Best synthetic gear oil?

[TGP]

I just recently purchased a 97 Jeep Grand Cherokee and want to change all the gear oil. I believe I am supposed to have 75w140 with the quadra drive 4 by 4 system. I've read lots of posts; some people like RL, Amsoil, RP, etc. What should I go with? Thanks in advance for any input.
TGP

 

[AstroVic]

I will definitely vote for the Royal Purple!

I run RP 75W90 in all four of my 8.8 Fords and I will never run anything else. (Redline is also an excellent choice, but I'm going to personally stick with RP.)

 

[Bror Jace]

TGP, I don't think you'll find a consensus. Everyone has their favorites and unlike motor oil where we post UOAs, not enough testing has been done to clearly show superiority of one brand over another.

My pick? Red Line Oil or Schaeffer.

Do a search on the word "synthetic" in this subsection to see past threads where this is discussed.

--- Bror Jace

 

[Motorbike]

Some of these lubes are only regionally available due to distribution practices .

Citgo
Mystik
Phillips
Conoco

Have some high end synthetic gear lubes that one can't go wrong with .

No group III's in those unlike some .

There is an independant company named Summit out of TX that has a couple nice gear oils .

 

[VaderSS]

quote:

---

Originally posted by Motorbike:
Some of these lubes are only regionally available due to distribution practices .

Citgo
Mystik
Phillips
Conoco

Have some high end synthetic gear lubes that one can't go wrong with .

No group III's in those unlike some .

There is an independant company named Summit out of TX that has a couple nice gear oils .

---

Do you know of a synthetic gear oil that uses group III? I know that there are some who are interested in finding such a lube, since the friction type LSDs prefer mineral based oils.

 

[1sttruck]

If you're looking for the 'best of the best' you'll need to compare oil test results in similar applications over extended periods, ideally with your specific vehicle. If you're looking for something that will work fine there's a variety of products available. I use Mobil 1 75W-90 in both axles of my truck as although it's a bit expensive it's still about half the price of the dealer oil, and hasn't seemed to generate too many complaints about wear, cold or hot weather operation, and use in longer drain intervals. Amsoil seems to have similar attributes. Redline seems like it has some problem here and there, and based on some comments is possibly not the best choice for extended drain intervals.

 

[Tremo]

Dunno about "best", but it's hard to go wrong with RP, Redline and M1.

 

[1maniac]

I like Redline, and Amsoil S2K. I don't feel you get what you pay for with Mobil-1 Gear Lube.

 

[hatcoleman]

I just replaced fluid in my Ford F150 and Toyota Sequoia. Both call for 75w140 full synthetic.
Purchased a case of Royal Purple. Had to order it,locally only found Coastal. And the Royal Purple was about $3.00 a quart less than Coastal.
Had used Coastal in same Ford F150 and had experienced oil foaming. Gear oil would come out the vent tube.

 

[sprintman]

NEO would be hard to beat IMO. F1, CART etc use it a lot.

 

[tdi-rick]

now you've really surprised me Sprintman !

I opened this thread fully expecting a Redline recommendation.

Rick.

[ August 07, 2004, 01:45 AM: Message edited by: tdi-rick ]

 

[Greaser]

Have been using Pennzoil synthetic GL-5 in various Jeep vehicles(do service on 6 Jeeps) with good results thus far..it is easy to find,fairly inexspensive and comes in 75W-90 and the hard to find 75W-140 (Jeep Rubicon uses this weight in front and rear Dana 44's)