Rear differential drain plug part number

I believe all the drain plugs are magnetic from the factory. In your case you'd have 4 - one each in the front diff, rear diff, transmission and t-case. If they aren't that's the four that at minimum should be.

 

I’ve got a comment, observation and a question. I personally believe, in theory, the larger magnet could/would be better providing there is no obstruction- which I don’t believe there would be. This is evident when we pull our plugs and find small particles clinging to the plug.

Part number for the rounded plug above is 90341-18035. The hex is 90341-18044.

Now my question. Do we believe the filings remain there AT ALL TIMES or just when the oil sets when the vehicle is not in use? If they don’t it means they are running freely in our differentials wreaking havoc unbeknownst to us. Hmmmm

If you aren’t aware of the hurricane inside our differentials take a look at this video beginning at time stamp 3:10.
https://youtu.be/9-yG3D3JBRs

My heart and head says the magnets do nothing to contain the particulate during operation due to the ferocity of the gear oil flow shown in the video. BUT, why then would Toyota engineers spec-out the larger magnet shown above for the Land Cruiser? Toyota wouldn’t “ADD” cost without any actual payback- right? So, I’m going to purchase the larger magnet plugs for the front differential, the rear differential, and the transmission drains. I’m going with the 10mm hex on all three and even think that’s an upgrade to the 24mm hex on the rear differential. We’ve seen here and some YouTube videos how the hex nut can get compromised while the thinner relief of the rounded 10mm hex nut coupled with its internal socket could reduce those issues. Btw, the part for the larger magnet on the 10mm hex nut plug is 90341-18035 and costs $3.90 at https://www.toyotapartsdeal.com/oem/toyota~plug~for~rear~differential~carrier~cover~90341-18035.html

 

The wear happens regardless, so whether you have no magnet, a short or tall one the metal flakes are there. So the difference is the tall one may collect more of them in theory. When you pull out the plug you'll see they stick to that magnet like crazy, to the point that you have to really clean the sucker with brake cleaner and compressed air.

So I think the layer that settles on it remains there and the argument is you should drain gear oil regularly until the drain plug comes out without an excessive amount of flakes left. Eventually the gears break in, their wear surfaces harden and the continuing wear is minimal and barely a very fine powder. You should only see sizable debris initially with brand new gears unless you damage the teeth or something.

Further, you also see that a cone of debris forms on the magnet. It's not necessarily a tall one since the magnetic field of the magnet and collected debris weakens fairly fast. So maybe Toyota found that the tall one even if it clears the gears doesn't actually collect any more than a short one if it constantly gets swept clean or something. I dunno. In this case the situation seems like a little bit (small magnet) helps a lot and more magnet is only marginally better. Being a global truck the Cruiser also might see zero maintenance in some situations so service intervals might be measured in years in severe duty applications like mines and insurgencies.

 

Sub'd.

 

I’m actually going to be installing a different drain plug for the rear differential. The plug that has the 10mm hex nut is rounded and shallower profile will protect it from damage better. I’m also going to be high temperature neodymium magnet that only provides 1/8”. The pull force is about 3 lbs compared to the OEM magnetic plug that has a pull force of about 0.25 lbs.

If anyone is interested I can provide pictures of the plugs and magnets.

 

Yes, interested. Please provide pics of plugs/magnets.

 

For those of you who would like to change their rear diff drain plug to something with a lower profile that should reduce the risk of catching the plug on a rock here’s some information. In the event your plug gets hit a socket might be difficult to get on. A 10mm hex is a much safer bet.

The left plug is the 24mm socket plug that is OEM while the right plug is the rounded 10mm hex. Diameter and pitch is the same [M18x1.5].

Part number for the 10mm hex is 90341-18016. The magnet is 1/16” thick and has a pull force of 3.1 lb and is good up to 302F. MUCH stronger magnet than OEM.

 

This is fantastic, thanks!

Edit, just to be clear, the magnet already comes with the above plugs or did you have to purchase the magnets separately?

 

Just to add a little info - unsure if it changed at some point but my transfer case and my transmission did NOT have magnets on their drain plugs.

 

Mine neither but I’m adding some neodymium magnets to mine. Also changing out the weak internal transmission pan magnets to much stronger ones.

 

If only this came up sooner I would have done the same. For reference, where did you get the magnets?

 

https://www.kjmagnetics.com/products.asp?cat=167

 

Here’s the whole gang for you. Left to right are…..

1. Front diff plug with weak OEM magnet. I have a much stronger high-temperature neodymium arriving tomorrow that I will bond-on.
2. The new rear differential 10mm low profile rounded plug with a high temperature neodymium magnet on.
3. Transmission drain plug and neodymium.
4. Transfer case and neodymium. Using the standard 14mm socket because there’s no risk for damage like the rear diff drain.
5. Four (4) neodymium magnets that will replace the weak OEM transmission pan magnets.

All will be bonded using high temperature JB Weld minus the transmission pan magnets.

All magnets are high temperature versions that work in environments up to 302 Fahrenheit.

 

I would stay away from the 10mm hex diff plugs. They strip out very easily. Its very common to strip them on the front diff for the tacomas and 4runners.

 

This is the exact reason I got a diff skid. I didn't want to destroy that drain plug.

 

Here’s the 24mm front differential plug with the high temperature neodymium magnet. These magnets are so strong I think this front differential magnet will pull particulate from the rear differential if there happens to be any there, {wink}.

I simply took the stock plug with the weak magnet and bonded on this stronger one.

 

Did anyone ever try the long magnets in the front and rear diffs?

 

Not the OEM long magnets but I did install the neodymium mage nets to the stock bolts.

 

I bonded the magnets onto the plugs.

 

I'm too scared to do that, lol.