Lexmex

As with the rear differential, we attached a long hose to the filler hole of the transfer case. Since I was the filler person on the rear differential, I couldn't get the same kind of photos as I was getting here, but the process was same except for a funnel you will see later.

Lexmex

Here comes the hose over the top of the engine and one of the volumes of my service manual. You will also note the DRL fuse box that Antonio Jr. made me after the other one fell off and we couldn't find it.

Lexmex

Then my Uncle Antonio in the picture, adds the entire bottle of the Royal Purple with the funnel attachment on to the hose. Just like the rear differential, when we removed the hose, there was a little overspill on top since it takes .9 Liters not .946 Liters.

I should add that on the drain plug of the transfer case, unlike the rear differential, there was no buildup at all.

Lexmex

Any noticeable difference?

Much smoother. I had also changed the tranny fluid (for the fourth time this year via drain and fill but we pulled the front differential plug this time, too).

When I hit the gas, the accelerator pedal seemed much easier to push down than before, no delay of any kind.

TunedRX300

Good job. I had the hardest time to get the drain plug off up front when I changed to Mobil 1 Synthetic 75w90. Claws of Craftsman combination wrench is too thick. AWD is front biased, it makes sense that front gear oil get used up sooner than the rear.

Lexmex

Actually, Antonio said the same thing to me and said it was the toughest one to take off the entire day. He said the rear differential plug have all those filings is normal for the number of miles (had to tell him what it was in kilometers), but he was a little shocked at the smell of the one up front. We don't do too many SUVs as far as maintenance, general just small 4 cylinder vehicles. We have gotten several track guys who come to us for maintenance and other than oil they just never see the importance of the other fluids.

I am actually going to help one of my friends with her Murano (the one whose transfer case broke) by putting in Royal Purple next week, since we have some extra bottles.

TunedRX300

RX AWD is heavily front biased and plus your racing habit generates a lot of heat for the front differential. The gear oil is cooked by excessive heat for a long time and I think better gear oil helps you out more than other owners.
I used a suction gun to draw fresh gear oil in and pump it through the front fill hole. Did everything by myself and save close to $200. Lexus as a corporation probably lose $ on me since I only go there for warranty service and DIY everything else.

Lexmex

One thing I noticed last night and later today (we also had a track day today), was that the RX felt heavy. I didn't notice this before when I did just the tranny fluid only after the rear differential and transfer case drains.

TunedRX300, you are right on the heat and the racing. One other observation is that when my RX got hot after about 6 to 7 runs, the slow times were .1 faster than normal, even on Sunday where it got hot and later humid after a short shower. Thus with the old fluid out, the heat definitely went down.

In addition, I was able to get .500s in the reaction times (including another perfect .500) with impunity since it seems much more responsive as soon as push my foot down on the accelerator.

duane

LexMex,

How did you get the upper transfer case fill hex nut off. It seems to measure out to a 24 mm socket. Did you use a socket, or open end wrench. Don't see how a open end wrench could fit up there to get at it. The lower drain hex nut looks to be 24 mm, but I think you can get an open end wrench on that one.

I had a 4runner that developed a rear axle seal leak. I thought I was going to have to replace the seal. I spoke with a person who had a similiar problem, but he indicated that the differential vent was the problem. I replaced the differential vent (which was plugged), and the seal leak went away. The differential gets hot while driving and needs to vent or it will push out the fluid. The point of my story is that I saw a differential vent on the RX rear differential. Its on the back end up top. Has anybody replaced theirs?

TunedRX300

I used a socket with 10" extension to get the fill plug off, believe me, it is cake compare to the drain plug because you can't find a open wrench with claws small enough to latch onto it. It took me about 10 minutes to wedge my Craftsman to somehow get it off. So better use Synthetic gear oil since Toyota does not have a service friendly design.

Lexmex

TunedRX300 is probably right on as far as the the tool used. I honestly don't remember what we used and everything we have in the shop is practically metric.

In some cases, you wouldn't want to know how we loosen things or do things as we often do things in an unorthodox manner at my uncle's shop, but no damage.

One things I wanted to add is to take it really easy with about 15 minutes of slow neighborhood driving after you changed out the transfer case and rear differential to let the liquid warm up a bit for the first time.

duane

With motivation from this forum, I changed out the rear differential and transfer case fluid. Put mobil 1 75W-90 synthetic. Fluid that came out looked clean, could have been changed before, don't know. Got the transfer case drain plug off with vice grips. Wonder who had the idea of putting a thin thickness drain plug with no room to get a socket on?.

Duane

dwsmith37

Lexmex,

Thanks for the DIY on this rear differential and transfer case. I have learned how to change the oil and the transmission fluid from this forum and I have been waiting for someone to show DIY on the rear diff and transfer case.
I didn't think I was ever going to get the drain plug off the transfer case. The oil that came out the transfer case and the rear diff both smelled bad. Probably had never been changed.

Thanks again,
Daniel

bob2200

I purchased my larger-sized metric wrenches in department stores in Europe, when I was there on business trips. They're inexpensive over there and difficult to find here in the US (one of the last non-metric countries). I haven't found any good stores for this kind of stuff on the islands that the Carribbean cruise ships stop at yet. I guess Mexico would be a good source too, if you are down there on vacation, but I've never been down there.

Lexmex

I looked at my maintenance log book and noticed the relevant information:

15K miles or 12 months, 45K miles or 36 months, 75K miles or 60 months, 105K miles or 84 months, 135K miles or 108 months
Inspect the following:
-Automatic transmission fluid and differential oil
Special Operating Conditions:
-Replace automatic transmission and differential oil

30K miles or 24 months, 60K miles or 48 months, 90K miles or 72 months, 120K miles or 96 months, 150K miles or 120 months
Inspect the following:
-Automatic transmission fluid, manual transmission oil, differential oil, and transfer case oil
Special Operating Conditions:
-Replace automatic transmission fluid and manual transmission, transfer case, and differential oil