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Pulled my 80 12a apart today and have a couple of questions:
1) rear gear pic (apologies for poor focus ;p) - the Atkins DVD sez to replace the oil seal on this. The ONLY seal I see is the one I am pointing at with the screwdriver tip. IS that a seal? Afraid to poke at it incase it should be left alone. No other seal came out with the gear, tho the 2 bushings still remain in the hole in the rear plate. Is the seal in with the bushings? Atkins DVD seemed pretty specific to the actual GEAR needing a seal...

2) rear housing (pic) - missing chrome along a couple of edges. Still useable?? AM I facing some sort of imminent failure (ie sooner rather than later) using this housing? Engine ran great with this as it was (so Why am I rebuilding? don't ask
Front housing is fine-

Thanks All - more dumb questions likely!
Stu Aull
80GS
Alaska

 

That would be the seal they are talking about. That housing has a little to much flaking for me. I don't like to use them if they have much more than 1/8 " wide strip missing. It would work, but I would try to find another one.

Ron

 

I rebuilt a 1982 12A about 2 years ago in my backyard.

There are 2 seals on the rear stationary gear. There is a o-ring type seal in that grove area. There is also the 'rear main seal'. This seal is on the back side of the stationary gear. New ones are bright orange as far as I know (I've seen 2 that colour). A new rear main seal is a very good idea because apparently if they get little nick cuts in them you can end up with a flywheel/clutch assembly covered in engine oil.

If the front is 'perfect' then find a 'perfect' used rear. Or just get 2 new housings and take damn good care of the engine.

 

mazda calls that the rear stationary gear o ring, it should be changed, they do leak. there is also the rear main seal, if yours is old it'll be blue or black, new ones are orange

2. that housing will run the same as it did before, HOWEVER it does look kind of tired. i see some chatter marks in addition to the peeling, all normal wear.

i'd price out some new housings, maybe have an eye out for some really nice used ones (these dont exist) and then put it back together.

 

Find another housing, Not only is the flaking more than I'd reuse, looking at the rest of the surface, that housing is on the short side of it's downhill leg.

 

Thanks folks - ya, bit worried about the housing too - engine's a rebuild so its likely a parts-bin special. Don't know how interchangeable the 80 housing is with newer ones??
Trying to do this on a budget (aren't we all? ) since I want to sell this 2nd car - but I also don't want to stick the new owner with a bad motor either.
Have a complete seal kit, so new main seals for sure - and now I'll eyeball the kit closer and see if the 2nd smaller rear seal is included.

Another Q:
are the ROTOR oils seals reusable?? As I said, this is a fairly recent rebuild (12-15K miles) - and the engine was damaged in STORAGE, not while running...
Thanks
Stu Aull
80GS
Alaska

 

the difference between the 79-80 housings and the 81+ housings is different air pump routing for the reactor vs cats. i am not sure how different it is, i suspect it could be made to work either way

the rotor oil seals, last a long time, inspect em, they probably were reused on the last rebuild too.

rotor oil seal ORINGS should be ok too @15k, look at em really close, and be picky