14 Tundra 5.7/Schaeffers 75w90 293 gear oil 58k miles
- Thread starter Sumo91
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Your wear metals are well under normal condemnation limits for gear lubricants, viscosity in grade, looks good to me.
I appreciate the reply. I was curious about the wear metals (thinking they're high based on blackstones comments) but this is the first gear oil UOA I've ever done. All others have been engine and trans.
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Deleted member 89374
Also, consider that 366 ppm of Iron means the gear oil is very good at dissolving small Iron particles. That's all. I wouldn't lose any sleep over it. Schaeffers makes a good product.
That's good to know. I'm not worried about anything. I was just curious about the report. I wanted to post it up because I wasn't able to find any UOAs on Schaeffers gear oil with a search on here or on Google.
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Deleted member 89374
Thank you for posting it.
Short of taking your differential apart, taking measurements, and comparing them to factory specifications, there is no way to infer wear from a UOA.
For example, if you look up AMSOIL SEVERE GEAR UOAs, you will see that they tend to show very low Iron numbers. Does that mean that SEVERE GEAR is a better gear oil? Absolutely not. At the opposite end is Red Line, which shows high Iron numbers, just like Schaeffers. Still, many enthusiasts and racers use and trust Red Line gear oil. That's why UOAs can't be used to infer wear.
Now, if you see triple-digit wear numbers for motor oil UOA and four-digits for gear oil, then it might be good to take a closer look inside.
I found this post for a VOA on the Schaeffers gear oil, but it's from 2009
The TAN is 2.7 in the VOA, interestingly enough. What would be the limits on the TAN before needing to be changed? I've read anywhere from double the original number, to quadruple the original number.
Schaeffer's 293 75W-90 GL-5 Gear Lube
Sampled from a recently purchased, previously unopened 5 gal pail via suction pump. Analysis by Polaris Labs. Si-----27 Na-----1 K------2 Mo-----351 B------103 Mg-----10 Ca-----162 Ba-----2 P------1048 Z------66 All others 0 Water=
bobistheoilguy.com
The TAN is 2.7 in the VOA, interestingly enough. What would be the limits on the TAN before needing to be changed? I've read anywhere from double the original number, to quadruple the original number.
