I wouldn't worry about the additives. Just use either dino or syn. Let's make sure your knuckle grease is cleaned out of the axle (front) first before spending the $$ on synthetic. The only reason I'm probably going to try a round of full synthetic in the T-case and diffs is to see if MPG is affected in any way...
(Waiting to get your suspension out of my back yard and on your truck... )
Do not use additives in the diff oil, tranfer case, transmission, or motor oil. Buy a good quality oil, you pick, mineral or synthetic, and let the manufacture of the oil supply the additives. If you want to go synthetic gear oil, Mobil 1, Amsoil and Redline are all good.
I use Lucas Heavy Duty Oil Stabilizer in my ...... Junky trucks ie Chevy. I have a very worn pinion bearing, the seal was long gone and sand and pebbles were in the diff and pinion bearing. I should rebuIld but no time. The pinion bearing are very loose in the race. I put in about 50% Lucas.
[quote author=landtoy80 link=board=2;threadid=6510;start=msg53531#msg53531 date=1066790237] I use Lucas Heavy Duty Oil Stabilizer in my ...... Junky trucks ie Chevy. I have a very worn pinion bearing, the seal was long gone and sand and pebbles were in the diff and pinion bearing. I should rebuIld but no time. The pinion bearing are very loose in the race. I put in about 50% Lucas.
Lucas is good for old smokin chevy 350 too. [/quote]
Lucas is not good for your engine, get it out of there. It allows the oil to foam and trap air, and then you get no lube action going on. Instead put a heavier gear oil in. See this link:
That website is amazing. The gear oil pictures are revealing and provide insight into why it's good to stick with the mfrs viscosity recommendations for lubricants. Each gear design, the gear speed, tolerances, clearances, etc determine if the gear lube "climbs" the diff gears in our 80s for instance. Stray from the recommended lube, and you really don't know what you're getting.
This is the reason I am against additives in oil. The manufactures spend millions of dollars per year engineering oils that provide the best protection. The formulas are very exact because they have to not only take into account lube ability but emissions. Here is an example of how exact, this discussion involves the proposal for the new SM oil grade and GF-4 spec:
On Oct. 2, API's Lubricants Committee met by closed conference call to consider a proposal from Ciba Specialty Chemicals Co. regarding the phosphorus limit for API SM. Because phosphorus is detrimental to emissions systems, the ILSAC GF-4 specification limits the phosphorus content of engine oils to 0.08 percent mass, but Ciba's proposal was to cap the SM phosphorus limit at 0.10 percent for all grades.
Ciba's Vince Livoti told Lube Report afterward, "Most of the cars on the road when SM comes out in 2004 will be post-1996 [models], and these cars and their emissions systems were all designed to run on 0.10 percent phosphorus oils. That was the phosphorus level for GF-2, which became effective in 1996, and continues through GF-3, the current quality level. So with all 'S' category viscosity grades, not just ILSAC oils, capped at the 0.10 percent level, the engines and emissions systems for all 1996 through 2003 model-year cars would be protected."
As for emissions systems for the 2004 model year and beyond, which GF-4's 0.08 percent phosphorus limit aims to protect, Livoti reasoned, "Even if all SM oils would be permitted to have a phosphorus level of 0.10 percent, if an oil marketer was going to display the [api] starburst as well as the donut, the phosphorus level would have to be at or below the 0.08 percent level to meet GF-4 limits, thereby protecting late-model cars. So both old and new engines and emissions systems would be protected across the board." The proposal, he added, "has the advantage of simplicity and we've tried to keep it that way in the customer's interest."
The Lubricants Committee disapproved Ciba's "simple" proposal. During the meeting, however, Valvoline presented another proposal - one which added complexity. It called for splitting the lower part of API's donut symbol, so that in addition to being able to claim the "Energy Conserving" label in the bottom half of the donut, marketers who met the 0.08 percent phosphorus limit could make another claim such as "Emissions Compatible" or "Resource Conserving," with the exact label to be formalized later.
When you consider the small changes that are being discussed, you have to consider the effects that adding additives to oils can have. The additive manufactures are concerned about one thing, their pocket books. They have to say that their products improve the oil to make money.
Another example of formulations being carefully designed is Redline Motor Oil. They use very high levels of Moly, which protects in high stress situations where the oil film may break down. The only reason Redline can use the levels of Moly they do is because the Ester Base Stocks they use will support it. Most oils will not. Redline tends to use very agressive additive packages, and they work well. The other side of the Coin is Amsoil uses very low levels of additives, relying on the group IV PAO basestocks, they say they like to rely on the quality of the basestock. While Amsoil does not go the 30,000 miles it claims, it does turn in great UOA numbers on 10,000 mile intervals, about the limit of any oil (note Redline recommends 10,000-12,000 mile, or once a year changes, Amsoil does not recommend going beyond 1 year, even though they claim 30,000 miles). Finally, Mobil 1 is constantly tweeking its formula based on further research and new developments. I think only a fool would try to outguess the research and skills of the lubercation engineers who sole job is to improve the oil quality.