coupling is a type of diff just like ye olde spider gears. And apparently people have welded EJ viscous couplings before.

You can find stupid people doing stupid things all over the internet. Doesn't mean it's a good idea. You haven't seen how these are constructed of paper thin interleaved sheet metal discs with a silicone fluid injected into the housing and the hole sealed with a ball bearing peened into it...... trust me welding this mechanism would be a disaster and the results would be awful. I'm quite sure that young Billy-Bob and his cousin Skillet have done all kinds of things with their buzz-box stick welder that shouldn't be talked about in mixed company but it doesn't make it a smart choice. 

And for the record, a Viscous Coupling is not a differential at all - it is a form of limited slip device. It doesn't allow power transfer to be differentiated between a single input and multiple outputs - it allows slippage between the input and the output. The center differential assembly in the Subaru is composed of a differential in which one of the output spider gears IS the viscous coupler. 

GD

Edited May 28, 20205 yr by GeneralDisorder

Ok, I stand corrected regarding the visco; thanks for explaining.

So, turns out that Legacy #3 is a 95, with a bunch of fresh parts, running and driving well. Opinions?

If the 95 is running well, just use that if it’s awd. 

Cheers 

Bennie

Is the 90 (the one in pieces) worth keeping for parts? I know the body and interior are different, but how many of the mechanicals are compatible?

Engines and trans are compatible. The 95 intake manifold and all electronics bolt right on top of the 90 (or 89 as you called it earlier I think....?).

If you’re willing to look into custom hubs and shafts then just bolt the Legacy engine to the Loyale trans and install it. All you need is an adapter plate which is easy and the learning curve has already been done. Convert some axles and modify the driveshaft length 

It’s a poor choice, but in those same terms,  so is every other option youre choosing. And I don’t mean that as a slight. You’re obviously working from a different set of constraints than most people would - I work differently than i did 15 years ago and so does GD - so just get, or make, an adapter plate and you’re done. Mix and match some axles, driveshaft length.

Theres no practical physical benefit for PT4WD or FWD in a Subaru unless you want to do burnouts and spin tires.  All the weight of the 4WD and rotating driveline is still there.  There’s no mileage benefit except mentally one might drive more mileage minded if they think they’re in a “higher mileage” contraption. put a FWD sticker on the instrument cluster.  

Subaru Autos that are converted to FWD see no mileage improvements or they’re very small and only in specific driving conditions.  If you want to maximize mileage dial in your tire size to driving conditions to maximize gearing.

Edited May 30, 20205 yr by idosubaru