Contour Enthusiasts Group Archives Forums Modifications Transaxle Another MTX fluid option

Jim,

I too have been looking for new gear oil as I have not been satisfied with the Redline MTL to lubricate my Torsen Differential.
I ran Mobil 1 sythetic GL-5 fluid for about a week a little over a year ago and the trans felt great with it AND it was extremely quiet. No noise from the differential in turns.
After being warned to give up the GL-5 fluid due to corrosive properties, I went to Redline MTL. The MTL was much better than ATF but not as good as the GL-5 due to the lack of high pressure additives and it still allowed the diff to make a good amount of noise in turns.
I realize now that I need a fluid with the high pressure additives of a GL-5 fluid but one that does not harm the brass/bronze metals.

I contacted Valvoline and they responded that their synthetic 75w-90 gear oil uses non-activated sulfides in order to prevent corrosion from their GL-5 fluid and should be compatible. Should be wasn't good enough for me so I searched some more.

I looked at Redline and they are claiming their GL-5 gear oil will not cause corrosion as long as the temperature is below 300 F in the trans oil. If it runs hotter then they recommend GL-4 rated MTL which does not corrode up to 375 F.

I looked at Royal Purple and I finally found something in Print that says their GL-5 rated MAX GEAR synthetic gear oil is safe for GL-4 applications or bronze synchro gears.

So I have 3 quarts of Royal Purple Max Gear synthetic Gear Oil, 75W-90 that I am going to try. I got it from a local distributor who is a buddy of mine for $10 per quart.

They also sell it in 80W-90, SAE 90, 75W-140, 85W-140
weights.
It claims to exceed all GL-5 and MIL-L-2105D gear oil specs.

If it performs as good as it sounds, or as good as the Mobil 1 synthetic oil I tried before then it will be a great product that we can be reasonably sure won't harm our transmissions while still quieting down those LSD's.


The HSD GL-5 heavy duty oil in the website you found looks pretty good and the price is right too! It will be another fluid that we should try out.

I'm pretty happy that these companies are coming out and clarifying that their products are compatible with yellow metals.

I know for a fact that a GL-5 oil will protect the differential ring and pinion significantly better than a GL-4 fluid and I'm real tired of hearing those grindy noises in turns from my Torsen. Even though I spoke to Torsen Rick about the noise and he said it was normal, I really hate it.
I'll be sure to post a review after I get this fluid in. It is also cold right now so I should be able to evaluate the cold shifting part as well.

warmonger