What size allen hex wrench do I need for the rear differential? Is the filler and drain hole both the same size?

Also what size socket do I need for the transfer case? I tried 19mm on the filler hole (the largest size I have) and it was still too small? Is the filler and drain hole the same size?

 

"What size allen hex wrench do I need for the rear differential? Is the filler and drain hole both the same size?"

10mm for both

"Also what size socket do I need for the transfer case? I tried 19mm on the filler hole (the largest size I have) and it was still too small? Is the filler and drain hole the same size?"

15/16 or 24mm they are so close that you really can use either one. Use a socket for the fill and an open end wrench for the drain. I got a 15/16 from Ace Hardware (their house brand) and it fit fine.

 

THANK YOU! will be purchasing it tomorrow then.

off topic but is the front differential and tranny the same 10mm allen hex wrench as well?

 

Yep, 10mm for all of them. Make sure to pick up some new crush washers if you are doing the transfer case or rear diff.

Part #'s are here: https://www.clublexus.com/forums/sho...d.php?t=326550

 

Thanks for the heads up! Will definately replace the washers as well then! THANKS again!

 

Let's once again revisit the transfer case and rear differential.

This time around I want to focus on certain difficult areas in the process that have been troublesome areas. I actually had to solicit some help on one thing from some old auto friends that I knew long ago when I first lived in Miami.

Let us take a look at possible tools that can be used in this process.

This time around I went with Royal Purple MaxGear 75W90 fluid, since I now have access to it again in the U.S., while we ran out of it in Mexico. I have to say that after using the Pennzoil Synthetic the last time around, I was not entirely pleased, but I will get to that at the end, as it did have one positive.

You need 2 bottles. (1 quart or .946 ml in each) as the transfer case holds .9L and the same goes for the rear differential.

You will also note a vise wrench and vise grip wrench that could come in handy at the bottom.

On the far left is a torque wrench. Now, I do not torque anything by the numbers, I merely hand tighten it as much as possible, but the bar itself is useful to get off troublesome bolts, in particular the transfer case filler bolt.

We also see a hand pump. These things are cheap and are available at any auto parts place. I had some difficult with using this, but there are other alternatives as other members have already shown. This is merely an example.

We also have a socket wrench with a 6 inch extension. The big bolt at the end is a 15/16ths inch, though one can use a 24 mm. I prefer the english unit wrench because it is a bit tighter. 15/16th inch = 23.8125 mm but it will still pull off the transfer case filler bolt with no problem.

Also shown is 15/16th inch open wrench. There is a good reason for using an open and not closed wrench as we will find out in removing the transfer case drain bolt/plug.

Also seen is 3/8th inch hex wrench, though one can use a 10 mm one. 3/8ths inch = 9.525 mm. That is used to remove both the drain plug and filler plug on the rear differential.

One sometimes needs to get torque on the rear differential filler plug and I use the socket wrench again with a tiny 3/8ths bolt so that the hex wrench can fit inside in order to help serve as a fulcrum to get it off.

Also helpful, but not really necessary is 3/8ths inch open wrench.

By tradition, will show the rear differential first, though I actually did the transfer case first in real time.

 

Here's the rear differential.

The yellow circle is the drain plug while the blue circle is the filler plug. Both use a 3/8ths or 10 mm hex wrench. The filler plug faces the rear passenger side wheel.

 

The filler plug should come off first (no need in draining it out if you can get the filler plug off first).

Now, here's a common goof up. One can't access the filler plug because part of the rear axle is in the way. So you need to move the vehicle a slight bit forward or backward so you can access the plug.

 

Now we can get to it.

 

Now we need to get the hex wrench into the hole on the filler plug.

 

Now, it may or may not come off with a simple tug of your hand.

If it doesn't, one can use the socket wrench with the 3/8ths inch attachment to lock on to the bottom of the hex wrench as shown. You want to grab the wrench with your hand just underneath where the hex wrench meets the socket wrench so you can push up and push in order to move the bolt in counterclockwise direction as if you were facing it.

 

Once loosened you can turn it with your fingers and then pull it out.

 

Then time to attach the drain plug.

Again, one uses the 3/8th inch hex wrench. This shouldn't require to much effort (pushing your foot on it for extra power can be used). Rotate it counterclockwise until loose and then use your fingers to slowly turn it and pull it off, but make sure you have your drain bucket underneath.

 

And here come the fluid.

 

Normally, there is accumulation on the magnetic part of the drain plug, but this time there was little to any. The last picture in the set is with the drain plug fully cleaned off.

This is one area where the Pennzoil Synthetic did really well. I'd probably also have to add that I had no leaks here at the rear differential.