Super Tech Gear Lubricant SAE 80W-90 and yellow metals?

[jbclem]

Is the Super Tech 80w-90 GL-5 gear oil aggressive against yellow metals such as syncros? Does it have high, medium, or low levels of EP additives? I'm looking at it because it's cheap and I have an old leaky VW beetle trans so I don't want to fill it with the expensive stuff. I can also get it shipped and in Covid times than means something. I've been using MasterPro 80w-90 GL-5 from Oreilly but they don't ship it and I don't know if it's any better or worse than the Super Tech 80w-90 GL-5.

Any thoughts?

 

[Propflux01]

Supertech lists as GL-5 only, I do not believe it is GL-4 safe. This is what should be used in that tranny:

Amazon.com: Sta-Lube API/GL4 Multi-Purpose Gear Oil 85W90 SL24229 – 32 Fl Oz, GL4 Hypoid Gear Oil for Corrosion Protection : Automotive

Buy Sta-Lube API/GL4 Multi-Purpose Gear Oil 85W90 SL24229 – 32 Fl Oz, GL4 Hypoid Gear Oil for Corrosion Protection: Gear Oils - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[slacktide_bitog]

Most gear oils sold in stores are NOT appropriate for manual transmissions.

The best choice for your Beetle would be Valvoline Professional manual transmission fluid. Part number 508216.

If you would rather buy from a store rather than online, go to Napa and get Liqui Moly 20012.

The aforementioned L-M and Valvoline products are the only 75w90 gear oils suitable for synchronized manual transmissions that are reasonably available in the US. You can try something thinner such as Pennzoil or Valvoline Synchromesh, which are more widely available. NOTE: the Valvoline Synchromesh is NOT the same fluid I linked to earlier in this reply.

Why is it leaking? Aren't those old Beetles really easy to work on?

 

[Bjornviken]

Is the Super Tech 80w-90 GL-5 gear oil aggressive against yellow metals such as syncros? Does it have high, medium, or low levels of EP additives? I'm looking at it because it's cheap and I have an old leaky VW beetle trans so I don't want to fill it with the expensive stuff. I can also get it shipped and in Covid times than means something. I've been using MasterPro 80w-90 GL-5 from Oreilly but they don't ship it and I don't know if it's any better or worse than the Super Tech 80w-90 GL-5.

Any thoughts?

I am running gl-5 in my transmission without any problems (Toyota Rav4). Dont think oil is agrresive against yellow metal. That was years ago

 

[jbclem]

My understanding is that GL-5 has more EP additives than GL-4, and the amounts of the sulfur/phosphorus additives are what determines the agressiveness against yellow metals. Apparently some GL-5 gear oils have less EP/sulfur phosphorus additives than others. So does the Super Tech fall into this less aggressive category? I'm asking because I don't know where to find this information.

 

[mazdamonky]

I drive mostly Mazda's all of which state to use GL4 or GL5, but it must be yellow metal safe. I have yet to find a GL5 that has been yellow metal safe and does well in these cars. The only yellow metal safe I have found in stores around here is the Royal purple 75w90.

I generally just purchase Redline MT90 off of Amazon at a good price or straight through redline themselves. It works fantastic for anything that needs 75w90 or 80w90 that needs to be yellow metal safe.

 

[jbclem]

Here's some interesting information I found on a tractor forum:
..."I did some research on this gear oil thing and even made phone calls to the manufacturers. The sulpherized EP additives are what can attack bronze, brass and copper. That said, they're virtually all chemically buffered so as to not do that. Now in particular, if you can find "MT-1" somewhere on the label then it is definately buffered so as not to attack soft metals. The "MT" stands for manual transmissions and the buffering protects the synchronizer rings."

The Masterpro gear oil I've been using is MT-1 rated. Does anyone know if the Supertech 80w/90 is?