For a while now I have been looking for a way to simplify the DCT Maintenance on my car. I believe I’ve got it down to a science now and I want to share. This procedure takes me less than 2 hours from start to finish, without rushing and without cutting any holes in the shear plate.

Tools You Will Need.

7mm Socket
10mm socket
13mm Socket
15mm Socket
17mm socket
E16 Socket
E8 Socket
Torque Wrench
MityVac Fluid Dispenser (manual or shop air)
Foxwell NT710 or similar scanner that can run the hydraulic flush procedure.
QuickJack, lift, wheel cribs, something to get the car up high enough to work under it and keep the car level.

Then of course DCT fluid and External filter.
Rock Auto has a great price on both, you will be into this for under $450 in materials for the filter and 12qts fluid.

1. Drive car up to operating temp, park, and run hydraulic flush procedure.

2. Lift Car.

3 Remove shear plate, this takes less than 5 mins with a cordless impact. I see no reason to cut a hole in it. Note: I recommend replacing the E16 bolts with normal flange head bolts.

4. Remove trans fill plug with 17mm wrench or socket.

5. Place drain pan under trans.

6. Remove trans drain plug with 13mm wrench or socket and allow to fully drain then reinstall drain plug and torque to 18ft/lbs.

7. Remove 4 bolts from external filter with E8 socket, grab the casted fins on the cover with a duckbill pliers and rotate while pulling. It comes off hard because there is a o-ring. At this point fluid will drain but you still need to pull the filter cartridge. You can grab it with a needle nose and pull it out. Allow to fully drain.

8. Install new cartridge filter, you have to push hard to seat it.

9. Install cover with new o-ring and fresh bolts that are included with it. You will once again have to push hard to seat the cover because of the o-ring. In stall bolts and snug them up. I know there is a torque spec for this but I just snug them with light pressure as they are very small.

10. I use a 10qt shop air MityVac, they are like $300 on Amazon. So I fill the unit with 10qts of fluid, connect to shop air, and pump the fluid into the fill hole on the side of the trans until it drips. This takes about 5 mins and I get about 8.5qts in it initially.

11. Replace fill plug and snug it up.

12. Start car, while holding the brake repeatedly shift it from D-N-R and R-N-D holding it in each gear for about 5 seconds. I do this for about 10 cycles. Shut car off.

13. Remove fill plug and continue to pump fluid into the transmission. I end up getting a total of 9.5qts in there before it starts to drip.

14. Reinstall fill plug with new gasket and torque to 18ft/lbs with 17mm socket.

15. Reinstall shear plate, torque E16’s to 21ft/lbs. I just snug up the 7’s, 10’s, snd 13’s.

This concludes the service. Do not be intimidated by it, it’s simple if you have the tools.

I add the extra 2qts for track use, this is simple as well.

1. I place a quick jack under just the drivers side and lift the car as high as I feel is safe.

2. Remove drivers side rear wheel.

3. Remove trans fill plug.

4. Dump 2qts DCT fluid into mityvac and pump into the trans.

5. Replace plug and torque to spec.

6. Install wheel and lower car.

There is no reason at all to take the trunk apart and pull the air box for this.

I know I didn’t take any pictures but hopefully this helps some of you that have been considering doing it yourself and not getting graped by the dealer.

 

Looks good. The version for the filter replacement procedure I have includes a call to the Hydraulic System Leak Test. Are you skipping that?

Its not clear what that procedure does - when folk report running it it seem to conclude without issue. Presumably its looking for something internal because there are no instructions to look for external leaks. And, speculation, if it does find an issue, something will appear on the scan tool about what to do next. But no one has ever reported that happening.

 

There are no second hand scan tools at the moment that will perform the leak test. I know some of them like Foxwell have it under development. You would need a MDI2 or a clone to do it.

I just skip it, my thoughts are if you didn’t have any issues before the fluid change you are not going to have them now. Additionally, no one I’ve spoke too can even explain what actually does or what it’s looking for.

 

Depends on the model year of the car. There are several scan tools that can do the DCT service routines on 2023-later C8 Stingray and ERay. 2022 and earlier Stingray's and all Z06/ZR1 require MDI-2.

DCT Service, Fluid Flush, Leak Test, etc - Works A-OK with X431 GM Scan Tool

 

So I know the NT710 will run the flush on 2020 to current model years but will not currently run the leak test. Are you saying the x431 will run the leak test on 23+? This is confirmed?

 

Great write-up. I just did mine a week or so ago for this seasons track season. I did everything except the HSF. I'm on my third DCT filter. The second one which I cut open didn't have a significant amount of debris. This will be at least a once a year process for me.

 

For 2 hours of my time I'd rather take it to the dealer.

 

Why 12 quarts?

 

Can get up to 9.5 liters out on a long drain. Plus 2 more for track fill. 12 is insurance....

 

Most dealers are charging in the neigborhood of $1500 to do a drain, fill, and filter change.

Considering the parts are less than $450 I am more than willing to sacrifice two hours of my time to save over a grand.

 

Annual for me as well.

 

Yes, I've personally done all three on the x431 tool.

 

Great Info! Thank You.

 

I paid less than $700 for the DCT fluid change and service. Not worth the trouble to do it myself.

 

This plus I don't trust other peoples work. The dealer will probably put the FNG on a simple high profit job like this...

 

That’s and exceptional price considering they sell the fluid for $50 a quart and charge over $200 for the filter.

You have a great dealer, however, I still wouldn’t trust them. A lot of dealer techs are very skilled, but most also don’t give a **** if it’s a 2005 Malibu or a 2025 Z06. They impact everything and just worry about getting it out the door as fast as possible just betting on it not coming back. The joys of flat rate mechanics.

 

Absolutely Agree Breecher.

Jobber price on the #24045729 DCT filters is $78.00 each + $6.75/qt (10 qts) for Valvoline FFL-4 DCT fluid = it costs me $145.00 + 2 hours of easy work.

- No complimentary grease smudges on the leather/headliner/carpets
- No complimentary belt buckle scratches or door sill scrapes
- My ERay misses the opportunity to sit outside for three days underneath Pigeons with bowel issues
- My ERay misses a "test drive" opportunity from a 22-year old named Bryce

In my shop EVERYTHING is done and done properly with attention to detail. $700 is not happening around here, but using that number is paying myself $275/hr to avoid the above "dealer services" = PRICELESS.

 

I've been on the fence on using the Valvoline Fluid, what's your opinion on it? Any noticeable difference in shifting or material in the filter?

 

I don't trust dealers period. Prior to Covid, I would occasionally take a vehicle in for "dealer service". Covid showed me how pervasive greed and dishonesty are at most car dealerships. There are a couple of small local service shops that do great work that I use on occasion, but as of the past few years, dealers are warranty work ONLY.

A GM dealer in this area was caught scamming oil changes. People were paying for synthetic oil changes on their Cadillac's, Corvette's, Denali's etc......and the dealer was installing el-cheapo no-name bulk motor oil. This type of fraud is rampant because more than half of a dealers yearly profit comes from parts/service.

Think about it.....if a dealer will scam a $150 oil change, what about a $1,500 DCT service? I have seen several C8 DCT's drained of oil....all were clear and clean as honey = no easy way to tell if it's been done....too tempting for fraud = HARD PASS.

Typical New Car Dealer Gross Profit:

• New Cars: 7-10%
• Used Cars: 12-15%
• Service & Parts: 45-55%

https://www.krusecontrolinc.com/top-...-gross-profit/

 

Like OEM.....no difference at all with shifting and operation. Nothing unusual in the filter. I only started using it after several guys that run their C8's @ Road America vouched for it. Valvoline is a tier-1 GM racing sponsor, I would expect nothing less than oem level function.