12A Transmission cleanup and switch questions
 

So, here we have the transmission that came from ole Rusty. I had drained it and added new fluid when I got it running two years ago now (wow! time flies!), and then as you can see, it leaked everywhere. I need to clean it up, replace the front and rear seals while I have it out, and maybe the bearings too. Should I replace the bearings or just the seals? Not sure and didn't find anything specific when I searched the forum. Any help is greatly appreciated!

http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

As you can see in the picture below, the wires that go to the backup light switch have come off. Any idea how to tell which wire goes to which post at this point? Does it matter?

http://im1.shutterfly.com/media/47a4...D720/ry%3D480/

I'm pretty sure the reverse light is just a switch that when open = lights off and closed = lights on which would mean either way should be fine.

Excellent, thank you! I'm electrically illiterate. Failed that course miserably... :lol:

Looks like an SA 'box. The front cover bearing is no longer available, tho maybe the gasket for it is?
I think most everything else still is. Rear for sure. You might want to replace the shifter rubber covers too.There are three of them.
Some bits:
-speedo connection oil seal: 9958-60-8166
In fact, Mazda made a "shift kit" for the SA that was a set of nylon bits and pieces that go in where the shifter sits:
-"bush set": 0305-99-178
Might be a smart bit of service. Was not a very expensive kit.
Would start with Mazdatrix for prices and availability (be warned they have a funky way of re-ordering the above part numbers…!)

Stu Aull
80GS
Alaska

Assuming this box has a few miles under its gear train. As long as you have it all torn down, it's normally cheap insurance to replace the bearings, seals and any worn syncros / shift forks, especially if its got a lot of miles on it. The input shaft bearing tends to take a beating and I'd at least replace that. This is where a good manual comes in handy and there is a one just for SA transmissions. Complete disassembly requires some pullers and special tools and its important to get all the shims and spacers installed correctly. It won't be cheap or exactly easy.

Thanks guys for the advice, and thanks Stu for the part numbers! As you can see, it has developed leaks over time that quickly became evident when I drove it around a bit. I don't have the SA transmission manual, but my FSM tells me I have to pretty much disassemble most of it (except maybe complete disassembly of the gearing inside the intermediate housing) so I can clean up and reseal each side of the intermediate housing. I'm not very confident I could completely rebuild it without mucking something up, and I don't have the special pullers and tools. Would you guys roll the dice on just replacing seals if doing so wouldn't require special pullers and tools and complete disassembly to do so?

The special pullers and such come into play when taking everything off the shafts, not necessarily just getting the major sections apart. Auto part stores loan tools normally if needed. Sgt Fox probablly has the tranny manual on his site for download: Foxed.ca - Mazda RX-7 Manuals

You can always just replace what might be obvious and put it back together, just sayin the time to perform "preventitive maintenance" is when its already apart. Might save you from pulling it all back apart 6 months down the road. The odds depend on the condition its in.

Take note of how much debri and contamination is present inside the box, clean things up and check the bearings for smooth spining operation and excessive play between the inner and outer races. Some clearances can only be acurately checked with feeler gages and micrometers. Once apart, you can always take a questionable part or assembly to a local transmission place to get a 1st hand opinion. Chances are though, they will error on the safe side and tell you to replace it.

THIS-
Mazda Built 4 and 5 speed manual transmission parts, and overhaul kits - Drivetrain

-seems like a pretty reasonable priced place to get the internal stuff if you are inclined to get Adventurous…

Stu Aull
80GS
Alaska

Excellent advice Bonzai, thanks! This will be a good "learning" project, as has the entire rebuild on ole Rusty. I didn't see a manual for SA transmissions on the foxed link, but I do have all the other 1979 manuals on there, and the FSM and Service Highlights both have instructions for the transmission, so if one of those two are the manual you referred to then I must have what I need, manual-wise. I'll crack it open soon and poke around and see what condition it's in.

AHA! That's a link I had run across early on in my ownership of ole Rusty a couple years ago and forgotten about - thanks for turning me back onto it Stu. It's now saved as a favorite. The transmission seemed fine the few miles I drove it, so hopefully it just needs some new seals but I'll find out exactly soon enough.

Thanks Stu and Banzai for your help and guidance! :icon_tup:

Glad to help.
FWIW the Mazda OE Tranny repair booklet Banzai is referring to is _specific_ and unique to SA. It is a separate manual, not "within" a larger manual… unfortunately.

Stu Aull
80GS
Alaska

Yea, sorry I looked and that particular manual is not on Fox's site. I did compare it to the 79 FSM and the 79 service highlights manual. Either of those will get you through a rebuild. They contain a lot of the same info and even a little more when it comes to getting the box in and out of the vehicle.

The 79/80 transmission manual does have a nice fold out exploded diagram of the whole gear train, listing every key, clip, washer, shim and component. Makes it easy to see the order of assembly on each shaft. It also contains a few more in depth inspection measurements and lists out all the identified special tools. They also made a rear diff specific overhaul manual.