4 Ways to Prevent Transmission Overheating & Avoid Failure

Heat is the number one cause of premature transmission failure. Not manufacturer errors, or even defective parts. It accounts for approximately 90% of all automatic transmission failures.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

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In This Guide

Excessive transmission heat is responsible for the start of many transmission problems including; ruptured seals, cracked gears, slipping transmission bands, failed bearings, inoperable solenoids, and delayed clutch engagement. You name the part, and too much heat can cause it to break.

This silent killer has claimed the service life of countless transmissions, and it could be wreaking havoc on your vehicle every time you put it in gear. An overheated transmission can often go unnoticed until it’s too late and something breaks.

The most common causes of overheating include solenoid problems, fluid leaks, low fluid levels and burnt/old fluid. Other heat generating factors are if you live in a hot climate, often drive in stop and go traffic and/or tow heavy loads with your vehicle.

How Automatic Transmission Fluid Cools a Transmission

It contains chemical additives that provide lubrication and the pressure to change gears, but its primary function is heat removal. The spinning gears, expanding springs, and whirring turbines generate friction as they move about.

This friction produces a lot of heat, which can cause stress fractures, varnishing and other forms of damage to the internal components if it isn’t dealt with quickly.

For this reason, it is formulated to absorb the heat as it flows through the moving parts. It then carries the heat out of the transmission to the radiator, where the hot fluid is forced through a special cooling chamber that uses aluminum fins to extract heat from the ATF.

As air flows through the radiator, the heat is dissipated and the cooled fluid is then piped back to the transmission for another round. If it isn’t able to remove and expel heat through the factory transmission cooler fast enough, the transmission will overheat and damage will start to set in.

Fluid Life Expectancy vs Temperature

Over time, heat breaks down the organic compounds inside the fluid, causing it to take on a darker red, then brown, then black color. It also becomes thinner, which significantly reduces the amount of heat that it’s able to carry away from the moving parts.

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If your transmission isn’t serviced (new fluid + filter) every 20,000 to 30,000 miles or once every 12-18 months, the fluid will become ineffective, and the normal operating temperature will increase.

The ideal operating temperature of transmission fluid is 175 degrees. Overheating occurs after the temperature surpasses 200 degrees, and the failure rate doubles for every additional 20 degree increase after that.

So if you drive the vehicle with the fluid temperature at 240 degrees, your transmission will develop significant problems and fail 4 times sooner that it would have otherwise. Fresh, clean fluid on the other hand, will make it run cooler, shift better, and last longer.

Fluid Temperature & Damage

  • 220-degrees = varnish forms on metal surfaces
  • 240-degrees = seals harden
  • 260-degrees = transmission bands and clutches begin to slip
  • 295 degrees = seals and clutches burn – call a tow truck

For every 20 degree reduction in fluid temperature, your transmission’s lifespan will approximately double!

Low fluid levels will also cause the transmission to overheat, rather quickly. Without enough ATF to remove the heat, the temperature can skyrocket past 260-degrees, resulting in a slipping transmission, along with serious damage to the clutches, bands, and torque converter.

To keep this from happening, check your transmission fluid level once a month, or every two weeks if you spend a lot of time on the road. And don’t forget to leave the motor running when you check it, otherwise you won’t get an accurate reading.

How to Prevent Transmission Overheating

1) Check Transmission Fluid Often

You should check your vehicle’s fluid at least once a month in order to spot issues such as a low fluid level or worn out dirty/burnt fluid. This will allow you to fix these early warning signs before they cause serious transmission problems that can damage or destroy your transmission.

In addition to checking the level and quality of fluid using the dipstick, be sure to look under your car occasionally for stains on the driveway or transmission pan to make sure that your fluid isn’t leaking.

2) Change the Fluid on Schedule

Your vehicle’s transmission fluid should be changed every 30,000 to 60,000 miles. You can change it yourself or have a transmission shop flush it from your vehicle.

If you drive in a hot climate, a lot of stop and go traffic or haul heavy loads, the fluid should be changed more often than the suggested range – every 15,000 to 20,000 miles for example. That way your transmission is always running on fresh, effective fluid that will keep it cool.

3) Add an External Cooling System

Your vehicle’s radiator is responsible for cooling down the fluid, so be sure to change the coolant inside it every 2 years or so.

If you haul or tow heavy loads, the radiator alone may not be enough to keep it cool and you should consider installing an external transmission cooler. A stacked plate cooler for example is easy to install and attaches to the front of the radiator.

4) Add a Deep Pan

If your transmission has overheated, then it is worth considering adding a deep pan. A deep pan allows you to add more fluid to your vehicle, which helps spread out the heat and remove it from the transmission faster. Aluminum pans dissipate heat better than those made of steel.

When to Install a Transmission Cooler

Towing causes a serious amount of strain/heat buildup. So does the constant up-down shifting the occurs when you’re crawling through traffic, or driving in hilly/mountainous terrain.

If you regularly do this type of driving, then you need to seriously consider having an aftermarket transmission cooler installed. Most are designed to work in tandem with the manufacturer’s original transmission cooler, and they provide increased fluid capacity so that more heat will be removed, faster. To keep your transmission temperature from exceeding safe levels, this is the best way to go.

Other Transmission Heat Sources

Worn transmission bands, clutches, and solenoids can also cause your transmission to overheat. If the part isn’t functioning correctly, it can generate excess friction heat and overwhelm the fluid.

Even though just one part is worn or broken, the high temperature can do things like warp the valve body, and destroy the torque converter internals. So if you can help it, try not to drive the vehicle until the transmission is repaired.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

What to Read Next

Over to You

We’re interested to know – has your transmission overheated? If so, how did you fix it? Let us know by leaving a comment below!

21 Comments
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Michael Girardi
13 days ago

2009 ford escape the 6 speed worst tranny they ever made. Some crack in time the aluminum casing is junk. The first one done a crack. Tranny number 2 junkyard 1500 with a warranty to take out put back in pressure problems. Transmission repair shop and ford could not fix it. They said it was good with a 200 dollar reprogram. But pull out dipstick tube and and covered in tranny fluid from pressure. Number 3 was ok for a while then first gear is a jerk now I’m putting in two giant external trans coolers in parallel and do away with the condenser cooler. Ford computer codes never work on a transmission they show nothing. If this dont work and all new lv tranny fluid I’m junking it.

Nick
3 months ago

Bought a 2004 f150. Previous owner put in a new trans (its purple!). Now when i tow my 5k travel trailer i have seen 204 degrees. Oddly enough, this was on flat freeway. No one can pin point why. So it hasn’t been fixed.

Dave
3 months ago

just had transmission rebuilt completely 2 months ago in 1996 Chevrolet 1500, 305 engine. Transmission suddenly went out again 100 miles from home. Back in shop. Shops says transmission overheated. Engine temp gauge never indicated any overheating. Fluid levels always perfect & checked often. I drive very reasonably. What could have happened & what could I have done to cause it.

June
4 months ago

I have a Toyota Avalon and when I drive it it’s fine till I put it in reverse it goes back with a hasitation I did change the fluids and filter when I start it in the morning it goes in reverse fine but when I drive for a bit I use reverse it just hesitates can someone give me some advice

Jerry
6 months ago

On older transmissions the transmission fluid was ran through the radiator. Is this still done one newer vehicles. What about using a smaller radiator with a fan attached or even an larger tank similar to what is used on equipment

Shane
8 months ago

Ok. I must be blind or something. I’m at 56 below at my cabin. -56. My transmission temperature now is at 39 degrees. It says for every 20 degrees lower it will double the life of the transmission. Guess tranny is good for life

CeeBee Taylor
11 months ago

I just bought a 2003 325i automatic 4 door sedan I drove home and that was the end of her the car was start but would only drive in Reverse when put in drive it would just rev and wouldn’t go nowhere so I changed the transmission filter and change the fluid what you did nothing so my next step is it going to OB D2 scanner and checked all the codes and apparently it’s the shift solenoids and the pressure valve in the valve body so check your solenoids and you’re well buddy they have a upgraded pressure valve hope this information helps somebody was similar problems

Debbie
1 year ago

Well it’s gonna be an interesting next few days as I attempt to diagnose the damage to my C6 Tranny in my 96 Rexhall Aerbus. Someone cut the brake and and tranny line. What a mess. I wasn’t sure how much tranny fluid this was to take. I thought I had looked it up as this has never had the tranny serviced. It has 30k miles on it. The auto parts store is a bit confusing because even with them having access to other people and the internet I find that they know less about trannies than I do. First I’m checking for a plugged filter. Which is s huge possibility. We never lost reverse or first. It runs great in reverse. Will let ya all know what I find.
Debbie

Bd
1 year ago

Hi my Allison 2200hs get hot since i went last week on highway.

Mechanic found brass and aluminum inside oil . He want replace whole transmission.

Whats cause this heat up problem as this problem suddenly came over?

Oil level is good. Oil is in good shape. Cooler return line has ample flow.

Any suggestions wellcome

Eddie S.
1 year ago

owner of a 1999 sierra 1500. go up to about 55mph and the rpm jump up to about 2200. feels like it struggling hard. i just got the trans. rebuilt about 3 mnths ago. man and i dont want to spend that amount again. Anyone have a clue?

Bd
1 year ago
Reply to  Eddie S.

How did you fix this problem?

Hunter V
5 months ago
Reply to  Bd

I’ll give you my opinion which may help others . I had a situation like this in my ram 3500 2006 diesel.
I rebuild the tranny in a local shop that they use heavy duty parts better then the original and they strongly recommend me to ad 2 more external radiators plus a deep oil pan which I did it now the temperature is oscillating the 140 degrees with heavy loads and hot weather about 94 degrees every day . Until today no more problems. If you want to keep your ride for long time try my advice. Remember more cooling more life for any automatic tranny.

Bob Eberenz
1 year ago

Have a ‘08 Silverado. Transmission temperature is usually around 150 to 175 when I’m on the highway. Goes up quick if I’m stuck in traffic or idling 200 to 210 or so. When I check fluid it looks ok but it seems like it might be overfilled. Could this be causing temperature to go up ?

Hunter V
5 months ago
Reply to  Bob Eberenz

Add external radiators 2 or more make sure the original lines are the same with the radiators lines diameter. Don’t reduce the original diameter in order to connect the oil coolers

Pete
1 year ago

I have 2006 Honda Ridgeline. I was towing my ultra lite rv trailer and my transmission hot light came on. I shut down for approximately one hour and proceeded. Stayed under 45mph and drove it home. No heating no problems at all. What now? Obvious to me is get expert to check. What should I expect? Is transmission repairable or even needs repair? Would adding a transmission cooler be recommended?
Thank you

Hunter V
5 months ago
Reply to  Pete

Add oil cooler and no more problems.
Check the original lines diameter don’t reduce it.

Susiku mwanangombe
1 year ago

I just changed the transmission fluid but the vehicle is failing to engage other gears and I temperature is moving up so fast

Justus Chandrabose
1 year ago

You should use the transmission fluid as per the specification of your car vin number and purchase from the agency, replace filter too..

William Clements
2 years ago

truck runs fine when cold. When it gets hot after running a while the transmission binds, wont move forward or reverse. Has transmission cooler. Please, if you have any ideas. I’ve had it in the shop twice, over $1000. and same problem

John
1 year ago

I have o7 chevy silverado changed torque convertor, solonid, catalytic converter, new senors, computer & when i plow a couple small bussiness the transmisson gets hot what could cause this

Justus Chandrabose
1 year ago

Purchase oil from the agency as per vin number and replace the filter too..

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