2009 Tacoma Rear Diff UOA Redline 75w90 27,890 mi

[86cutlass307]

First sample for this Tacoma 2WD rear differential. Please comment as I need to understand better the lab's Phosphorus comment and Redline gear oil. Factory fill was changed at 11,376 miles. Total miles at sample time was 39,266. Flagged data was the phosphorus level. Viscosity seemed in line with Redline's data.

Lab comment - "Flagged data does not indicate an immediate need for maintenance action. Continue to observe the trend and monitor equipment and fluid conditions. Phosphorus is slightly high for this lubricant. Lubricant change acknowledged."

WEAR METALS (ppm)
Iron - 41
Chromium - 0
Nickel - 0
Aluminum - 0
Copper - 0
Lead - 0
Tin - 0
Cadmium - 0
Silver - 0
Vanadium - 0

CONTAMINANT METALS (ppm)
Silicon - 14
Sodium - 8
Potassiium - 0

MULTI-SOURCE METALS (ppm)
Titanium - 0
Moly - 1
Antimony - 0
Manganese - 0
Lithium - 0
Boron - 378

ADDITIVE METALS (ppm)
Magnesium - 0
Calcium - 15
Barium - 0
Phosphorus - 3002
Zinc - 11

Water - < .1 - Hotplate
Viscosity @ 100 C - 16.5
Acid Number - .60 mg KOH/g

 

[jegs]

Phosphorus is part of the additive package in the oil. Since Redline is geared towards racing I'm not surprised it's slightly higher than other gear oil. Nothing to worry about. The wear metals look good. Your diff should live a long and happy life.

 

[dnewton3]

I hope to goodness you didn't OCI with this UOA, did you?

Generally, once you flush out the FF, gear lubes can stay in a long time; especially syn choices.


Overall it looks fine.

 

[86cutlass307]

I took the sample through the fill port using the trusty siphon tube; Redline is like gold. Anyway, lube still had its amber hue at this sampling so I was hoping to let it ride. I have had several long highway trips over the last couple of years and was curious how the gearset is beginning to age. Overall I'm pretty happy with the lab results. I'll say the silicon was due to the windy/dusty day in North Texas on sample day for my peace of mind. This differential and my driving habits seem to be a good match with this Redline lube. As said above, should live a long and happy life.

 

[INDYMAC]

Thanks for posting. This is the first RL 75W-90 UOA that I find inspiring. Did you top off after taking the sample?

 

[86cutlass307]

Yes, I let a few seconds worth drain out before the capture. I had some left over from the change back at 11K and just topped up. I tilted the axle ends to let the fluid level run down the tubes and stopped when the fill hole started a drip/run. Should be good for some time to come, seems stout for a street truck lube.

 

[dnewton3]

41ppm Fe is pretty low for a diff, but then your sample duration is also low, hence your wear/mile is fairly normal.

Great to hear this was a sample and not an OCI.

No reason not to continue this run!

 

[MolaKule]

I wouldn't worry too much about the silicon since RL uses about 8-15 ppm of silicon in their formulations.

The phosphorus is most likley part of the Sulfur-Phosphorus Extreme Presuure additive.

 

[Izb]

What potential harm (for example for oil seals) can be from a high level of phosphorus?