If you look on online forums, you will come across the problem of the Chevy Silverado clunking noise when accelerating. This is an issue that is quite common with a number of possible fixes if you are to take into consideration the many YouTube videos, forums, and blog posts out there.
Some of the information is useful and correct while some of it is downright false and could possibly lead to more harm than good. In this post, we will do our best to give you correct information on the possible causes as well as the correct course of action to take in order to fix this issue the right way.
In short, the clunking sound on a Chevy Silverado when accelerating is caused by the transfer case getting into contact with the skid plate. This may be caused by a damaged skid plate bending upwards or worn out transmission motor or engine mounts causing a rattling sound.
Now, let’s take a look at exactly why this problem occurs, the reason why it happens, and how to fix it the right way.
Why Does my Silverado Truck Clunk When I Accelerate?
Many Silverado owners who have reported this issue state that it happens when accelerating while driving or taking off from a full stop at traffic lights, for example.
The sound is that of metal knocking against metal. The fixes that are peddled on the internet involve greasing the drive shaft. Though this may work on 2 wheel drive versions of the Silverado, this advice may be detrimental to a 4 wheel drive as it may contaminate the drive shaft.
You should only use transmission oil in such situations. In other cases, the drive shaft may not actually be the problem in the first place meaning that you are focusing on the wrong “fix”. So, what is the actual problem?
Causes Silverado Clunking Noise
- Skid plate and transfer case coming into contact
- Worn out transmission mounts
- Worn out engine mounts
- Misaligned drive shaft angling into the transfer case
These are the most common reasons why you may be hearing the clunking sounds from your Silverado when you are accelerating. We will now look at them individually.
Skid plate and transfer case
coming into contact On the underbelly of your truck is the transfer case. In 4 wheel drive versions of the Silverado, there will often be a skid plate that protects this transfer case.
For various reasons, the skid plate will come into contact with the transfer case. Under normal cases, there should be a gap between the 2.
If your truck hits a rock and the skid plate bends inwards, for example, there could end up being a situation where the 2 touch. In other cases, it may be something different as we will discover next.
Worn out transmission mounts
The other possible reason is the mounts on the transmission case wearing out. This then leads to it sagging and touching the skid plate. This will result in the two touching and the clunking sound.
Worn out engine mounts
This is a less common occurrence but worn engine mounts can also lead to a clunking sound. In this case, it will be more of a rattling or rattling sound concentrated where the worn mounts are located.
Misaligned drive shaft angling into the transfer case
Driveshaft misalignment may also lead to this problem. When the misalignment leads to it angling into the transfer case, there will be a clunking sound.
How to Fix Clunking in My Silverado
Now; how do we fix these problems? Firstly we will need to identify exactly the cause of the clunking by going through the possible causes listed above.
If it’s to do with the skid plate and transfer case touching, you will need to ensure that you apply a permanent and not a temporary fix for this problem.
One of the solutions suggested in the case where the transfer case and skid plate touch is to bend the skid plate inward or outward so that it doesn’t touch the transfer case.
If the skid plate is not already bent because of impact or something else, bending it will only fix the clunking sound but not the real problem.
What we mean here is that when the two touches and there is no physical damage on the skid plate, it means that the transfer case has in the actual case moved down. In this case, it means that the mounts on the transfer case are faulty and need to be replaced or fixed.
The same fix also applies to worn-out engine mounts. If the problem is caused by a misaligned drive shaft, it needs to be fixed by a qualified mechanic unless you are one or have some experience fixing cars.
The clunking sound you hear when accelerating in your Silverado can be caused by a myriad of issues as you can from this article. The key is to identify the right cause and apply the right fixes to this problem.
It has to be noted that this problem has even caused GM dealerships to misdiagnose and in turn focus on the wrong thing. If your truck is still under warranty or you are having a mechanic look at it, you may suggest that they consider the solutions suggested in this article.
Thomas is a retired Chevy Auto Technician, Father to two incredible daughters. He enjoys using his knowledge and experience to help you solve and find reliable information on Chevrolet vehicles.