Does spinning wheels in snow damage the automatic transmission?

And if so (assuming everything seems to be running well for now, at least), should the transmission fluid be changed ASAP, to prevent even further damage?

It is unclear how much spinning you are talking about. Rocking the car to get out of the snow has never caused me any transmission damage, but you should look at the trans fluid, any color other than normal is the first sign you need a fluid change, if not service.

Not just spinning the tires in snow will damage the tranny. But if you get stuck in snow, and use the tranny to rock the vehicle back and forth, that can cause overheating of the tranny.

Tester

Also, if you’re rocking yourself out, you need to make sure you press the brakes before shifting so you’re not slamming it into reverse while the wheels are spinning forward or vice versa.

Thanks for that, over looking the obvious to me!

For a long time maybe but the spinning is usually causing the differential to work harder. If you did it back and forth for four minutes, you are OK. Your car too.

Ok, this is more complex than I thought, so I’ll describe exactly what happened. The car is a 2006 Subaru Outback AWD. With good traction, most of the power goes to the front, but the transmission will also send power to the rear as needed. I was turning around in a parking lot, and got stuck (wheels spinning) in an area where the snow was a little deeper. I gave it a lot of gas (whech reved the engine) and was free within seconds. Total time for everything was well under a minute, and I never tried rocking the car. But just after freeing the car, I noticed a slight burning smell. Today, the car is driving fine, as if nothing happened.

A Word Of Caution: As We Always Say, Look In The Owner’s Manual.

Cars have differentials that allow the drive wheels to spin at different rates to prevent the tires from scuffing, especially while turning. Also, they equal out the torque delivered to both drive wheels. So if you have one wheel spinning on ice / snow, the other one that is not stuck doesn’t have the torque to move the car, and there you are, stuck in one place.

Most regular 2-wheel drive cars have this type of differential that lets one wheel spin if it’s on ice or in the air. The problem here is that the speed of the ring gear in the differential is the “average” speed of the two drive wheels or axles.
So if the gripping wheel doesn’t turn and the non-gripping wheel just slips and spins, it can turn at twice the speed indicated by the car’s speedometer. When the speedometer says 60 mph, for example, one wheel may be turning at the incredible speed of 120 mph! That’s just at an indicated 60.

That 120 mph exceeds the speed of even some “speed rated” tires, such as “S” and “T” rated tires. Many tires are not speed rated and often recommend a maximum speed of only 85 mph!

This high speed is bad for the car and can explode a perfectly good tire. My car’s manual warns not to exceed an indicated 35 mph while stuck or you can explode a tire or damage the transaxle.

Many people carry sand or kitty litter in the winter to help get traction when stuck.

This whole warning about excessive spinning that I’ve written may not apply to this AWD Outback. Cars with limited slip or locking differentials can be an exception. The owner even says that his car can send more torque to different wheels when needed. Maybe somebody can explain how this Subaru works. Maybe somebody can check their manual and tell us what it says.

The best thing the owners can do is to read the Owner’s Manuals. They usually cover situations that pose a danger to the vehicle and its human friends.

Hmmm…If you are spinning your tires in an Outback, then I am going to guess that this is one of the Subarus that came from the factory with Bridgestone RE-92 tires. If I am correct about your car being equippe with those tires, I can tell you that those tires are essentially USELESS on slippery winter surfaces, and this is just a sample of what you can expect from those dangerous tires in winter conditions.

Even if you don’t want to go as far as I do by mounting a set of Michelin X-Ice winter tires for the colder months, I would advise you to get rid of those RE-92s a.s.a.p. Think about it–if they were spinning at low speed in snow, imagine how they will perform when you hit a patch of black ice at 45 mph. Subaru should be ashamed of itself for equipping most of its cars with those crappy tires, as even an AWD vehicle needs decent tire grip if it is to transmit power properly to the tires.

All of this being said, since the incident took “well under a minute”, it is very unlikely that any damage took place. Prolonged spinning of the tires can lead to overheating the transmission fluid, but that was not likely in such a short amount of time. Additionally, Subarus have a warning light on the dashboard to warn you of overheated transmission fluid. If that light did not illuminate, then it is fairly clear that you did not overheat the trans fluid. However, just to be on the safe side, I would advise that you check the trans fluid for both the presence of a burned smell and/or a brownish color rather than the normal pinkish-red color. (Consult your Owner’s Manual for information on how to check the fluid)

Now, do yourself a HUGE favor and get rid of those Bridgestone RE-92 tires before you have problems more significant than spinning your tires in a parking lot. If you don’t want to invest in winter tires, at least get a set of all-seasons that will handle slippery conditions properly. I recommend the Goodyear Triple-Tread tires, or if you want to spend a bit less money, the B.F. Goodrich Touring T/A tire (sold at Costco!) is a good value and is infinitely superior to the RE-92s in every way.

VDC Driver, What Does A Subaru AWD Owner’s Manual Say About Spinning?

I don’t have a Subaru Dealer within 100 miles of here and I never even see these cars.

Did you read my post (below) about spinning and wheel / axle speed ? What happens with this Subaru AWD set-up ?

Also, I don’t care how many wheels are driving, if you ride up on deep snow like we get frequently here (every other day, lately, today not withstanding), and all your wheels leave the ground, you’re stuck!

Growing up and learning how to drive in one of the snowiest (if not THEE snowiest) areas of the country I’ve NEVER seen or heard of a tranny being destroyed because of wheels spinning in the snow. But then again people there KNEW how to drive in the snow…When tires start spinning…back off on the pedal…The spinning means your NOT getting traction. Slower moving tires will get better traction.

Good Advice. If Tires Are Spinning And Nothing’s Happening, Go To Plan “B”.

The manual says:
“If you must rock the vehicle to free it from snow, sand, or mud, depress the accelerator pedal slightly and move the selector back and forth between “D” and “R” repeatedly. Do not race the engine. For the best possible traction, avoid spinning the wheels when trying to free the vehicle. When the road surface is extremely slippery, you can obtain better traction by starting the vehicle with the transmission in 2nd, rather than in 1st gear (both for MT and AT vehicles).”

So, there is good information there, including the bit about starting the car in 2nd gear. That is a great example of the type of information that people miss out on by NOT reading the Owner’s Manual.

On icy hills, I do occasionally start the Outback in 2nd gear, and the reduction in torque does essentially eliminate wheel spin, but not if you are using those awful Bridgestone RE-92 tires, due to their almost total lack of traction on slippery surfaces! I used to use this feature frequently on my Taurus and my Accord when winter conditions were really bad, and it made an incredible difference on those FWD cars. And, for the vehicle manufacturers whose vehicles cannot be started in 2nd gear, I want to ask–WHY NOT?

That being said, whoever wrote this paragraph in the Owner’s Manual left out an important detail, namely to be sure that the tires come to a complete stop prior to changing from forward to reverse, and vice-versa. However, on balance, the information in an Owner’s Manual can save a car owner from a lot of problems and a lot of needless expense.

The burning smell was probably from the tires

Most regular 2-wheel drive cars have this type of differential that lets one wheel spin if it’s on ice or in the air. The problem here is that the speed of the ring gear in the differential is the “average” speed of the two drive wheels or axles.
So if the gripping wheel doesn’t turn and the non-gripping wheel just slips and spins, it can turn at twice the speed indicated by the car’s speedometer. When the speedometer says 60 mph, for example, one wheel may be turning at the incredible speed of 120 mph! That’s just at an indicated 60.

Excellent point you bring up! I recall being told this tidbit many years ago and it was the first thing that came to mind when reading the original post. Spinning tires with open differentials can be destructive if you over-rev the engine.

Do You Know If This Applies To An AWD Subaru Or Are They Limited Slip Or What ?

I’m just really curious.

Markmast went straight to the answer. The burning smell was likely from the tires. Your comment that all is now normal, combined with your description of the incident, indicates that no damage was done.

Been there, done that, smelled the burn.

I have to disagree about the Goodrich T/A’s. I had two sets on a fwd Olds. I had belt separation on both sets before they reached 40k.

Mine have been flawless for the 5 years that I have had them on the car.

Thanks Everyone. Good thing the tires were buried in the snow like that, or they might of really gotten hot.