Hello Folks,
I searched the forum to find out about when to change my 09 GX470 transfer case oil, as my dealer said it is a sealed unit and the oil never needs to be changed. So it sounds like that was a crock, and I need to change it. My GX now has 80K on the original fluid. What interval do you folks recommend?
Thanks much!

Wierd! My 07 TC is not sealed and serviceable. It has a drain and fill bolts. Maybe dealer was thinking of the tranny. It's supposedly sealed but serviceable. I do my TC and front/rear diff every 50k miles. WS Tranny fluid 100k miles.

Dealers tell you the TRANSMISSION is a sealed unit and not serviceable (not true), but the transfer case is definitely not intended to be treated as such. At 80K miles I would change that fluid for sure, get new crush washers for the drain and fill plugs, make sure to loosen the fill plug 1st, and try tapping the plug with a hammer to flatten the crush washer if you can't get either loose.

Thanks much NTH. I bet that is what the dealer was thinking. I like and am going with your TC and Diffs interval and will do asap. I'll worry about tending to the "sealed" tranny at 100K.

I changed this fluid in transfer case and both differentials. Not a hard job at all.

The dealer should have a 4x4 driveline service package, which is the gear oil in both diffs, the transfer case, and greasing the zerk fittings.

This thread might be useful:

https://www.clublexus.com/forums/gx-...id-change.html

Chip H.