JetstreamGS

Wanting to change out my trans fluid. Cold shifting can be a bit too rough and notchy for my liking. What are you folks running? D4? Torque Drive? What's the best fluid for these 6060's? I want it to shift smooth and effortlessly lol. Thanks folks.

NY09C6

I went with Redline. Did not notice any real difference. I think for many it is a placebo effect.

JetstreamGS

Well that's not what I wanted to hear haha. I was hoping it would improve shift quality. Perhaps I need to invest in a mgw shifter.

hubes

I changed to amsoil torque drive and it got worse. So I drained it and filled it with royal purple synchromax and I think it's now a little better than with the stock fluid

JetstreamGS

I think I may just replace it with fresh oem fluid. Nothing like overspending on a product that may cause more harm.

pickleseimer

I used the stock fluid (88861800) in the C6. Was not having any shifting issues but replaced it to see what the OEM fill was looking like after about 5k miles. 7k miles now on the 427 vert, and the shifting is butter smooth, smoother than either my C5 or C7 with more miles on both of those cars. I've tried numerous brands (Royal Purple, Amsoil, Mobil1) in my C5 and haven't noticed anything significantly different, and the cold weather performance was the same. I called Tremec a few years back and they recommended Mobil1 Synthetic ATF. Other than the boutique brands it isn't hard to imagine it may all be the same stuff. The GM fluid is reasonably priced with some good deals occasionally on Amazon. In the end I realized I was overthinking it.

sccaGT1racer

I had a cold 2nd gear grind with the stock fluid. I changed to mobil 1 syn. The issue is gone.

jayyyw

I had a cold 2nd gear grind. Went to Pennzoil Synchromesh and it went away. It also shifts better the hotter you get the fluid.

Ahrmike

Redline user here.

If youre getting 2nd gear grind:

1) Change clutch fluid reservoir (use the ranger method)
2) Allow the trans to heat up before shifting at higher RPM (or skip 2nd fully until you get it warmed)

NY09C6

#2 was how I handled this when it was below 30F in the NE. It only took a few miles to warm it up.