Piston Slap: Dreading "The Dreaded" ATF Flush?

Sajeev Mehta
by Sajeev Mehta

Jackson writes:

I own a 2001 Nissan Maxima and a 2006 Corvette, both purchased new w/cash. I know the Maxima with 105,000+ miles has had two ATF services, which included the “dreaded ATF Flush”. So far the thing keeps running, only issue (unrelated) was a Cat replacement (99,000) and 3 O2 sensors around the same time.

The 2006 Corvette at 5 years and 42,600 miles is due for a coolant service and I see that the ATF service is 50,000 (harsh) or 100,000 (normal). So far expenses have been limited to gas, once a year oil changes and a set of tires at 26,000 due to some aggressive driving, aggressive factory camber settings and a shard of metal. It’s been spotless so far besides a squeaky roof panel which has been solved by periodic application of Super Lube to some contact points. Should I do an ATF flush for the vette? It would be a BG machine. It’s a warm weather commuter for me (42 miles round trip per day of which 26 is highway miles on which avg. speed 75 mph which is just 3 days a week).

I have taken it on 6 long trips over the years as well as weekend cruises. I do use the paddles about 30% of the time, but do not really hoon it so much the past 2 years after getting 3 speeding tickets in 6 month period…which I fought and is another subject. So please advise.

Sajeev answers:

The easier of the two to E-diagnose is the ‘vette. First, I really hope you ditch(ed) those run flat tires for some donuts befitting a Porsche 911, as that is what the Corvette deserved from the factory. And like much like Motor Trend’s game changing car of the year, the 1997 Chevy Malibu, the C6 Corvette comes with a sealed-for-life transmission. Which begs the question, where did you hear about a 50,000 mile service interval under any condition? Not that owner’s manuals are always right, but I seriously doubt you read that from your glovebox.

These gearboxes normally go 100,000-ish miles before servicing, and your driving habits are definitely within that realm. If you have the motivation, check the fluid’s condition using the link’s info. Odds are the ATF is fine, it should have a pink color with a slightly sweet smell. If it has black-ish bits and smells like a BBQ pit, change it according to factory procedures…and good luck with that!

Now about the Maxima: I question if an “ATF flush” is really something to dread. I’d be quite thrilled with your vehicle, if I were to buy it from you. The biggest plus in the flush’s favor is how it blows out all the old fluid from the torque convertor, which is essentially impossible in vehicles without a drain plug on said convertor’s case. While it doesn’t change the transmission filter, I’ve been told by several techs that this filter isn’t exactly that high tolerance in its filtering capability. Which implies…

…that doing the “dreaded ATF flush” when your fluid degrades essentially makes the transmission filter a lifetime service part. My thoughts are completely debunked over here, but I see their opinion as more applicable to car with more advanced transmission failures.

What say you, Best and Brightest?

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry.

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2 of 17 comments
  • Cardeveloper Cardeveloper on Aug 03, 2011

    Trans flushes can dislodge material that can cause other issues. Just drop the pan and change the oil. If it's really bad, do it again in 1-2k miles.

  • CougarXR7 CougarXR7 on Oct 26, 2011

    I've never liked machine flushes due to the fact that they completely ignore the gunk trapped in the filter and the bottom of the pan. I plan on flushing and filling my 101,000 mile '95 Lexus LS400's tranny 3 or 4 consecutive times with Mobil 1 ATF.

  • Jeff S Still a nice car and I remember these very well especially in this shade of green. The headlights were vacuum controlled. I always liked the 67 thru 72 LTDs after that I found them bloated. Had a friend in college with a 2 door 71 LTD which I drove a couple of times it was a nice car.
  • John H Last week after 83 days, dealership said mine needs new engine now. They found metal in oil. Potential 8 to 9 month wait.
  • Dukeisduke An aunt and uncle of mine traded their '70 T-Bird (Beakbird) for a brand-new dark metallic green '75 LTD two-door, fully loaded. My uncle hated seat belts, so the first time I saw the car (it was so new that the '75 models had just landed at the dealerships) he proudly showed me how he'd pulled the front seat belts all the way out of their retractors, and cut the webbing with a razor blade(!).Just a year later, they traded it in for a new '76 Cadillac Coupe de Ville (they had owned a couple of Imperials in the '60s), and I imagine the Cadillac dealer took a chunk out to the trade-in, to get the front seat belts replaced.
  • CaddyDaddy Lease fodder that in 6 years will be on the 3rd owner in a poverty bound aspirational individual's backyard in a sub par neighborhood sinking into the dirt. The lending bank will not even want to repossess and take possession of this boat anchor of a toxic waste dump. This proves that EVs are not even close to being ready for prime time (let's not even talk about electrical infrastructure). EVs only exist in wildly expensive virtue signaling status-mobiles. FAIL! I know this is a Hybrid, but it's a Merc., so it will quickly die after the warranty. Show me a practical EV for the masses and I'll listen. At this time, Hybrids are about the way to go for most needing basic transportation.
  • Jeanbaptiste The bubble free dash on the R32!