My local Toyota dealer actually sold me 80w-90 and when I asked about the 75w-85 they told me the 80w-90 is what they use in their fill guns. So I am pretty sure 75w-90 would be totally fine.

I changed the oil in both of my diffs at 30k and there was a large amount of metal particles on the drain plug magnet and suspended in the oil itself. Changing it at 35k certainty wouldn't hurt. I used M1 75–90 synthetic.

See: http://www.toyota-4runner.org/5th-gen-t4rs/78892-transfer-differential-oil-change.html

I noticed a couple drips on my driveway this afternoon so I decided to crawl under and check all the bolts. Either my transfer case fill was not tightened all the way, or it came loose in the 200 miles I have driven. I would guess that the beer intake played a factor in that I would guess that the angle of my driveway is what allowed the drops to leak through the fill.

I went ahead and checked the tq on all the bolts and fluid levels since I was under there. Everything was fine outside of the loose transfer case fill. I left the aft skid off because my 3/8" tq wrench is in in lb not ft lb and my 1/2" to 3/8" adapter is apparently snapped off. I sprayed everything down with degreaser so I can spot any leaks if there are any, but I would say it should be fine.

I run 75W90 non-LSD synthetic, it's fine - it's the number before the W that's more important than the number after. I have a sample of the oem fill to send off to Blackstone, and I'll do the second change too, and then I'll know for sure.

What fluid are you guys running in your transfer cases? I'm going with Amsoil 75w90 severe gear in the diffs

Thanks

I'll be going with the cheaper of the 75W90 Amsoil products - this isn't a differential or transmission on a tractor, either semi or farm.

This is mainly because of price and convenience - it's cheaper than most other synthetics by the gallon, and as it turns out you need pretty much exactly a gallon for the diffs and i think half that for the transfer case. Being able to add a pump to a gallon can, rather than the squirt bottles, is the convenience part of this equation.

I have used the Severe Gear in the past and am comfortable with it. I can't imagine that I'll miss the additional $20 it will cost me compared to the cheaper stuff. I'm sure both will be good though

Thanks for the great write up. I searched for the part #'s for the transfer case gaskets in this section but no luck!!! Going to the dealer tonight to pick up oil element kit, drain plug gasket and differential gaskets I have all the part #'s for those thanks to this write up. I'm sure the dealer has the #'s but I like to be sure I'm getting the correct parts. Thanks!!

Went through the RM manual and can't find a drain plug for the transfer case, only filling. I'm also to use the same GL5 fluid as the diffs as well? Quantity in litres?

Cheers.

*Not being a smartass* Do you know where the transfer case is? If not, dead center of the truck. The bolts stick out like a sore thumb. Takes 1.6L IIRC, just fill until she runs a slight drip out and you're done. I used the same fluid in all three. Cost me a little in the MPG department I am sure with running the heavier weight in the transfer case (I believe it calls for straight 75w) but it is just fine. There is a thread floating around the 4G forums that show the TQ specs and location for the transfer case, I will see if I can find it and link you.

Appreciate the info. I haven't crawled under there yet to take a look but sounds like it should be easy peazy.

Great write up. Thanks

I believe the fill/drain gaskets are 90430-18008

Thanks for the info. Just did my rear diff today but didn't have a 10mm allen for front. will try again tomorrow.

Thanks again.

what will happen if you use 75w-90 synthetic? I used this in place of the 75w-85. A guy from an oil change company just told me I voided my warranty. I plan on Towing tomorrow and am a little concerned.