General Motors has published multiple technical service bulletins pertaining to torque converter clutch shudder issues in their 8-speed transmissions. This problem currently affects 11 different models across 3 different OEM brands for the model years between 2015 and 2019.
After implementing several fluid revisions, GM’s latest solution (TSB 18-NA-355) is lengthy, complicated and expensive. It requires 20 quarts/19 liters of costly ATF (the average retail, online price for this fluid is $18.10 per quart) be flushed through the system to replace as much fluid as possible, yet, it still has not corrected the issue in all cases.
We at LUBEGARD have been receiving TCC shudder/shifting issue related calls on the 6- and 8-speed units for years. Because the 6- and 8-speed units were based on the same design and engineering, it was not a surprise that they have remarkably similar problems such as slippage, shudder, jerking, harsh engagement, delay in downshifts/ acceleration and component wear.
There are plenty of programing, mechanical and wear problems that can cause the same unwanted shudder or surging; however, the biggest source of the problem was and continues to be the result of additive depleted ATF. OEMs complicated it by calling the fluid “fill for life,” another bit of questionable advice to owners who are unaware that their driving habits, not the mileage, would determine service frequency,.
In May 2022 GM finally concluded that the transmission fluids they have used and relied on for extended warranties for the last 30 years have a major problem. It is a problem we at LUBEGARD have been aware of since our founding and has been the focus of our research and development as a company that specializes in tribology. It is ironic to us that the problem was finally recognized by the OEM and called by the name we originally gave it over 30 years ago: “additive depletion.” In their recent TSB (#20-NA-142) published in May 2022, which is titled “Complaint: “Shudder/surging while driving”, additive depletion is called out as the culprit. It is certainly not a new problem, but the acknowledgment of the actual cause of the problem is a first for GM. Per the TSB: “this condition may be caused by additives in the transmission fluid that may have been depleted during vehicle operation–some of these additives assisted with regulating a consistent slip rate of the clutches.”
TCC shudder and “fill-for-life fluids” are certainly not strictly a GM issue. As you may have noticed, automatic transmissions as well as CVT and DCT units have frictional durability and other performance problems caused by additive depletion in fluids. Fill-For-Life fluid, or extended fluid change intervals, have added to this problem. There is no such thing as a fill-for-life fluid. Fluid breaks down over time. This is a fact. There are many factors contributing to the fluid breakdown, i.e., driving conditions, temperature, driving habits, etc. There isn’t a “magic bottle” that will bring a worn-out fluid back from the dead; however, there are ways to extend the life of the fluid and prevent premature fluid breakdown by restoring the additive content such as friction modifiers, defoamer, anti-wear additives etc. that are vital to the performance and functionality of transmissions.
Since 1984 LUBEGARD has been developing solutions for additive depletion issues in ATF. LUBEGARD PLATINUM ATF Protectant came into existence as LUBEGARD’s premium formula designed specifically for extending the life of transmission fluid by improving oxidative stability, reducing component wear and preventing low-speed frictional problems like TCC shudder. LUBEGARD also restores depleted anti-wear additives and friction modifiers to an additive consumed/inadequate ATF.
Using our state-of-the-art Falex Multi-specimen testing platform, we replicated the conditions that caused shudder to occur between GM friction and steel plates that were lubricated with GM’s recommended ATF. We then ran the same test with the addition of LUBEGARD PLATINUM ATF Protectant and were able to not only eliminate the shudder but were also able to reduce slippage when the treat rate was doubled from 1 ounce of PLATINUM per quart of ATF (our normal treat rate) to 2 ounces per quart.
LUBEGARD PLATINUM formulated with Synergol TMS, which is a proprietary anti-wear and friction modifier improves the performance of any new and used ATF by preventing shudder, reducing friction, improving cold and high temperature performance due to the ester content. A third-party test also reveals that LUBEGARD PLATINUM ATF Protectant shortens shifting variant by 50% compared to an untreated ATF, providing tighter and quicker shifts.
With many of these vehicles with 8-speed transmissions having reached or approaching the end of their limited powertrain warranties, you can expect to see an increase of these vehicles in your shop. The 6-speed is still available in 2022 models, so you can expect to see them far into the future. This is a problem that isn’t going away, but LUBEGARD can offer a less complicated, and more economical service solution. If your customer is suffering from TCC shudder/surging and/or slippage, or signs of wear due to fluid degradation, you can help them avoid expensive fluid change by simply adding 2 bottle (20 ounces) of LUBEGARD PLATINUM ATF Protectant. Two 10-oz bottles of LUBEGARD PLATINUM are $40 vs. 20 quarts of OEM recommended fluid solution at an average retail price of $18.10 per quart. That’s $362, not including labor!
If your customer decides to go with the total fluid replacement recommended by GM, you can still add LUBEGARD PLATINUM to the new fluid at same treat rate of 2 fluid ounces per quart of ATF to avoid reoccurrence of TCC shudder.
For more information, visit our website at www.Lubegard.com