You are going to loose a sizable amount of fluid trying to do what you are talking about. So I would either catch the fluid in a clean container and then refill the trans. Or just let well enough alone since the trans is working without the magnet. Nissan seems to like to over engineer stuff so if the trans needed a magnet it probably would have had one

 

I'm going to do the drain and refill. That way I can stick my finger up in the hole (hehe) and have someone shift through the gears, and if my finger comes off, then I'll know there is not enough clearance. LoL I wonder if it's okay to shift the gears gently w/out fluid in the trans?

The only reason I'm even bothering asking about this stupid drain plug is because I plan on keeping this car indefinitely. It's my first brand new car, and I will take on another car payment before I ever trade it in for something "better". I just want to make sure I'm taking all of the preventative measures I can to get the maximum life out of the original parts. Don't get me wrong, I do still drive the thing

Nissan actually does have a fixed magnet in the trans, but the only way to access it is to disassemble. Not quite sure what the logic was behind that decision. I gotta say, though...the Z every time I'm under my Z I always think to myself that it's pretty solidly engineered car from the factory, overall, especially the drivetrain. I'm no professional, but in comparison to other car's i've looked at, the driveline looks "beefy".

 

Oh, come on. Pick the right epoxy that's impervious to oil once cured. Easy. The epoxy is cheap insurance anyway. There's no way you'll get the magnet back off the steel plug even if you try. The end of the plug is a cup. If your transmission gets hot enough to demagnetize the magnet, you have other problems.

My '04 came with a magnet in the plug only for the differential drain. So, I surfed over to Courtesy Nissan's site and ordered that plug so I could use it (with magnet) in my transmission. The one that arrived had no magnet! It has a nice cup on the end ready for one, though.

vo7848's photo:

If you don't think your transmission needs a magnet or think Nissan has your best interest in mind and are worried about the magnet falling off, don't use it. Me, I'm going to use one. It sticks out all of 1/8". Yes, I'll check for clearance. That's easy.

Asterix

 

Yeah, if you look at courtesy's site, the part numbers and illustrations are switched it seems. The plug on the diff that looks like the magnetic on has the part number and description of the fill plug. That's probably where you went wrong. Not your fault their diagram is wrong, though.

 

I just got done measuring clearance, and the estimate I feel comfortable reporting back for anyone who may need to know in the future is about 26mm of useable space between the outer edge of the gearbox housing drain hole and the metal internal "secondary" housing. Since the OE magnetic plug from the rear diff is 30mm in length, clearly it will not work in the transmission drain plug location without coming into contact with this secondary housing.

If anyone is looking to use a magnetic plug in the transmission gearbox, I would recommend finding one that has around 20mm or less thread length (or total thread + bar magnet length if that's the type of plug you are using), to ensure you have enough clearance.

From what I have read (and I've read a lot) about aftermarket drain plugs, Lisle Corporation plugs seem to be of high quality.

Their specs for the M18x1.5 size plug show that it will fit without clearance issues.

I just ordered one from a company in the Mid-West. (I had quite the time trying to source the plug as Lisle is an OEM supplier and does not usually sell privately...neither does the company I ended up buying the plug from). I'll report back about fitment / quality when it arrives.

 

Thanks. That explains why the one I got had no magnet. However, it was good a good thing, since the one with the magnet wouldn't have fit according to your measurements.

I bought these hemispherical magnets from Lee Valley. They fit the cup on the end like they were meant for it. I scuffed the flat part with 80-grit sandpaper, added a little JB Weld for insurance, and I'm set.

With the hemispherical magnet installed, the distance from the crush washer to the tip of the ball is 19mm.

I almost forgot: I took photos.

Asterix

 

^^ did you paint that plug black?

Also, do you remember if the magnet was naturally attracted to the plug, or is the JB weld the only thing securing it? I think the plug is made of steel, but I just want to make sure.

 

Nope, the plug came that color. It's not paint, but some chemical finish. It looks blacker in the photo than in person.

The plug is steel. The epoxy is only for cheap insurance.

Asterix

 

Thanks.