Toyota: gear oil smell, tranney, gear oil

Question
Hi
I have a 98 Toyota Tacoma with about 125,000 miles on it. She's got a V6 with a 5-speed manual transmission. About a month ago I was about to go on a fairley long trip with it, and since it had never been done before I thought it would be a good idea to change the transmission oil. I replaced both the transfer case oil, and the tranny oil with regular 90wt gear oil as suggested in the trucks manual. I did not drop the pan, but simply drained the oil out through the plug, and replaced the oil through the top plug til level with the hole. Any overflow I wiped up.
 When I went on the trip, I noticed that whenever the motor/tranney was under stress, (going up a steep hill, or at highway speeds) I got a strong smell of gear oil. I thought it was just some spillage from the recent change, and figured that it would go away, but I also checked underneith the truck for any leaks to be sure, there were none. When I finally got to my destination, (about 700 miles) the smell had not gone away I became concerned and had a local garage change the oil again, which he did with the 90wt oil he also could find no leaks or source of the odor which he said was definetly gear oil.
 When I returned home, and the smell still had not gone, I brought the truck to the local mechanic I've known for years, and he also cannot find the source of the smell, or any leaks. He also aggrees the smell is gear oil, not motor oil, though he did mention that some of the transfer cases use motor oil, not gear oil, he checked and said that mine should use gear oil.
 Now about 2,000 miles since I originaly changed the oil, the smell is still there, if not even stronger. The truck by the way runs and shifts fine.

Any thoughts I'd be thankfull for
Glen

Answer
You ready for the explanation?  The vents to the transfer and tranny are both right on top next to the shifter plate.  Even a SLIGHT overfill of fluid will have the vents going off and expelling the gear oil smell:)  The fix?  Well, check and make sure it's at the right level but even if it is, this is TECHINCALLY normal.

The best fix that I've heard is Redline MT-90 gear oil.  Expensive but smoother shifting AND really helps on the awful gear oil smell.

Hope this helps and sorry for those vents:(
-David D.

P.S.  Maybe a Seafoam tranny additive or Lucas tranny addivtive could help but this is only as a cheap fix.  I'd much rather prefer you upgrade to good gear oil.  Speaking of that though.. what brand and type did you use?