Trans adapter time. As mentioned earlier the 722.6 doesn't bolt up to a M180/M127/M129/M130 engine even through the bolt patterns look very similar (with the inline engine version of a 722.6 bellhousing at least).
So I had a conundrum on how to go about this, taking into consideration things like starter location, ring gear location, keeping things concentric, making sure the torque convertor is seated once its all together etc. There's several things that ended up providing the answer for me. Firstly the starter; On the M130 the starter is on the right hand side of the engine, the factory sandwich plate that sits between the engine and gearbox has a provision for the starter. however on the 722.6 trans the starter clearance bulge is on the the left hand side. So which side of the motor do you want your starter? if you scroll up a post of two you'll see the oil filter housing sits on the left hand side of the motor, right where the starter would be, so you can't make use of the 722.6s starter mount. In which case you're now using the engines OG starter, which means you'll want to keep the ring gear in the original location...
So I yoinked the manual trans off that engine and too some measurements and drew some circles in Fusion360
Then realized I'd mucked up the overall diameter of the thing, luckily this was prior to sending away files to the laser cutters. Sent some files off and they sent back some lumps of metal
Have a 12mm spacer for the end of the crank, and a 3mm thick flexplate, plan is to scavenge one of the ring gears off the manual flywheels I have and weld that to the flexplate. I spent a rainy Sunday attempting to measure the bolt pattern for both the engine and the trans and had a test piece cut out of 3mm plate at the same time (the disc on the left) if my measurements were right I was going to get a thicker one cut and run that but you can see from the ticks and crosses on it only about a 1/3 of the holes lined up. Ended up getting a 12mm thick piece laser cut (the disc on the right) that utilized one of the factory dowel pins on the trans, that was to be my starting point.
clamped precariously in place, the OD was large enough to blank off the now unneeded starter bulge on the left hand side
Went around and marked out the holes I'd be using that didn't clash with any of the holes I would need on the sandwich plate, tapped one of them using the shitty tap set I had before buying a Volkel tap set based on someone on heres recommendation, holy moley did that improve my outlook on life. Whoever made that recommendation deserves an ice cream. Ended up here:
Jealous of my phone?
Whilst doing that the torque convertor was sitting on the bench next to the trans, at some point I moved the trans and knocked the converter onto the floor which caused a drama for later on but we won't talk about that.
Did some maths at this point. Decided if I wanted to run a 12mm thick adapter plate I'd need to reduce the thickness of the sandwich plate by ~11mm, a buddy came through and was able to do that for me, I have a spare plate if this doesn't work out, comparing the two post surgery:
That's the relatively easy side done, next step was to join that to the engine whilst keeping the trans concentric to the crank (well as much as I could anyway). There's a small win here in that the OD of the pilot on the torque convertor is the same as the ID on the end of that crank where the pilot bearing would normally go for the original manual trans (35mm). I carried this measurement over to the ID of the crank spacer so the Torque convertor could locate on it, the spacer picks up the OG dowel pin on the end of the crank so based on that assumption of it being a straight line I bolted the spacer up to the crank and slid the trans up to it, docking the torque convertor pilot in the hole. Took a brave pill and wiggled it so the trans looked straight up and down against the engine, rather than tipped to one side, and marked out the two holes for the starter then drilled and tapped those. Bolted everything back together, so far everything is lining up.
took the trans off, leaving the adapter bolted to the sandwich plate on the engine, removed these two as one:
Was then able to flip it over, mark out some holes and drill and tap those.
Then the moment of truth, putting it all together...
Booyah! that shit is attached. Had to do a bit of fettling but was bugger all. I need to change the blade on my vertical bandsaw so I can trim the excess off the OD of the adapter. Current issue is that its too tight between the flexplate and the converter, they rotate as one without being bolted together. We didn't get exactly 11mm off the plate when we machined it down, it ended up being about 11.2mm which I think is part of where the problem is, it's bringing the trans and engine too close together, in hindsight I probably should have aimed for 10mm. I think to get around this I might skim a bit off the end of the converter so it can sit further inside the bellhousing when seated, but I'm not sure how much clearance the input shaft of the trans should have inside the converter before it bottoms out, surely 1mm less isn't the end of the world?
Anyone got any insight?