Front Differential Drain Plug Saga

Long time stalker, first time poster on TW. Just thought someone may be able to learn from my absolute self induced nightmare of a differential fluid swap..
So there i was, thinking hmm.. “youre getting close to 200k, might be a good idea to do a complete reset of fluids and basic maintenance” all was going swimmingly until i got to the front diff..
(i don’t know which engineer at toyota was on vacation the day they decided to make the drain plug up front a 10mm hex but i hope that guy stubs his toe every day for the rest of his life)
like any good wannabe DIY mechanic i ensured i could loosen the fill plug prior to the drain plug..

Step one : Strip the ever living crap out of the bolt.


Step two: gouge the plug with a cold chisel after applying heat.


step three : completely snap off EZ Out bit in drain plug (ensure you puncture all the way through to the diff. So now you have no option but to win this war) The magnetic chip cap was still attached THANK GOD


Step four : do a terrible job welding a nut on the bolt (forget to leave the fill plug in so the heat causes the inner Diff seal to explode)



Step five : remove stuck drain plug and replace with GENUINE LEXUS GS460 IS250,350 (06-21) FRONT DIFFERENTIAL DRAIN PLUG 90341-24016
comes with a 14mm socket head



Follow on steps : Replace inner Diff seal and throw on a new CV axle… because who’s isn’t leaking a little grease anyway…

To wrap it up with a bow… don’t be an idiot like me.. and honestly swap out that plug for the Lexus OEM one at your earliest convenience..

 

I can see why this happens but I didn't encounter any issues during my 1st drain. That being said, I used a decent quality 3/8" hex socket with sharp splines. The issue with hex is that you can assume the bit is all the way in, but in reality it is only about a 1/16" or so and then once you start rounding things off it's a hole to hell.

 

I done it now. Just thinking the thought of saying it’s been awhile since I’ve had a saga type task. Too late, I’m jinxed, it’ll be coming, I already know.

 

I stripped mine a few years ago and got it out with a bolt extractor. Interesting lesson about the impacted of heat from the welding on a sealed unit. Thanks for posting.

 

Impact driver, great tool for things like that.

 

before i found about the Lexus version i bought one of these. Also has a large hex drive

https://drainplugmagnets.com/cars/toyota-lexus/

 

Very informative 1st post... thanks for sharing and welcome aboard!
I went a different route. Had a shop break the plugs loose for the 1st time and install the Lexus plugs afterwards... less stessful.

 

Since i changed all the fluids around 1000 miles all the plugs came out easily. For the front one I cleaned it out the best i could using a couple of q-tips and a shot of compressed air.

If you are planning to switch to the lexus style and worried about the allen key style stripping what about cleaning it out well and using epoxy to hold an allen key socket in there ?

 

I replaced my front drain plug after the first time I changed the fluids. My only concern for the op, is the 200k before the first change??? You should be changing the diffs and transfer case every 15000 miles or every third oil change. The plugs should be every 30000 miles. You should change your oil every 5000 miles, grease the zircs and inspect / change the air filter / cabin air filter.

Apologies if I misunderstood the original post.

 

The only way this happens is if the Allen isn’t inserted all the way. However, it can be hard to see, vs a socket that you can easily see if it is all the way on, and rust inside the hole makes it worse

 

The Lexus plug is superior for sure, way more relaxing changing fluids haha.

 

Like many have said, this typically happens when the Allen can’t insert all the way. I always scrape the inside of the plug with a pin and then use air to ensure there’s no debris that might keep the Allen from seating fully. Was yours dirty??

 

Transfer drain plugs here

https://trailtoys.net/products/magnetic-drain-plug

 

That is way overkill on front diffs and transfer case. Did the rear at 1500 miles and it needed it. Did the front and transfer case and the fluid was pristine. Had already bought the amsoil gear lube but in reality they didn't need it. I did replace the fluid in the front diff 5000 miles later but only because I replaced the drain plug with a hex design to replace the original 10 mm allen. Even then it was clean and clear.

From amsoil and normal service (I am running severe gear 75w90)

Drain at 100,000 miles
(161,000 kilometers)
of service or according
to the owner’s manual,
whichever is longer.


Severe service is listed as 50,000 miles

Front diff even though its a ring and pinion like the rear experiences little to no wear since its not engaged until 4wd is selected so in my case less than 5% of the time rear is (winter). And the transfer case is almost a straight thru transfer of power and and the gear setup is more like a manual transmission.

 

You do you. I'll continue to replace the fluids at the intervals I stated above.
The relatively low cost of fluid is such a minor consideration in the long term ownership costs, it doesn't even hit my radar. 6 quarts of amsoil severe gear is what, like 100$. Cheap, prevention if you ask me.

 

Perhaps you mean 15,000?

 

don’t get it. It’s not high torque.

if you want heat it. Spray penetrant. Tap it with a hammer.

seat a good fitting high quality bit into it and break it loose. That’s what professionals do working on other cars every day that have lots of Allen bolts without issue.

Allen bits from someone like Sunex, GP, SO, etc is going to fit better and avoid stripping over something like cheap made in China crapsman.

tried to type craftsman and autocorrect put “craving a man”. Even autocorrect knows.

 

I changed mine every 20 000 miles until I realized I was wasting money. If it doesn’t get water contaminated a well broken in diff can go damn near forever on top shelf synthetic.

 

Nope. I did rear diff at 1500. looked like a metallic silver milkshake. And IMHO this cant be good for diff bearings and axle seals...Also replaced the allen drain plug with stainless magnetic hex.

 

Agreed. Wont hurt anything and the only damage is to the wallet.