Front Diff and Transfer Case Oil Change Howto

Yikes any tips on getting the fill plug off? It's in a really tight position and is pretty rusted.... I can use an Allen key and tap it into place with a hammer for the drain plug which is in similar shape. However for the fill plug there is very little room to work... Thoughts?

 

A 50/50 mix of acetone and ATF has been my go to for rusted parts, works wonders. Just don't apply fire immediately! A heat gun on low might work, but I stick to a hammer and that mix.

 

You are going to need a 24mm socket and 3 inch extension. Preferably a 6 point socket will do the best job. If that doesn't take it off easy spray it with PB blaster over the next 2 days2/3 times a day. that will help break it free and then the socket will be able to take it off. These plugs are made of really cheap metal and strip easy. Do not strip it out and do not drain first.

 

Here is a pic of the fill plug for the front diff... it looks like in only accepts a hex key not a 24mm socket... even with the skid plate off there is no room to tap the hex key in. I've sprayed it down with penetrating fluid a few times today... I'm going to try and clean the plug with a wire brush dremel attachment.

 

you want to clean the *corners* of the hex hole so a bit gets a good bite. a spinning metal brush will just polish the center of the flats.

I do believe I'd be using several rounds of AeroKroil, and a sacrificial hex bit in and out til it fits in easily, then use a fresh one to actually remove it. and have a new plug on hand. I'd also clean the whole face of that with a wire brush before I even attempted to remove it, so you don't get rust inside.

man, thats a lot of rust. my 1964 ford rat truck doesn't have that much rust. so glad I don't live in the rust belt.

 

2010 Tacoma
Wanting to change each fluid, front diff, t-case, manual trans, and rear diff.

Mobil synthetic 75-90 for everything? My store only has 75-90 LS but my rear diff is not limited-slip. Will that matter?

*My truck is missing it's owners manual

 

Download an electronic copy.

 

Great write up this will save me a lot of time. I've only had my tacoma 2 months 85000 mi .working my way through all of the maintenance before I start the mods

 

So I thought I'd do a followup for anybody that this happens too. I overtightened my fill plug. Got the old one out and bought a new one. Re tapped the threads (Marlin Crawler). Trick here I learned is to fill the gaps with loads of grease to catch shavings that may occur. Worked great, came out with a few. New plug threaded great but still had a slight leak. After multi-state trip I took a look to see how much had leaked out. Lost about .2-.3/qt. Bought another qt and put teflon tape around threads this time and cleaned cover as much as possible. Coated with flour to make it easier to tell if anything was leaking. So far after 1 week and about 100 miles in 100+ degree temp all is good. No leaks.

 

Very useful thanks for the outstanding write up

 

Did some maintenance at 23,323 miles.

Changed my rear differential, front differential, and transfer case oil to Mobil 1

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90. Front and rear diff oil was very black with very minor/thin shavings on the magnets.

Transfer case oil was honey-colored (expected).

Also changed my air filter and cabin filter.

Summary: change your differential oils earlier than the recommended 30,000 miles.

Check out the DIYs on here by @chris4x4 and @boogie3478 to save yourself hundreds of dollars (close to $1,000 for all 3 services).

The dark oils smell like death.

Drink beer and have fun.

 

Did the three part oil change like kitsym and used the Mobil 1 oil. I found you can get by with a 15/16" socket (I use my impact socket) to remove the hex head plugs. The front differential needed the 10mm allen and I used that with a 3/8" ratchet without issues. I don't off-road my truck like a lot here so the plugs weren't dirty, rusty etc. and the truck is only 3.5 yrs. old. I also found a washer kit on Amazon for about $14 but didn't really need them this time.

 

Nice!

How'd your front/rear oil look?

 

Considering normal driving, not bad at all. A little dirty by new oil standards, but overall very pleased. The front/rear were more "colored" and the transfer case was as clean as new oil. Not the overall stink as some say, and I was in the industry for 40 years. Still smelled better than the fish oil based gear oil in a lot of new vehicles. Magnets had very fine metallic residue you'd normally find in a oil change. Overall it's ready to go another 35k!

 

I got a set of impact sockets from Harbor Freight tha contained 24mm deep well. Worked great!

 

i change 15k to 20k depending on how many trips i do.....and i also buy in bulk now to save $$

 

This was a huge help!! Cant believe how easy it was and how much $$$ I saved!!!

 

Last time I had my truck in they said I should change the fluid in the diffs and transfer case soonish. Last time I did it was at 30,000 miles and now it's at 53,000.dont know if they actually looked at the fluid in there or just recommended based on mileage, but my oil just came, so will be using this write up again in the next couple weeks. Might as well do it before the first snow.
Thanks for saving me a few hundred bucks!

 

did this shop KNOW you did it at 30K? If not, they are probably thinking its original. I did mine at 24k miles because it was 8 years old ... I don't plan on doing it again until close to 100K.

 

Yeah I told them I did it and their mind was blown that someone did their own maintenance. (it was the dealership)

Either way, I went ahead and decided to do it today. Only hiccup was that I couldn't get the washers off the transfer case plugs to replace them, so those washers are on to round three. It was almost like they were too small for the threads on the plug.