GMC Acadia Transmission Shudder – What's Wrong and How to Fix

The GMC Acadia was introduced in 2006 as a 2007 model year. It was designed to be a more fuel-efficient alternative to other full-size GMC SUVs. The vehicle was built on the then-new four-wheel-drive Lambda platform, featuring an optional all-wheel drive drivetrain and several V6 engine options. These features made the Acadia the choicest option for buyers looking for full-size SUVs with reasonable fuel efficiency.

GMC Acadia automatic transmissions highlights

• Average lifespan:190,000-220,000 miles
• Reliability Score:High
• Prone to minor issues:Sometimes
• Price for repair after failure:$1,000-$2,000
• Price for replacement:$4,500-$6,000
• Availability of parts:Average
• Common problems:shuddering transmission, vibrations, harsh work, shifting issues, sudden failures, electronic glitches.

What's Transmission Shudder?

While many people have experienced this problem, most of them don't know what to make of it or what to call it. You may have heard another driver or mechanic talk about transmission shudder. Also known as torque converter shudder, transmission shudder is when the transmission in your Acadia causes the vehicle to shake or tremble convulsively. In many cases, transmission shudder happens if or when you drive up an inclined road with the overdrive gear engaged. It can also occur when shifting to overdrive.

Transmission shudder is often caused by internal clutches locking up inside the transmission. Many mechanics will overlook this problem, more often confusing it with a much bigger problem with your Acadia's transmission. It is a serious mistake because it can leave you with massive and unnecessary repair bills.

If you notice your SUV convulsively trembling and have no idea what's happening, don't do what everybody else does; don't panic. Instead, call your nearest GMC service center for advice. It is not as bad as your vehicle makes it look. It feels like the whole transmission system is shutting down. However, that's not the case.

GMC Acadia Transmission Shudder - Common Causes

Is your Acadia shaking convulsively? It feels like the whole transmission system is damaged and about to shut down completely. The primary cause of transmission shudder is contamination in the transmission fluid.

Contaminants inside the transmission fluid, whether dust or metal shavings, rust, or water, prevent the required pressure from building up within the transmission lines. This inhibits the transmission plates from getting enough pressure contact, which results in transmission shuddering. Low ATF level is also another possible cause of transmission shudder.

While it may sound like a life-and-death problem, regular maintenance can easily prevent the GMC Acadia transmission shudder. Do you know how often you should change the transmission fluid in your Acadia? Your GMC mechanic is the right person to schedule the transmission fluid change intervals. Unfortunately, many manufacturers won't tell you when to change your ATF. You have to wait until there's a problem.

Automatic transmissions, much like the GMC Acadia, generate more heat than manual gearboxes, degrading the transmission fluid faster. That means the fluid in your Acadia automatic transmission will get contaminated much quicker than you expect. This means you should change the fluid regularly, even before the transmission develops any noticeable issues.

Commit to regular transmission services to avoid surprises on the road. It is cheaper to run transmission diagnosis regularly than to pay for transmission repairs. It is during these service visits that you have the fluid levels and transmission plates checked.

Is Transmission Shudder Something You Can Fix From Home?

Yes. Absolutely. If you have soem skills as a car mechanic.

As long as you are the type that likes to get your hands dirty, fixing your Acadia from home should be an easy task. It is not one of those simple do-it-yourself home mechanical hacks, but with the right tools, you can fix your GMC Acadia transmission shudder.

Many people confuse transmission shudder for a dying transmission unit. As a result, they end up spending more than necessary. It does not require you to replace or rebuild the whole transmission system to eliminate this small problem.

Step By Step Guide to Fix Transmission Shudder on Your Acadia

Attention! We don't want you to do anything from the list below unless you have some skills as a car mrchanic. Be careful and never do anything with your car if you are not completely sure you can do it correctly.

• The first step is to jack up the front end of your SUV. You will need to have jack stands in place to keep the vehicle steady. Safety is key. You have to be sure the vehicle is stably raised before going under it. This is an essential safety hack. But since not everybody likes to work on their vehicles, we have to address it like we're addressing a beginner.
• The next step. This is where you locate the transmission pan and remove its bolts using a socket wrench before draining the ATF into a drain pan. The GMC Acadia has a drain bolt on the pan. Use this to drain the fluid before removing the pan. You can always refer to the manufacturer's manual if you bought a new Acadia.
• Once you've drained all the ATF and removed the pan, the next step is to clean the pan and replace it. You'll also need to install a new transmission gasket. Please pay close attention when removing the old gasket to ensure it is scraped off completely. You may need a gasket scrapper if you are going to do a perfect job here.
• Time to replace the transmission filter - or not. Whether you replace the filter entirely depends on the state of the ATF and your judgment. If the old transmission fluid looks clean, you might not need to replace the filter. This could also mean that the transmission shudder problem isn't coming from the fluid since it's not contaminated. However, the transmission filter cannot clean the fluid if the ATF is noticeably dark. It should be replaced, especially if you are driving a high-mileage Acadia and haven't replaced the filter in a long while. Since you are down there already, replacing the transmission filter will bring you more blessings than curses. Generally, the GMC Acadia transmission filter requires a replacement every 30,000 to 50,000 miles, costing around $30.
• Now that you have treated your Acadia to a new gasket and filters reattach the transmission pan, and lower the vehicle by removing the jack stands.
• Pop the hood - it's time to replace the ATF you drained with a brand-new one. Remove the dipstick and place a small funnel into the dipstick tube to guide the fluid into the transmission. To ensure you don't miscalculate, put the fluid you drained into a measuring jar to replace the exact amount - especially if you didn't have problems with transmission fluid levels.
• Put the dipstick back, cover the hood, and start up your Acadia. Give it time to heat up to the required temperatures. Once the engine heats up, pop the hood again and remove the dipstick to check the ATF levels. You can increase the fluid to the proper levels if the level is not where it's supposed to be. Since the primary and common cause of transmission shudder is contaminated transmission fluid, your GMC Acadia should be free of the problem. Clean ATF, new brushes, and a new gasket allow the proper pressure to build up between the plates when you shift.

Is That All?

It could be. However, transmission shudder can be caused by other issues. Cleaning the ATF and ensuring the plates are in a suitable environment is the most affordable fix that always gets the job done. But, there could be a deeper mechanical problem with the transmission.

If you have gone through the above process and still have your GMC Acadia experiencing transmission shudder, it's time to visit your nearest GMC mechanic. You should have a mechanic run a complete transmission diagnosis to root out any possible causes of the problem.

The goal of starting with the transmission fluid fix is to avoid expensive and unnecessary repair costs that could otherwise be avoided. That doesn't entirely rule out severe problems within the transmission.

Final Thoughts

Transmission shudder is one of the scariest transmission problems with the GMC Acadia SUV. And although it's not as severe as it seems at first, no one wants to experience such convulsing, especially during a hill climb where the vehicle could roll back uncontrollably. Experiencing this problem is like coming face to face with a gun, only to find out it's loaded with rubber bullets. It can inflict pain, but it can't really kill you. That's what transmission shudder does to your mind.

It is one of the cheapest problems to fix in your GMC Acadia. While there are expensive fixes to try, the first one is a simple DIY -change the oil, do a little cleaning, and the problem goes away. If it doesn't disappear, then you can visit a GMC mechanic.