Beware the Dangers of Automatic Transmission Fluid Additivesby KC Martin Transmissions on 08/07/17
Being proactive and doing all you can for your car's health is admirable for sure. But as the old saying goes: if it sounds too good to be true it probably is. That's what we think of when it comes to these advertised transmission fluid additives that claim to stop leaks and correct issues that are becoming apparent with your transmission. These types of additives are a bad idea, and should be avoided---if you want your transmission to work better in the long run, that is.
Do these "fix all" additives work?
The truth is that these automatic 'transmission fix' additives DO have an affect, just not quite what they promise when they're selling it to you. In short, they DO NOT WORK.
Why Would Someone Use An Additive?
Okay, let's talk about your automatic transmission. Eventually, areas of the transmission will fail, just like any other part or machine---and particularly one that is used as often as a transmission is. Your transmission has many clutches and bands, with oil pressure functioning to move hydraulic pistons.
It's a complicated apparatus, your transmission, but in order to work correctly, there are seals that contain the pressures and keep fluids in place. Over time, these rubber seals become rigid or hard and pressure is not contained properly and fluids can leak as well. These additives propose to stop leaks and make your transmission run better, and if you don't know how your transmission works, they SEEM to do just that.
If These Don't Fix The Problem, What DO They Do?
This is the tricky part. The additive will immediately (in a day or so) work to soften and expand these rubber seals chemically. This allows them to expand and stop the pressure and fluid leaks. Your car or truck will run better and work better to you the driver. Then, you move on because "it's FIXED!", right? Wrong!
What happens next is that the seals start to swell and usually do not stop doing so until they are worn away or stretch to the point that they are not effectively holding their shape anymore. If these seals fail, your transmission has a COMPLETE FAILURE, a much more costly issue. The worst part, is this usually happens only months after you use the "transmission fix-all" additive.
What is the "Right Way" To Handle These Problems With The Transmission?
First, know that these seals in your transmission becoming hard and brittle is a normal occurrence. And, although you should have a transmission specialist (like KC Martin Transmissions) check it out, there is no real panic when this begins. When the car is cold, the seals are more brittle, but they soften and work better as the car warms up. So, you have a "grace period" of sorts, to get it checked out and diagnosed by a pro. This is why we recommend getting your transmission checked out as soon as it sticks or delays to engage.
There is no easy way out. The seals must eventually be replaced. And although it's not something anybody wants to pay for, it's much more cost-effective to have it done when the transmission still functions, than to be dealing with a complete transmission failure. Transmission replacement is one of the most expensive car repairs in existence.
The Bottom Line: These fix-it additives are BAD NEWS, and don't actually fix anything.
What Do I Do If I Suspect A Used Car I've Purchased Contains Additive in the Transmission?
Go see your trusted transmission pro and have them check it out ASAP. In fact, it's best to have this done BEFORE you finalize the deal for any used car purchase. Luckily, it's pretty easy for a pro to tell if an additive has been used---for instance, it significantly changes the scent of transmission fluid from something sweet, to more like a sweaty smell (sounds weird, but it's true). At least you can get the problem fixed or avoid purchasing the car if you don't want to deal with the cost of transmission seal replacements.
We hope this information helps you avoid a costly error, and thanks for reading KC Martin Transmissions Official Blog. For almost 70 years (69 years to be exact) KC Martin has been the first name in Transmission Repair for the Lynnwood, Edmonds and South Everett, WA areas. If you're in the area and have any questions about YOUR transmission issues, please feel free to contact us!