i thought i saw a post around here about what fluids are the best to use. i want to run full synthetic in both the t-case and front diff. whats the best brands and weights to use?
thanks,
mike

Don't use Redline. Chuck had problems with it. He's the guy to talk to about synthetics, but hopefully he'll post here so others can gain from his experience.

I have an automatic tranny, and switched to Mobil 1 ATF in the tranny last year. I switched to Mobil 1 ATF in the transfer case earlier this year, and have had no problems at all.
The transfer case can use Dexron-III/Mercon compatible ATF or GL-4 oil, the rule of thumb seems to be use ATF if you have an automatic, and GL-4 if you have a manual. In other words, same type as in the tranny for the t-case.
For the front diff, I have Mobil 1 75W90 for over a year, no prob.

Brent

Just a quick note. If you are running an air locker it will blow a small amount of that expensive synthetic out the exhaust port of the solenoid. Also if you drive regularly in water and have to change gear lube and repack bearings synthetic gets kind of expnsive as well. If not, go for it and have fun.

Off topic but I noticed you are running a brush guard Gordon. Is that still the case? You might want to chat with Bluztraveller aboot that....:cool:

Cheers

i had the transmission fluid changed awhile back at the dealership (manual trans). i have plenty of mobile one full syn atf fluid in the garage (other vehicle is auto). the trans and t-case don't share fluid do they?? if they don't, i'll use the mobile 1 atf in the transfer case and change the tranny fluid in a couple months to mobile one.

They are two separate units, so they don't share fluid. I use Dexron III in both the auto transmission and transfer case. The owner's manual is somewhat confusing on this issue as it indicates gear oil on one page and Dexron III on the fluids chart on another page.

Yeah, Redline BAD!!!

I still have the Redline D4 ATF in the transfer case and it's fine, but I wouldn't use Redline in the differentials or the gearbox if you have a manual. I switched to Amsoil in the rear differential and the gearbox and everything is fine again. Amsoil Series 2000 75W-90 gear lube is what I used.

Use ATF in the transfer case whether you have an automatic or a manual. As Scott mentioned, the owner's manual gives you two answers, but three different Nissan service departments told me ATF. Since then I have heard that Dexron III/Mercon ATF is a GL-4 lubricant, but I'd just use the ATF and be sure. :)

I know quite a few people are using Mobil 1 in the manual transmissions, but keep in mind that Mobil 1 is a GL-5 lubricant and the Xterra calls for GL-4. Nobody seems to be having any problems, but I'd consider warranty issues and such. Almost all synthetics are GL-5. Only Amsoil, Redline, and I think Royal Purple are GL-4 rated.

FYI, Redline 75W-90 gear oil made my rear differential howl like you wouldn't believe when cold. So loud I could hear it over the stereo. Redline MT-90 gear lube (which is what is specified for the Xterra) made shifting impossible; especially when cold. It was so bad I often couldn't engage several gears for 5-10 minutes in the morning. I've heard the Redline MTL works OK, but it is a lighter weight oil and not recommended for use in the Xterra by Nissan or Redline.

And don't ever, ever, ever put Valvoline SynPower synthetic brake fluid in your truck! Trust me, I learned all about it the hard way. Ever change out the brake or clutch fluid use Castrol GT LMA. Not related, i know, but figured I may as well mention it.

Good luck!

Nice post Chuck. I should add that to the FAQ or something.

Originally posted by ozxterra
Off topic but I noticed you are running a brush guard Gordon. Is that still the case? You might want to chat with Bluztraveller aboot that....:cool:

Cheers

No one on this board or any other has an idea what I am running now. I haven't posted info or photos in eons and it no longer resembles what it once was. You will just have to keep guessing.

Uhhh ok? I will be sure not to hold my breath....:rolleyes:

http://www.neosyntheticoil.com/75w90rhd.htm

Does this look any good? It is available at Four Wheel Parts.

Also just found this on the same website...

http://www.neosyntheticoil.com/offroad4.htm

I was trying to research what the difference was in the GL specifications. One thing I noticed is there seems to be a break between GL-4 and GL-5, one source said GL-1 through 4 were for anti wear and GL-5 and 6 were for high pressure applications. For that reason I would be carefull when substituting GL-5 for the Xterra. Also another source said that you should not substitute up or down on the scale.

According to the Pennzoil crowd (who, by the way, supply the original fill for the LSD diffs and manual transmissions):

“The extreme pressure (EP) additives in most gear oils contain sulphur-phosphorus compounds that can be corrosive to certain “yellow” metal components, such as copper and brass synchronizers.”

Since the FS5R30A 5-speed transmission contains brass and bronze parts, GL-5 is a big no-no.

Richard.

No - I don't own Pennzoil shares, work for them, or anyone else in the oil business...