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Flip the entire transaxle for rear engine vehicle? I searched.


300td4x4
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I searched but did not see this idea discussed. I am wondering if anyone has considered flipping an entire Subaru transaxle for use in a rear engine vehicle? I think this would only be possible with a manual.

 

I don't think the engine would bolt up with it being right side up. So how about flipping the engine, too? Perhaps the cylinder heads could then be flipped back over so the intake is still on the top and the exhaust on the bottom? Obviously something would have to be done about the oil pickup and sump.

 

Any ideas? If this has already been discussed I apologize.

 

BTW, my intention would be to retain AWD, using a flipped Subaru differential in the front. I would want to use this in a VW like a Squareback or maybe a Bus.

 

Brian

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ShawnW I think you are confusing rear engine with mid engine.

 

theres no way to make the subaru transaxle work for rear engine as in behind the rear wheels. In vw rear-engine transmissions the pinion is centered and the diff can be simply flipped around to run in the opposite direction. Not possible in sube trannys. Rotating the engine upside down wouldnt change anything, think about it ;) Rotating the whole tranny upside down would change the direction, but look at the shape of a subaru tranny and you'll see that youd be dragging the top of the tranny on the ground.

 

Maybe you could find a porsche carrera 4wd tranny or vw synchro van running gear. Perhaps you could figure out how to run the subaru engine in reverse rotation, but then you would be running on the coast side of the ring and pinion which may or may not be an issue.

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Two problems come to mind immediately. First with the idea of turning the engine upside odwn would be the oil pan, oil pickup, and the oil system in general. Second, by turning the transaxle upside down you run into the issue of oiling the transaxle. The passages all work top to bottom. When turning 180 degrees is that the passages will not run in reverse. No oil means burnt bearings. Adapter plates and VW or Porsche transaxles would be the first choice for me if I was to start a project like this.

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FOr someone with the means to do so:

 

It is possible to put the crownwheel in upside down, but the teeth will no longer mesh correctly with the pinion since the pinion is offset. SO.... what is needed is a re-cut pinion. Thats all. So someone needs to hunt high and low and find a R160 or R180 diff head that has the correctly cut pinion, the front diff from a datsun pickup might be a candidate, as are many other nissan / subaru vehicles. Or alternatively cut a pinion with the correct teeth. This wont work with e dual-range trans, since the dual-range and crownwheel will both want to occupy the same space.

 

But simply flipping the trans upside down would be easier. The shifter points straight out the back of the trans, so its not an issue. The crownwheel would be high and lubrication and fluid level would have to be carefully considered. the Bellhousing would have to be redrilled/welded/dowelled but that is possible. Some one do it and prove its easy!

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Totally off the wall, but I thought of it once and it would fit here.

 

The knuckle/hub assy on a HMMWV (Hummer) is ~2:1 reduction, and the direction is reversed in the reduction. If you ever have followed a HMMWV, you would see that the axleshafts are spinning BACKWARDS relative to vehicle motion.

 

Therefore... stick the engine out back, adapt a set of HMMWV reduction hubs to your halfshafts (HMMWVs are four-wheel independant suspension), and go 1/2 as fast (with twice the torque). You would also gain some clearance at the halfshaft b/c the input is up top.

 

I know... crazy but possible.

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