I'm just looking for the diameter of the threaded portion of both of these drain plugs. I know, random question, but I've asked a few people and they always assume I want to know the size of the wrench I need to loosen them up. Or I ask the parts department at the dealer, and they have no idea (...useless). I need the actual size specification of the bolts (M16, M18, M20?). I mean, pitch would be nice too, but I'll take what I can get.

I was thinking if you were selling an extra trans or diff, or were changing out your fluid anyway, you could do a quick measurement for me. I'd appreciate it!

 

Well that is a unique request. I will check one that I have laying around when I get back to work tommorrow. The drain plug and the fill plug are both the same size and have a 10mm allen head...I'll let ya know on the threads though

 

Isn't it? haha

That's good to know that they're the same size, though. I thought so.

Not to abuse your generosity, but is the plug size, pitch, and length of the threaded portion too much to ask for? You can just give me the length of the plug in general, if that's easier.

Thank you.

 

The threaded portion of both plugs is the same: M18 x 1.5 thread pitch / threaded portion is 10mm long.

The drain plug has a magnet past the threaded portion overall length is right at 30mm.

Hope this helps you out

 

Check out what I've put in bold above.

But thank you very much Z_ology!

 

Yes, there are only six threads on the plugs.

The info for the plugs that I gave you is for the diff not the trans. The trans plugs are similar in size, but I don't have any laying around to measure.

 

Oh ok. That's no problem. Thanks for clarifying.

 

Here's some pics I took of the plugs if it helps...

https://my350z.com/forum/3979891-post197.html

https://my350z.com/forum/3979910-post198.html

 

The fill and drain plugs on the differential and the transmission are all the same, magnet excluded. It's easy to add a magnet to any or all of them; just find a 1/2" diameter magnet and epoxy it in.

Asterix

 

Totally helpful. Thank you.

 

I'm worried it won't hold

Or the epoxy will react with the trans fluid, the magnet will fall off, and then BANG, CLANK, GRRRIND....ouch.

Hey vo7848, if I were to still go this route, do you happen to remember what that inner trough at the end of the trans plug looks like? Is it flat at the bottom of the hole? I don't remember from when I drained mine last. Just want to make sure there is a flat plane to apply the epoxy and magnet.

 

Sorry bro, I don't remember. BTW, I personally wouldn't take the risk. I'd just go buy a new one. That's of course, if ya asked me...

 

I know I know...

The only reason I'm thinking it makes sense for me to use an OEM plug and epoxy a magnet is because I called a distributor of magnetic plugs who told me that after market magnetic plugs are simply regular plugs drilled out and a magnet is epoxied in. How about that?

I am calling the company of the epoxy I plan to use to discuss temperatures, tenacity, and resistance to transmission fluid.

If my handiwork fails after taking the necessary steps, then F my life. I am bad-luck prone anyway, but I can't live in fear.

 

If you are looking for a magnetic plug...why not just get a stock one? It has a rather large magnet and I have not ever seen one fall off the plug. This seems like alot of effort to design something that already exists and works

 

Won't the magnet interfere with the gearing in the transmission because of how much it sticks out of the plug? That's my only concern.

If anyone has a trans laying around, they could shine a flashlight in there and see just what's behind that hole. If there's nothing, then (like you said) there's no reason to go through this trouble, and I'll just use the same plug found in the differential.

 

good point, however, if their epoxy job fails and the warranty is in effect, all will be fixed....If YOUR epoxy job fails and the car is under warranty, you're sol.

gl

 

Regardless, it'll be a headache. Forget the DIY.

I'm changing the title of this thread to target people who can probably provide info about how much clearance is behind the drain plug hole. I PMed Sharif@Forged about this a while ago, and he said I should be fine. I still need a few more opinions before I use a longer plug in the hole, or else I'll be starting a very different type of thread. I guess I could stick a small pipe or something in there and run through the gears to see if it comes into contact with anything, but I'd rather not.

 

I know this isn't our type of transmission, but it's a good illustration of my concern.

See how the drain plug is already pretty close to the gearing? It seems to me that another couple of centimeters, and there will be contact.

 

Ok I get where you are going with this...your questions make more sense now.

I don't see where there would be any clearance issues with using the magnetic plug from the diff in the trans.

 

Something else that sort of complicates things is the way I will be swapping the plugs out. I planned to unscrew the one that's in there and then quickly rescrew the new one in, hopefully only loosing a couple of ounces of fluid in the process. I won't be able to do any clearance checking of what's inside the bell housing if I'm going to concern myself with preventing fluid from draining out when the hole is open. Normally I'd just do a re-fill, but I just swapped the trans with Amsoil fluid, so I think it would be a little wasteful to drain all that good fluid out and spend another $50 to refill with new.

(Between my lack of knowledge about all of these things and my arguable cheapness, this thread makes me sound like such a Noob)

So I can either 1) buy some more fluid and do a flush again 2) do the quick swap of the drain plugs without draining fluid 3) drain the fluid and reuse it again (ghetto, but it's an option), or 4) just wait another year until I hit the next trans fluid change interval and deal with this project then.