bgpzfm142;129485 wroteWill explain in more detail tomorrow with some more pictures.
(well, okay - I'm running a bit late...)
As
@Vee_Que pointed out, the bellhousing on the AW7x does indeed go back to the body of the transmission and includes the oil pump and overdrive.
This comment, supported by the esteemed Mister Bear, required further investigation. So I whipped the bellhousing off of the educational AW71 on Monday afternoon to investigate further, but then ran out of light to take pictures.
As you can sort-of see in this photo, there's a tube-like section of the bellhousing, of length 96mm, and a internal diameter of... uhh, bigger than my venereal calipers could measure precisely, but tape measure method says ID of 205mm. That figure will need to be measured more accurately if there is machining to be done... (see * below)
Which fits over this shiny shiny part of the transmission casing.
(It looks a bit... you know,
nude without the bellhousing section on it, doesn't it? I'll refrain from making other simile..)
However the issue that arises, due to this method of attaching the bellhousing, is what one does when one wants to replace said bellhousing as originally supplied, so that the transmission will fit something else. It's not nice and simple like a BW35. The oil pump is sealed by an O-ring back at the main section of the trans, and another O-ring at the oil pump itself. It's almost like the oil is designed to 'leak' a little into this section of the bellhousing as a cooling measure.
So it appears a big tube of some sort is needed to fit over the oil pump assembly, so that it can work as it was originally designed. However, we also need to secure the (replacement) bellhousing to this tube.
Just to see if the existing aperture in the 164's BW35 bellhousing was big enough to accommodate the oil pump, I just hung it on there / held it in place, for photographic porpoises.
Okay. So after all that, what's next?
This is where I must ask the advice of you, to find out the best and least expensive way to tackle this issues.
It seems to me that -
1. We need a 96mm long tube section to slide over the front end of the AW71, so that it can house the oil pump, etc.
2. We need to be able to attach that tube section to the transmission itself, as well as to the adapter plate.
3. Finally, we need an adapter plate to fit between the 164 bellhousing and the front end of the 96mm tube section.
To tackle #1 and #2, it might be possible to cut off the required 96mm back section of the old bellhousing, and then attach the adapter plate to that sawn-off section. The existing bellhousing to transmission bolts would connect the 96mm back section and the adapter plate to the transmission itself. The oil pump has plenty of clearance to fit through the 164 housing, and then the adapter plate could simply use the six bolts already on the 164 housing to bolt the two together.
Alternatively, perhaps, it may be possible to machine up a 96mm long and 205*mm ID tube section, with also has the mounting lugs on it at each end for bolting to the transmission, and then bolting to the adapter plate.
Another alternative is that there may already be a Toyota A43D transmission Out There that has that 96mm x 205*mm oil pump tube terminating in a flange closer to the oil pump face plate, but I don't see anywhere nearly as many cars as a professional mechanic to know whether or not such an animal even exists.