Here's what went before:
Johny wrote: Hi weber. Do you know how Ross overcame the problem of lubricating the rear oil seal (around the tail-shaft slip-yoke) without swamping the front motor bearing with oil? This is my current concern with using my tail-shaft housing. Sorry - a bit off topic here.
weber wrote: Not too off topic since one aim of many AC conversions is to eliminate the gearbox. But you can email me direct on d dot keenan at bigpond dot net dot au.
I have emailed him the question and will let you know. But I suspect he didn't solve it. I note, for others who may not be familiar, that the tail end of the gearbox of a front-engine rear-wheel-drive usually has a plain bearing that supports the front end of the propshaft (also called confusingly tailshaft or driveshaft in various countries) which is driven internally by a spline that allows for some misalignment. This plain bearing, and the spline, need lubrication, but you don't want your electric motor filling up with gear oil. 90 grade oil between rotor and stator could be a serious drag.
My own thoughts are to put gear oil into the tail casing, while on level ground, with the propshaft out, until oil just starts to run out the back, and rely on it moving about, as the car accelerates and goes up hills, to get it to the spline and plain bearing. And rely on the motors own oil seal to keep it out on the downhills and decelleration. Sounds a bit risky I admit.
If it did get into the motor, could it be flushed out with a solvent without disassembly?
Johny wrote: I'm impressed that you knew what I was on about. I agree it's too risky. One solution is to place a blanking plate halfway along the tail shaft housing and put yet another oil seal there. The problem may be trying to assemble it all.
My alternative is to NOT use the tail shaft housing and instead use an external slip-yoke as per a4x4kiwi's Electrolux (even my wife laughed at Mal's nickname for the Hilux).
Since AC motors are less expensive with only foot mount (as against foot and face mount) this is also cheaper (at least for the motor). It does require I get the motor as rear-ward as possible to not have an excessive length drive shaft - which is why I seek a 132 frame motor so that it fits in the transmission tunnel.
Anyway - the tail-shaft housing still has appeal if problems can be solved. I just happen to have a spare gearbox...
I agree that the problem with the blanking plate and additional oil seal is that the spline on the end of the output shaft is usually bigger than the shaft and so won't pull through the new oil seal. There may also be a speedo takeoff gear to consider.
Here's another idea, in the spirit of brainstorming: Drill a hole through the motor's oil seal (or face plate just below oil seal) and fit a tube so that any gear oil, that makes it past the motor's oil seal, drains outside.
Or an intermediate solution between the above two: Screw and seal a small housing to the motor face-plate, with an additional oil seal in it and a drain tube to outside. The housing could be a small aluminum cup or bowl or lamp reflector, or maybe even the lid off a pickle jar. No disassembly problem then, because it's part of the motor. Just have to make a seal where the drain tube comes out through the gearbox tail casing. Hmm. Maybe you need a tube in the top to let air in too, if it's a skinny drain tube with very viscous oil.
Sounds bad to just let it drip on the road, but there should be hardly any, and ICE's drip all the time. However you could have a trasparent plastic reserviour that you checked and emptied periodically. It would be interesting to see how much there was.
Something else that interests me is how to do the coupling from motor-shaft to sawn-off gearbox-output-shaft or other means of providing the spline coupling to the propshaft.
By the way, I've taken to using the British term "propshaft" for the long heavy thing with the two cardan universal joints, even though my dad taught me it was called the tailshaft when I was a little squib crawling under cars with him. That's because some folks in places other than Oz call the gearbox output shaft the tailshaft and some folks call a shaft between the diff and a wheel a driveshaft.
Coulomb and I are planning to do an AC MX-5 with no gearbox.
Ian Hooper essentially built an open frame replacement for his MX-5 gearbox tail, with a sealed bearing in it. It looks like a lot of work, and paying of professionals.
And you mentioned a4x4kiwi's Electrolux (great name ). I found the relevant photos at
http://a4x4kiwi.blogspot.com/2008/08/mo ... alled.html
http://a4x4kiwi.blogspot.com/2008/09/en ... alled.html
In this case, it looks like a lot of work modifying the propshaft.
We plan to use a 132 frame motor as well (most likely one of the new ABB ones, 15 or 18.5 kW). We'd love to put the motor right at the diff, like this one in Kim Ryan's Proton.
More on Kim Ryan's Proton in this thread:
The MX-5 has an unusual drivetrain mounting, in that it has a rigid beam (called the PPF or Power Plant Frame) connecting gearbox to diff. This beam runs along one side of the propshaft, while the exhaust pipe is on the other side. The whole setup is hung on only 4 rubber mounts, 2 at the engine and 2 at the diff which has "wings".
By putting the motor at the diff (a rear diff, unlike the Proton) we'd save the weight of the propshaft and PPF. But we'd need to find two solid points in the transmission tunnel to hang the 92 kg motor off, and the motor casing would need to be rigidly coupled to the diff casing by something other than the PPF (e.g. a short tube as in the Proton).
And some people think that the PPF is there not only to resist the gearbox/diff torque reaction, but to stiffen the body in reagard to the suspension's responds to uneven surfaces. So it sounds like it would be difficult to convince an engineer to approve a motor-at-the-diff construction.
The PPF normally attaches to the gearbox tail casing, so if we keep that, and of course the propshaft, it looks a bit easier. We'd still have to have something rigid going forward from the induction motor to the original ICE engine mounts.
Any ideas would be greatly appreciated.
[Edit: Fixed yet another link broken by a dumb domain-name/directory-structure change by the forum administrators.]