Just drained the Valvoline rear diff 80W90........

[aquariuscsm]

...........and it came out almost black. Hasn`t been in there very long (maybe a few months?). I`m replacing it with Amsoil Gear Lube 80W90. Why did the Valvoline 80W90 come out so black looking? The original rear diff lube looked brand new when I drained it awhile back (had 50k-ish miles on it). Was the Valvoline maybe not protecting as well? Anyway,I`m super anxious to pump the Amsoil in there!

Something else I noticed about the Valvoline gear oil bottle (I had a half quart left over from when I had installed it) is that it has small flakes of something or other floating around on the bottom of the bottle.

 

[Jimmy9190]

Was it synthetic? I am very interested in this since I am about to drain and refill my manual transmission and rear differential fluids and was considering using Valvoline Synth but it's 75w-90.

 

[aquariuscsm]

No,it was the dino Valvoline 80W90 (white bottle). For your manual transmission I`d use nothing but Amsoil MTG if you need the GL4 75W90 weight. It completely cured the 1st to 2nd gear crunch I was having and has eliminated the bearing rattle. It a fairly new transmission. Factory defect or just simply the wrong transmission oil installed by the Nissan dealer.........I`ll never know for sure but since I installed the MTG both problems have completely vanished.

 

[Jimmy9190]

Interesting. I would hope the Synpower gear oil will hold up better. I used Mopar factory lube last time 30k ago and it's the same 75w-90 and says on the bottle it's synthetic. Trouble is it costs $15 a quart and I have to drive a long way in heavy traffic to the dealer for it. Napa down the street sells Synpower for $11.99 a quart. My transmission has a little crunch going into 1st and when going from 1st to 2nd that I really attribute to normal wear and tear. If I don't release the clutch just right when the truck is cold I get a lot of chatter and wheel hop. I thought Valvoline might do better at helping than Mopar.

 

[01rangerxl]

Yes, very interesting. I guess I should keep an eye on the DuraBlend 80W90 I put in my truck. I was amazed at how good the OEM fluid looked with 57K on it and almost felt like I should have left it in longer (Ford's interval is 125,000 miles). I think next time I will go with a full synthetic like Mobil 1...hopefully next time won't be too soon.

 

[Tones]

Did you see Amsoil's white paper on gear oils. It is eye opening. It can explain why your gear oil turned black.

 

[02zx9r]

i would second the MTG!!

 

[JohnBrowning]

I have used a lot of different dino gear lubes and never had any of them come out any darker then weak tea most looked just like they did when they went in! Prior to makeing the switch to Redline I used Mobil-1 Gear Lube almost exclusively for a long long time more then 10 years at least and it has always come out of a gear box,transfer case or diff looking just like it was brand new. Now until recently I always followed the 24 months or 24,000 mile rule of thumb with gear lubes even if they where synthetic but a few times I went as long as 3 years and about 50,000 miles and again never had any M1 come out that did not look and smell almost like new! So I would stick M1,Amsoil and Redline for synthetic gear lubes or Schaeffers it seems like more and more the performance of allthe other brands is all over the place! Now the Schaeffers is black in the bottle because of it's additive package.