Transmission Drain Plug “Rotten”

I just took my 2021 5.7L 4WD to a dealership for 80k service. Did all the fluids, but when I picked it up. They told me that the transmission drain plug was “rotten” and the plugs are on national backorder.

I live in the Northeast where I know they put some nasty stuff on the roads, but is that really a thing that the drain plug would rust out that much in 3 years?

I looked up the parts and it appears there are two drain plugs for the Tundra 35106a is the plug and 36106B is the washer/gasket. I’ve pulled up other parts diagrams that show the same “35106” but with different variations on the last letter for one or the other of the two plugs. Like F or Q.


Ive seen aftermarket plugs with magnets on them. Any good?

Service advisor couldn’t even give me an estimate for when the oem plugs would be back in stock. I rack up most of my miles in winter so dont want to let this go to much longer. Should I go with an aftermarket plug?

Thanks!

 

I'd just replace with a Fumoto and be done with the rust.

 

This is the way.

 

Have you looked at the plug? Did they overnighter it or turn it the wrong way and strip it out some with their impact wrench?

I doubt it "rotten".

 

You’d need two valves for the trans pan. Have you done this with luck? Seems like the fill check is recessed a bit, if I remember correctly. Did you need an extension for the Fumoto in that port?

 

You definitely couldn't use a fumoto in the check port for the simple reason that you'd never get a correct reading

 

I havnt gone under the truck to see if they stripped the head with an impact wrench. I need to do that now that you mention it - makes sense that he may have done that. I also doubt if the plug was “rotten” or even badly rusted. There are plenty of bolts under the truck that never seem to rust. Can’t imagine those being rusted beyond reuse. Do they always replace that plug as part of replacing the tranny fluids? If so they would have known they didnt have a replacement before taking the truck in for service. Seems like the kind of part that they would always have in stock at a dealership.

I see from the parts diagram that there are two drain plugs and one fill port up the side.

I’ll jump under the truck tomorrow am and report back.

Are Fumoto plugs superior in some way? Any chance you guys have part numbers for them? Thank you again!

 

Don’t waist your time putting a fumoto on your transmission pan.

 

I've never heard of anyone putting a fumoto valve in the transmission and I definitely wouldn't bother trying.

 

You don't replace the plug. You do put new washer or seals on them. The drain plug gets a crush washer type. The check plug gets crush washer type. The fill gets an oring type. But you only replace the plugs when dealers/ bad mechanics mess them up.

I also don't agree with a valve being installed. If you do all the work yourself maybe. But what's so hard about pulling a plug waiting for it to drain, then adding a washer and tightening it? I'd hate to be at a oil change shop/ dealership and the kid that just turned 18 opens it up to see what it does, and doesn't close it all the way and you drip out trans fluid untill your low on fluid and have transmission damage. Then they denied your claim blaming it on a aftermarket valve.

 

I'm calling bull shit.

There is no way your plug was rotted out.

I live in the rust belt. I drain and fill my '08 transmission fluid every other year. The pan is not rusted at all.

Those jag offs stuck the windy wrench on the plug and stripped it.

They owe you a new pan.

The quick drain valve would not be much of an advantage. The pain in the ass of pumping new fluid in the pan is much worse than unscrewing the plug. Spend that $20 on something more useful.

 

I’d agree. First time up drained mine, I about stripped one of the Allen holes on a plug because I didn’t pay attention and didn’t have the wrench fully inserted. I bet I would have screwed it up royally if I was using an impact on it…

 

Wast.

 

Thanks everyone. After watching a couple videos on the Fumoto plugs, I don’t think I want to use one. Main reason being that I’d be worried that the mechanic would screw it up and blame aftermarket parts. Not worth the risk. A normal plug shouldn’t be an issue.

Having said that, here’s a picture of the plugs on the tranny pan. Definitely pretty severe looking rust and don’t blame the mechanic at the dealership for not wanting to attempt it without spares on hand.

Wonder why these two plugs are so rusted when none of the other bolts are rusted at all? Can I get a stainless steel or galvanized plug and use stock crush washers with it? Anyone know the thread pattern on these plugs?

 

just get them here (https://www.megazip.net) You'll pay for shipping for sure, but they are OEM

 

My 2019 started rusting after the very first New England salt season. I sprayed it with Noxudol 700 cavity wax, it keeps rust at bay.

 

There is nothing wrong with those plugs.

The threads live in an oil bath.

They will remove with ease.

A quick wire brushing will clean the outside easily.

 

Yes and then give them a shot of fluid film or the like

 

One could clean them up a bit and weld on some quality hex nuts too.

 

Get the undercarriage sprayed before winter,I do mine every other year and we love salt in NH.

 

No.

Those plugs just need a bit of clean up.

The drain/level plug has an Allen head bolt that accesses the stand pipe in the pan. You do not want weld a nut to that.

 

There is actually no stand pipe in the pan.

 

1 is a plug that drains all fluid, the other plug is for checking the level.

Stand pipe is the best description I could come up with for the level checking plug. I'm sure Toyota has a proper name for it.

 

Some Toyota pans do have a stand pipe in it that allows the level check processes to be accurate. On the Tundra though the pan is just recessed enough for where they want the fluid to be when checked. I only happened to find out when I dropped the pan.

 

8-speed on my 200 has one. It’s plastic.

 

I called around to a bunch of Toyota dealerships and found one that had both of the two different style plugs and the steel crush washers. This is what they told me after looking up my VIN: There are two different style plugs on the bottom of the pan for draining and there is a fill/level check plug up the side of the pan. You need a special fill tool to push the fluid up and into the fill hole. (There is also a YouTube video showing how this is done. The plug for that fill hole is the same as the hex bolt type plug. The other plug is round on the outside and has what is probably an 6 or 8mm recessed hex for a hex key to insert into for removal/tightening. You can see both style drain plugs in the photo I posted.

What I don’t understand is how the pan is constructed, both drain holes are raised above the bottom of the pan. Wouldn’t this leave a lot of the old oil and sediment in the bottom of the pan after completely draining? Would it be wise or unwise for me to get stainless steel flanged screw to replace the drain plugs and be done with the rust? I’d still use the oem crush washers.

Heres a couple pics showing the pan and the flanged screws I’m proposing to use in place of the oem carbon steel plugs.

Thanks.

 

Sorry, somehow I uploaded those pictures twice…

 

I think you are trying fix a problem that doesn't exist.

The plugs will remove with ease. Wire brush them and be done.

Yes, there always is a lot of fluid in the pan. You have to be aware of this fact when removing the pan. You can give yourself an oil bath if your aren't ready.

 

Due to the camera angle your photos kinda suck. That aside, the external hex is the drain plug and the overflow plug is the internal hex. The pan drain may appear that way, but without seeing the internal structure one can't determine exactly how much fluid or debris would remain. Open the fill plug on the side of the case before you drain anything! The fill plug is directly behind the bell housing (a couple of inches) on the driver's side slightly above the driveshaft level. You can fill from engine bay with hose and a funnel or pump in/inject from underneath. As for replacing the plugs...if you want, go ahead, match thread size/pitch and length though.

 

The only “special” tool you need to fill the trans is about a 4’ section of vinyl hose and a funnel. You can fish the hose down between the master cylinder and drivers side exhaust manifold to the fill port.

Pulling the drain gets you about 1/3 of the total fluid out of the system - they weren’t worried about getting every ounce out of the pan. They have magnets in there to hold any floating debris.