What did the RP look like coming out of a NV5600?

[JOblenes]

I just changed the fluid in my trans (NV5600). I had put Royal Purple Suncrhomax in the truck when I did my PTO at about 6800 km. I am at 29,000 km now. The fluid that came out looked something like the colour of burnt ATF. I had (have) no idea what to expect given the heavy purple color of the original fluid. Is this normal? Also, I hadn't really noticed the shifting getting bad over time, but it has definitely improved with a fresh dose of synchromax.

 

[Gary - K7GLD]

I just changed the fluid in my trans (NV5600). I had put Royal Purple Suncrhomax in the truck when I did my PTO at about 6800 km. I am at 29,000 km now. The fluid that came out looked something like the colour of burnt ATF. I had (have) no idea what to expect given the heavy purple color of the original fluid. Is this normal? Also, I hadn't really noticed the shifting getting bad over time, but it has definitely improved with a fresh dose of synchromax.

Can't say about the RP - or the added effects of the PTO - but I ran 20,000 miles on the stock DC lube in my transmission, and when I drained and refilled, the old stuff was still as clear and pristine as new - and most of those miles were trailer towing miles...

 

[JOblenes]

I spoke with a representative at RP this morning and recounted my experience. Their response was that the purple color is just a dye (non-UV protected dye to be precise) and that I should not worry about the color change. They said if you leave RP in the sun it will turn brown naturally (not that I'm letting any sun into my transmission). They also surmised that perhaps the high solvency of the synthetic had "cleaned up" some of the old stuff in the transmission hence the dark brown appearance. I am sketptical of this last bit because as I said in the original post there was only 6K+ on it when I switched and, like Gary, the original fluid that came out was in "pristine" shape. Hopefully someone who has been running RP for a while will chime in. As for the PTO, I don't think this will have much impact. I run it once a week for a few minutes just to circulate the hydraulic fluid but have not been stuck enough to need to winch. It also only draws a few horsepower i. e. pump runs 3. 5 GPM @1500 psi (max line load) with the engine at idle 750 rpm and the gear ratio in the PTO producing about 1000 rpm on the pump.