For those that have made the change to Valvoline DCT, did you just drain, fill and go? I realize it would be prudent to fill with the Valvoline DCT fluid, run the new fluid through the trans and drain/fill a second time. Is it the forum consensus that a second drain/fill is not necessary?

 

Yes we don't need to drain and refill new Valvoline DCT fluid twice to convert, Valvoline blends with the OEM DCT fluid.

These days GM does recommends doing a hydraulic system flush when changing fluid, not just during a filter change. This was created by GM through Tremec to help catch and dislarge contamination found in DCT solenoids.

I would also changing your DCT filter to a new OEM that can be purchased from RockAuto at half the dealer price.

Do the HSF PRIOR to adding the new Valvoline fluid and new OEM filter.

Congrats and great move changing over to a better DCT fluid than what comes with the C8. Valvoline DCT fluid and is 100% synthetic, The OEM fluid is a mystery synthetic blend, as in nobody knows what this blend is and each bottle must be wtf shaken.

Been running Valvoline fluid for well over 2 years and have added additional HP/TQ through tuning and many Mods in my almost 6 year journey.

 

From the following, the flush is done after filling with new fluid (step 11).

https://www.corvetteforum.com/forums...162d1769003908

 

It still makes sense to me to run the HSF before the filter change.

 

This is what I am not comprehending. I would agree doing it this way makes sense.

Since the fluid I used needed to be shaken, not stirred, I wonder how much risk I have by not physically shaking mine. I did use it very quickly from the time it was delivered. I hope that it got shaken during the ride from RA to my shop. As I poured the left over fluid into he next container I did not notice any separation of the fluid. It appeared to be all the same color. One thing I did notice is that there is a little bit of red color in there.

I have an 84 month GM Platinum protection plan. I wish I could get a solid OK to use the Valvoline.

 

I think it would be a big help if all of these DCT threads were put under one sticky. Who could I ask about that?

 

What was the cost of the Valvoline DCT fluid in comparison to the AC Delco DCT fluid?

 

I have yet to hear of a single failed DCT running Valvoline. Not saying is better than OEM fluid, but it sure does not seem to cause any issues.

 

The risk reward for saving a few bucks on DCT fluid doesn’t trade for me. The cost of a warranty denial is too great. Especially if one does the fluid change yourself. I’d consider the change after the GMPP is no longer in place. I change the fluid yearly due to track time.

 

About one third the cost.
Fuchs is about half the cost but is the fluid recommeded by Tremec themselves.

 

Why is it the dct in my 21 Mercedes GLA35 AMG has no maintenance required until 60,000 miles and no time limit. They are both performance oriented 8 speeds and similar designs. The main difference is Tremec and ZF.
Just found out, the GLA trans is made by Mercedes AMG not ZF.

 

Are they really similar? Clutches and differential share the same fluid? I think that's a big factor in maintenance and issues experienced by the C8

 

Shared transmission fluid for clutches, gears, and actuation system.

 

True in the C8. How many other DCTs have shared fluid like the C8? I'm under the impression that the C8 is a bit unique with common fluid for clutch and other circuits.

 

most DCT trans use shared fluid.

 

As noted, most DCT transmissions have shared fluid. I think the reason most (all?) other longitudinal DCT transaxles have separate fluids is because hypoid ring and pinion gears need a hypoid oil to address the high pressure sliding contact. The TR9080 uses spiral cut ring and pinion gears with little sliding contact, more like helical gears so they can get away with a non-hypoid fluid for the whole transaxle.

 

I've been running valvoline DCT fluid since my VB failure and no issues. I did two changes mainly to get all the debris out from oem fluid as a few residual quarts will remain. You don't have to do it but I did for peace of mind since the fluid is so cheap. I will say on second change there was still a little debris noted in the fluid so I'm glad I did it.

 

Yes, I have seen your images of debris in the fluid. Its a real thing. As I recall from other threads, you have a modified C8, and you drive it hard regularly. Nothing wrong with that at all. But it shows why the manual calls for a fluid and filter change every 24 hours of track use (which is going to be 2400 miles or less). And that is, the transmission sheds more, maybe much more debris when driven hard and it really does not matter if its actually on the the track or on the street. So if someone is driving very aggressively on the street, and/or doing frequent launch events, stressing the transmission and particularly the clutches, then more frequent filter and fluid changes should be considered.

You have to wonder too how long the clutches will last if that much visible debris (from your images in other threads) is being shed with track-like driving. They are purported to be lifetime components (which might be "100K" miles) for normal use. But you really can't hide the fact that there is more debris shed during hard use, confirmed by both your images, and the frequent fluid and filter change requirement in the manual for track use.

I wonder if the fluid matters with respect to clutch debris shedding. I recently took a look at the Safety Data Sheet for Valvoline and ACDelco DCTF FFL-4. From that it would appear that Valvoline is made entirely from highly refined crude oil known as Group III oils, which can legally be called full synthetic. The Delco product is a blend of highly refined Group III oils and a substantial amount of lab engineered Polyolefins - also legally a full synthetic it would appear. Redline DCTF is actually lab engineered containing Esters (Group V) and Polyolefins (Group IV) oils. I wonder if use of the Redline product would make a difference in how much debris you are finding in the fluid. I'm not sure at all that it would. A big part of any of these products is the friction modifiers that are necessary for wet clutch function. It may very well be (and I am guessing here, no particular knowledge) that the additive package affects the way the clutches wear more than the exact oil formulation.

 

great questions and agree on the usage statement. I’m changing fluid regularly now. I was not aware of those specifics on valvoline vs redline vs delco. The fluid analysis does show insolubles as the debris so in theory could keep track w different fluids w similar use the insoluable amount and maybe track this.

 

In all of this, the big, BIG question is: why isn't the filter trapping this debris?