Royal Purple Gear Oil

[SteveV]

A number of you have said that in addition to putting Royal Purple Synchromax in your Tremac, you also replaced the gear oil in the rear axle with Royal Purple as well.

What weight did you use? I have seen 75 - 90, 80 - 90, 75 - 140 and 85 - 140.

Thanks in Advance...

[PsychoZL1]

I used the 75W-90 Royal Purple Max Gear. Works great and it's the recommended gear oil weight for the rear differential.

[Deebo]

My '10 SS started making noises immediately after I changed my diff gear oil to 75W/90 Royal Purple. I later went back to my old stand-by, Mobil1, and the noises ceased. I was later informed that, contrary to Royal Purple's claim, a friction modifier needed adding when using their product (?)

[SteveV]

Originally Posted by Deebo

My '10 SS started making noises immediately after I changed my diff gear oil to 75W/90 Royal Purple. I later went back to my old stand-by, Mobil1, and the noises ceased. I was later informed that, contrary to Royal Purple's claim, a friction modifier needed adding when using their product (?)

That is good to know. Thanks.

[White_SS/RS]

Originally Posted by Deebo

My '10 SS started making noises immediately after I changed my diff gear oil to 75W/90 Royal Purple. I later went back to my old stand-by, Mobil1, and the noises ceased. I was later informed that, contrary to Royal Purple's claim, a friction modifier needed adding when using their product (?)

//Update: see post #9.// Thats interesting, I just changed my diff oil to 75/90 RP and haven't heard any noise. I didn't add any additional friction modifier either. I suppose each car is different.

[wpl11972]

The syncromax has limited slip in it. I've had no problems with it

[SteveV]

Wait, I thought the tranny fluid was called synchromax. The rear gear oil is called Max-Gear...

[jcamo]

Thats correct .....stevev

[White_SS/RS]

Originally Posted by Deebo

My '10 SS started making noises immediately after I changed my diff gear oil to 75W/90 Royal Purple. I later went back to my old stand-by, Mobil1, and the noises ceased. I was later informed that, contrary to Royal Purple's claim, a friction modifier needed adding when using their product (?)

Originally Posted by White_SS/RS

Thats interesting, I just changed my diff oil to 75/90 RP and haven't heard any noise. I didn't add any additional friction modifier either. I suppose each car is different.

Update: At first I wasnt having any noise with the royal purple, for about 200 miles or so, and I dont hear anything when driving around but I am getting a pop from the diff when I back out of my driveway, does it almost every time I leave. I figured I'd add more friction modifier to the diff (3oz, which is half what the bottle recomended)... still does it..... I'll try adding more and see if it helps, but sounds like I'll be switching brands.

[SteveV]

I replaced all 3 of my primary drive fluids with RP Friday, 11/29:
- Max Gear 75w90 in the diff (didn't need to add any additive)
- Synchromax in the tranny
- Royal Purple 5w30 in the Engine.

The shifting has smoothed out quite a bit. No noise out of the diff.

Put 150 miles on her this weekend after doing the fluids on Friday. Running great.

[h018871]

Steve,
A related question: my trans makes noise when the clutch is engaged and in neutral. Not when cold, always once warm though. Did yours have that noise? If so, did the RP eliminate it?

[SteveV]

Unfortunately, No. My tranny never made any noise with the clutch in.

Before the Synchromax, it was a little clunky in the 1-2 shift. That is gone now.

[h018871]

Thx Steve
I'll give it a try anyways at the next fluid change
I misspoke earlier, by clutch engaged I meant "foot off of the pedal"

[jcamo]

Originally Posted by h018871

Thx Steve
I'll give it a try anyways at the next fluid change
I misspoke earlier, by clutch engaged I meant "foot off of the pedal"

...... That sounds like the throw out bearing your hearing.