I did an oil change on my trans and diff this morning.
The diff had a magnetic drain plug but the trans didn't. The old oil in the trans was a yuky gray color so I wanted a magnetic plug for it too. I went to Radio Shack and picked up a package of these 1/2" magnets for $1.79 that fit almost perfectly in the drain plug. I'm sure the magnet would hold itself in the drain plug but I used a little epoxy in the plug to make sure.
It's hard to see in the picture, but the plug on the left has the magnet glued in and the one on the right is still empty.
I used Redline MT90 and MTL mixed 1/2 and 1/2 in the trans and the shifts are much smoother. I had "notchy" shifts before, never had a grind though ( unless It was my fault. ).
Took a 200 mile drive through the mountains this afternoon and didn't have any notchy shifts. So far the Redline oil is much smoother.

 

All of the transmissions I've had apart have a magetic "donut" around the drain plug on the inside of the case. I am guessing that the diff case has no such room and they use a magnetic plug instead. This is the first RWD car I have owned since I finally know some stuff about cars and working on them. Of course you will never see the magnet in the tranny and I hope you never have to!! You may want to take that thing back out, man. I hate to think what may happen if it comes loose. Epoxy is difficult to mix perfect and what about the chemical reaction between the fluid and the expoy? There are too many unknowns and what ifs to sit well with me. I worry alot so I would have never done it but if you feel comfortable go ahead. Just trying to be helpful, not over-reactive. Anyone know if this is a bad idea?

Redline is awesome when it gets cold out. Much smoother than regular lube.

 

Thanks for your concern. I've had the pan off all the auto transmissions I've owned and they all did have a donut in the pan. I hope this 6mt has a donut in it but I don't know. I just wanted to be sure that there is a magnet in there somewhere so I put this one in the drain plug. The magnet is in there so well that I'll have to drill it out, or just buy a new drain plug, so I'm confident it won't come out on it's own.
I've seen epoxy used in engines to hold catch screens in the oil drain pathways to catch debris, so I don't think the epoxy will have a negative reaction with the trans oil.
I will check it in a few thousand miles to make sure the epoxy still looks good.
Thanks again...