My hazy decades-old recollection from my '72 beetle was that the engine case itself was threaded in the top left (ie. non-starter) side, into which screwed a regular hex-headed bolt driven from the transaxle end, thereby clamping engine and transaxle together as Steve asserts.sgkent wrote: ↑Wed Aug 16, 2017 2:40 pmwouldn't the captive nut be inside the engine bay so that that bolt pulled the case and trans together from the trans side, and engine bay side? Below is a 1971 dog house case. The top bolt on the starter side is the D bolt, and the one on the other side is a regular bolt as I recall although I did see an occasional one that had a pressed in captive nut on the engine bay side.SlowLane wrote: ↑Wed Aug 16, 2017 1:15 pmI think that you have encountered an unfortunate confluence of 1970 transaxle (which has the bolt-retention notch to facilitate spinning on the nut from the non-doghouse 1970 engine side) and the built-in nut of the 1973 doghouse engine (which would have been mated to a Beetle transaxle that didn't have the bolt-retaining notch). Lucky you.whc03grady wrote: ↑Wed Aug 16, 2017 11:55 amBut the bolt is semi-locked as well, by virtue of a notch in the bell housing. I could've gotten to a regular nut easily.
The round nut isn't stripped.
For this combination, going forward, it would probably be best to file away the bolt-retaining notch in the transaxle (so the bolt head can be turned freely) and embed a captured nut in the engine flange (to avoid having to try and get a wrench or fingers down behind the dog-house.
The top right fastening had the D-headed bolt with a matching flat in the bell housing to keep it from turning whilst tightening the nut from the engine side. I recall having to make certain that the bolt D-head was seated with the flat lined up correctly.
In retrospect, I suspect that the thread in the upper left hole of the engine case flange was actually an insert, since having threads in the soft magnesium case probably wouldn't have been such a good idea for such a critical mating.