So what type and brands are you guys using for Automatic Transmission Fluid? I've used the Valvoline Max Life Multi Vehicle full synthetic in a few vehicles with good results. Would it be ok to use in the C5?

 

I've only bought it once, and that was over 10 years ago. I bought whatever Dexron (3?) was recommended, or newest version (Dexron 4?), for my 4L60E at the time. Changed fluid and filter @100,000 miles It was a good brand name bought at the auto parts stores. It also was NOT synthetic. FWIW, I have almost 150,000 miles on my car now, with a totally stock internals 4L60E, with a Yank 3,200 converter (90,000 miles on the Yank).

 

Dexron VI is backward compatible and full synthetic, but twice the price of the Valvoline multi use. I'm good to pay for it if it's better. Is it?

 

Tranny?

 

Auto - 4L60 E. I'll have ACDelco Dexron VI here in the morning. Thanks everyone.

 

Has the fluid been changed before?
Personally, I wouldn't mix full synthetic with non-synthetic Dex III.
Looking online, many trans builders just recommend Dex III for the 4L60E.

 

Nice looking C5 in your avatar.

Yes, I've changed it a couple of times - most recently about 2,000 miles ago. I did use the Valvoline Max life synthetic fluid, and it's been fine until now. Our Corvette club had a week long cruise this summer from the Seattle area to the Redwoods in California and back, and the car ran amazingly well, running nicely with C6's, C7's and C8's. Last week I noticed a small trans fluid leak after the car had been sitting in our cold garage for a couple of weeks, Not a lot, but a small line of drips on the garage floor after I backed it out. I'm going to get the car nice and warmed up, change out the diff fluid, and do a tranny drain and refill and add a bottle of ATP AT-205. The AT-205 just worked wonders on a rear main oil leak on our 65 Sting Ray. I went from about a 2-3" overnight oil spill on the floor to bone dry in 2 days after adding it to a fresh oil change and about 25 miles of driving. It's still bone dry. I'm hoping it works as well in theC5's transmission.
I believe Dex III has been discontinued and is no longer available. Dex VI is backwards compatible and I believe it is fully synthetic. I was wondering if the synthetic fluid was a bit thinner and more likely to leak - especially after sitting in the cold temperatures. Regardless, Dexron VI synthetic is going back in - with the added seal conditioner. Wish me luck.




Here's about a 45 minute video of the trip.

 

Am I missing something here? You changed the fluid, and assuming the filter, two thousand miles ago, and you think you should change it again???? You must be having some sort of issue, because nobody I've ever heard of changes fluid every 2,000, or even 20,000, miles. If you are having a transmission issue of some sort, 2,000 mile old fluid is NOT the problem.......

 

Says he has a fluid leak, so I'd guess he's dropping the pan for that.

 

Ya gotta read the WHOLE post, he explains why.