Differerential Drain Plug Rock Damage

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Oct 30, 2008
Severn, MD
So long story short, both the front and rear differential drain plugs have suffered at the hands of some previous owners rock adventures. Anyone have any experience with this? On each one, at least 1 of the six sides of the drain plug are ground onto the protective ring and prevent getting a socket on there or even turning the plug. First thing that comes to mind is to cut off the protective ring around the plug with a cutoff wheel, then weld a new protective ring back on. I have searched multiple forums and not found anything applicable, rather just stuff on folks rounding off the drain plug heads with impact wrenches or 12 pt sockets. I will see if I can post a couple pics tomorrow...

Can you weld a nut on top of the drain plug? Kind of like this:

Use a tool to clean up the sides. Cut off wheel if you have to. You can always weld back in the gaps. Probably easier/better than cutting the ring off entirely.
And you can drive the plug out with a cold chisel. I would just cut out the ring, and weld a new one back, and that's if you don't want to weld up the plug all together. For trail use--nothing but problems. I even carry the tap for the plug threads, I've seen so many messed up.

You can also weld a nut on the plug and turn it out. This is a last resort but works great, and you'll need a new one afterwards.
FWIW I have seen TWO different plug head thicknesses, the thinner versions are very soft and round off at the first chance they get, so if you can cut off the ring, chisel out the plug and then put a new plug in to prevent splatter entering the differential, weld on a new ring but thicker and stronger, then use the thicker head plug.

Do it one and do it right.


Once you have it out, replace it with one of the new ones that have a 10mm hex socket on them.


Much better design (with a magnet to help collect particulate)
X2. Weld nut on. Replace with hex/Allen style.
Thanks for all the good info. I am curious on the suggestion to simply close off the drain plug. How are you changing your differential fluid if you do that? I am more used to Dana44/60 and the easily removable covers... I do like the idea of going to hex head bolts and will do that for sure, seems like it will save time in the end and prevent many of these issues. I also don't plan on dragging this through The Hammers like some previous owner did so once it is fixed, I doubt I will have similar issues again. Lol
Even welding a nut on, the damaged ring is not going to let it turn for sure. I will definitely need to open up the inner area before welding the nut on. Is there an official spec for that protective ring or just use some appropriate diameter ChroMo schedule 80 (or similar) tubing?

I think the plan right now is:

1) Use a Dremel or similar to clean up the inside enough to allow the nut to turn
2) Weld on nut to remove drain plug if it is necessary
3) Replace with that spiffy magnetic hex head plug
4) Repair protective ring with some weld or entirely with tubing if needed

The bigger question to me is knowing what a pain this is, when the hell was the diff fluid last changed? Hahaha Ready to put some Amsoil Severe Gear 75w90 in the front and 75w110 in the rear, I imagine the diffs will be quite happy about that change.
Dremel with the mini carbide wrasp bit will work for sure.
The trouble with the hex is once it is hit then you cannot get the key in, and of course as it is round on the outer edge it is harder to chisel off than a normal headed plug...just saying.


Next question, and forgive my unfamiliarity, but who is a go-to guy for east coast Toyota factory parts? I know we have a handful of Toyota employees in here but the only name I know offhand is Beno, not sure the process to go about ordering these plugs. On top of that, I need a full OEM tune-up kit (plugs, wires, dist cap and rotor, air filter, fuel filter, large oil filters, all 3 belts, and a crank seal + oil pump seal + new bolts because it is unhappy).
Toyota doesn't sell the hex plugs. I think mine are from trail gear.
Toyota doesn't sell the hex plugs. I think mine are from trail gear.

90341-18021? That is a Toyota part, just not sure what model comes from... But I will check Trail Gear to see what they offer.
Yes, that's a Toyota part. I believe it's from a Sequoia IIRC.


Don't forget the crush washer.

Look for CDan, Beno, Sam Stewart ... each works at a Toyota dealership that gives Mud discounts.
Good to know...the trail gears feel a little cheesy. I'll switch to the sequoia when they get damaged.
My rear axle fill plug was impossible to remove. Did everything possible to remove on my own including cold chisel, plumber wrench, etc. eventually got a nut welded on and of just twisted off by hand. Likely heat helped. I have gone to the hex drain plugs now.

I'm in Georgia and I just call Beno when I need things. I am sure Sam Stewart and CDan are probably the same. Beno is great and he knows stuff. I often have no clue all the parts I need, just what I want to work on...I'll call Beno and just tell him what I'm doing and he makes sure I get all the parts I need so I don't miss anything. He's been really helpful.
The trouble with the hex is once it is hit then you cannot get the key in, and of course as it is round on the outer edge it is harder to chisel off than a normal headed plug...just saying.



X2, and if it's being wheeled in the rocks, the hex hole gets impacted with rock making the hex useless. Have had to weld nuts on several to get them out, we always go back to the original type.
On the protection ring, do what is needed. On rigs that don't see much rock work, we have just built them back up with weld metal, works.

On rigs that see more rock.


We have added rings and welded, built the inner/old ring up to match.

In some cases, have added 1/2" plate.

Have also cut a circle out and sunk the plug into the housing, but that's a ton of work for little gain. Have welded the plug in and removed the lower stud to drain, for most, not my preferred method, it's slow to drain and like to see what is on the magnet, gives an idea of diff condition.

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