Outlander Rear Motor - Spinning/Flipping

[Pete9008]

I plan to use an Outlander rear motor in my conversion due to it's compact size and weight and reasonable power. The only issues is that I'd prefer to have the motor in front of the axle line rather than behind it for a number of reasons (weight distribution, clearance to suspension components, wiring convenience. The question is whether to reverse rotation and/or spin the transmission around a vertical or horizontal axis?

I hadn't been able to fin any good pictures and I'm not to keen on pulling my gearbox apart until I'm in a position to do something with it. Fortunately FFMan was kind enough to let me have the spare bits from his gearbox (not needed as he has mounted the motor directly to the BMW gearbox) so this has allowed me to have a good look at the lubrication systems and see what the implications of each of the options are.

This is what the inside of the box looks like. No gears included but the differential is at the bottom pretty much filling the space, the intermediate gear is in the middle with the motor shaft/gear at the top right hand side (the holes that the bearings fit into are clearly visible):

The nominal oil level is marked in blue. You can see that there is one detail cast into the case that does affect direction of operation, there is a wall, cast into both case sides, that extends the wall of the case around the ring gear. This, along with the rotation of the diff ring gear, acts to provide a continuous spray of oil (green arrow) onto the intermediate and motor shaft gears and bearings. Based on this I think running the gearbox in reverse would be a bad idea, the intermediate and motor shaft are well above the oil level so the amount of oil getting to their bearings would be significantly reduced.

Instead my current plan is to rotate the box around a horizontal axis to bring the motor in front of the axle line, something like this:

Again, proposed oil level shown (filled though old drain plug with old fill plug becoming the drain - not ideal positions but good enough). Because the motor is still spinning in the normal direction this maintains the old spray lubrication for the gears (green arrow). I'm a little concerned that some of the bearing oil drain channels also cast in are now facing the wrong direction but am reasonably comfortable that there will still be enough oil getting to all the bearings especially given that the intermediate gear is now partially in the oil.

The main problem with this is the gearbox breather. This is marked in red above and would normally be at the top of the box. The two channels form a labyrinth to control the oil and then there is a small hole (where the small red circle is) though into the void between the gearbox and the motor. There is then a drain hole from this void to outside. With the gearbox rotated this isn't going to keep the oil in any more so the plan would be to block the small hole (either weld it or tap a thread and plug it) and then create a new breather from the new top. Not too sure how this will affect the water coolant loop - it's possible that vacuum bleeding will now be needed to get all the air out. Gearbox mounts will also obviously need a dose of looking at too!

This approach gets the motor in front of the axle line and also brings it down both of which help with packaging and weight distribution. The HV cables will move from the back of the car (where they were a little exposed) to right next to the inverter.

So finally to the question, can anyone see any problems with the above, or an easier way to achieve the same end result?

[4markowen]

viewtopic.php?p=30293#p30293

Seems to have it upside down without problems. I'm sure there are other mentions of this motor in all sorts of orientations and running backwards and forwards.

That could be anecdotal though and obviously depending on application.

Curious as to what you go for as I've not got to the point of how I'm going to orientate the one I've got (also mainly if it'll fit in that orientation in my project)

Finger in air, so long as the friction/contact surfaces are still sufficiently lubricated whilst working then there shouldn't be a problem?

[Pete9008]

viewtopic.php?p=30293#p30293

Seems to have it upside down without problems. I'm sure there are other mentions of this motor in all sorts of orientations and running backwards and forwards.

Thanks for the link, had somehow managed to miss the earlier posts in that thread, there are some more excellent pictures of the gearbox innards here viewtopic.php?p=16683#p16683

Not sure whether aot93's conversion is on the road yet but it's encouraging that it spins happily upside down.

Curious as to what you go for as I've not got to the point of how I'm going to orientate the one I've got (also mainly if it'll fit in that orientation in my project)

Finger in air, so long as the friction/contact surfaces are still sufficiently lubricated whilst working then there shouldn't be a problem?

Having thought about it a bit more I'm much happier with the idea of spinning the box compared to reversing the rotation, the standard orientation running backwards does look like it could run the bearings a little dry. Fairly sure I'll spin it as shown above but possibly rotated a little further. That will bring the HV connections to the top ideally positioned for connection to the inverter. It also looks like it will position the coolant pipes in a much better position for a rwd car.

Edit - What car are you putting the motor in, any more details anywhere?

[4markowen]

Not taken the plunge and committed to a project page yet. Plan is to put this or a Toyota MGR into an Audi A2, which I think is getting a little cliched as a choice of project but does lend itself really well to a conversion, being Aluminium meets rule 1 of not being a rust bucket.

[Pete9008]

I do like the idea of no rust to deal with! Spent a couple of hours yesterday under the tow car topping up the wax under seal. Job I've been avoiding for over a year, horrible black sticky stuff and the rust still comes back!

Look forward to seeing a build thread