Is a Rusty Drive Shaft a Problem? (How To Clean or Paint)
Most drivers rarely think about their drive shaft. That is until something goes wrong with it. Rust is a silent enemy of any vehicle and it will affect your driveshaft if the latter has not been properly protected against the rust.
Yes, eventually it will become a problem. Surface rust is easy to remove and your drive shaft should not be damaged in any way. However, if you let the rust go then you may be in danger of seeing the driveshaft snap when too much power is sent to the wheels.
To learn more about this topic, just continue to read our article. It explores the subject so you know the severity of this issue and can take the appropriate action. Forgetting about the drive shaft is not something you want to do long-term.
Is It Normal For a Drive Shaft To Be Rusty?
It seems to be the case. In researching this topic, all owners do not get excited when someone talks about their rusty driveshaft. In fact, they say it is quite common in states like Michigan and Florida and similar states.
The reason they say it is quite common is that Michigan and similar states place salt on the road to rid the streets of ice and snow. Then states like Florida, have a large percentage of salt in the air due to the oceans being next to them.
In other words, you will see a lot of drive shafts with rust on them. In most cases, this is surface rust which you can sand off and then primer and paint the driveshaft.
Even some well-rusted parts that look like they are as fragile as glass have been examined by mechanics and declared good for the road. There is a reason this part of the vehicle is forgotten by many owners.
It takes a very long time for rust to put any owner at risk of an accident. Many car makers do put rust protection on this part so you do not have to worry about it rusting through any time through.
Is a Rusty Drive Shaft a Problem?
Technically, the answer would be no. Under normal circumstances, your driveshaft will look rusty and be perfectly fine for over 20 years. Most often all people see is surface rust which can be taken care of very simply and the process is not that time-consuming.
On the other hand, you should not let the driveshaft rust go. Eventually, and maybe not in your lifetime, the rust will destroy this mechanical part and ruin it. Honda is one car maker that does put rust protection on this vital vehicle part.
In fact, in 2020, Honda recalled over 500,000 cars because they said the company did not adequately rustproof the driveshaft during manufacturing. This recall targeted Honda and Acura sedans and hatchbacks.
This failure was said to leave the part prone to failure and a safety hazard. But how long it takes to develop into this situation no one knows. Since different states have different levels of salt exposure, the process could take a long time or it may only take 5 to 10 years to develop into a safety hazard.
We have seen different images of rusty driveshafts and even the worst ones were not a safety hazard. By worse, we mean that the driveshaft lost volume due to rust. The mechanic that checked it out said it was okay and in good shape still.
Can a Rusty Drive Shaft Cause Vibration?
There are many websites on the internet that talk about the main problems you will have with a driveshaft. These problems are signs that the part is going bad and you need to do some repair work on them.
Vibrations are one of those signs. However, rust is not the source of the vibrations you feel. The source of that problem is that the bushings inside the driveshaft have worn out.
The wearing out of the bushings would not be caused by rust either. It usually is caused by some other source. Then if you feel the vibration when you increase your traveling speed, rust has no part in that either.
That situation is caused by the tires not being balanced. There are many 60 and 70-year-old cars that are still around and their driveshafts have not rusted to the point of being a problem.
This is being said so that you do not worry about the rust you find on the driveshaft. It is not being said so you can forget about that part and never inspect it or take care of it.
If it is surface rust, you can sand it off and paint the part to protect it against rust. You just have to be careful how you paint it and make sure to get a smooth, even coat.
How do You Remove Rust From Driveshafts?
There are different methods you can use. If the surface rust is on the part that inserts into the transmission, then you can use some steel wool and WD 40 to remove the rust.
Then, there are lots of rust inhibitors on the market that will handle the problem for you. Two that were mentioned were Por-15 which is actually a paint compound that binds with the rust and is supposed to be very strong.
The second product was called Rust-Mort and it is a clear liquid that is supposed to chemically change rust. While this discussion that brought these compounds to our attention was 15 years ago, both products are available today.
Por-15 is available at Amazon while Rust Mort is available at O’Reilly’s auto parts outlets and possibly their competitors as well. You can check for similar products that may not be as expensive as these two.
Price is only one indicator that a product does what it claims to do. Check the reviews of all of these brands to get a good idea of which one would be best for your rust situation.
As we said earlier, rust may not cause vibration but the drive train is highly balanced, and slight deviations can cause problems. Those problems would come if you put too much paint on the drive shaft yoke or you did not clean up paint blobs.
The rust won’t be the source of vibration but the cure may be. So be careful when using these types of products.
How To Clean a Rusty Drive Shaft
There are different opinions concerning this topic. The method you should use will depend on what you want the drive shaft to look like. If you want it to look factory new, then you should have a new one built and replace the older rusty driveshaft.
Cleaning rust off this part can make it look pitted and it won’t look factory new. Another method would be to use what is called Media blasting. It is a very efficient way to remove surface rust.
Then if you do not have access to that option, you can try wet sanding with 200 grit wet/dry sandpaper. It is a little labor intensive but it will allow you to stop at any time when you got the driveshaft looking like you want it to look.
One owner used muriatic acid and a lot of common sense to get the rust off his driveshaft. It may take a few applications and you need to wait a few minutes after each application for the acid to work.
Then he rinsed the acid off and dried the shaft with a towel or hair dryer, etc. After that, you need to spray on some protective compound to prevent rust from coming back.
Or you can use some of those products we mentioned in the previous section. Your budget may dictate which method you use. If you are not mechanically inclined, then take your vehicle to a driveshaft shop and let them handle the work.
Painting a Rusty Drive Shaft
This is one of the standard solutions we have come across for this problem. Many owners have recommended doing this step to help prevent rust from ever coming back. The trick is to make the coat of paint even and not lumpy or sloppy.
One owner sandblasted his driveshaft and then painted it. He reported that 25 years later, no rust has reappeared. Some people recommend spray painting the part as you can control the amount of paint a lot better.
Rustoleum was mentioned as a good paint brand to use but just about any spray paint should work. Many owners recommend the products we listed above or similar ones.
If you do not want to spend time removing the rust, those products are painted on and can be left on forever.
What you need to watch out for is if you have a steady painting hand or not. Not everyone does so painting is not a great option for them. It is said that it does not take much to throw the driveshaft out of balance so if you do not have a steady paint hand, then get someone else to do it for you.
Look for those paints that work against rust and prevent its return. Your paint store or local mechanic should be able to direct you to the right brand and type of paint for this task. Then check your budget to see if it fits in or not.
How To Get a Rusty Drive Shaft On
We should make a clarification here first. Rust on the exterior of the driveshaft, the part exposed to the outside elements is not going to be a problem. However, the yoke, the shiny part, that inserts into the transmission is vulnerable to rust and may cause you some driving problems if not addressed.
If the yoke is continuously inserted into the transmission, then it is protected from rust. The problem comes in when the driveshaft has been stored in a shed, basement, etc., for some time.
If the yoke gets rusty, then you need to clean the rust off before inserting it into the transmission. The reason you clean it off is because the rust will damage the seals touching the yoke.
Once you remove the rust, you can use 60 to 200 to 1000 grit sandpaper in stages to keep the metal nice and smooth, then you just put the driveshaft back on like you normally would.
There is no special application for re-installing the driveshaft. Just put a light coat of chassis grease on the yoke and slip it over the output shaft. Make sure to align the shaft with the alignment marks you made when you took the part out.
But, if you see the yoke with a ridge or extremely pitted marks, then you have to replace the yoke before re-installing the driveshaft.
How To Store a Driveshaft
This is very important information because rust usually comes to the yoke due to improper storage. On the opposite end of the yoke, you should wrap electrical tape over the caps to keep them from falling off. It is supposed to be a big mess if those caps come off.
Then on the yoke side, you should wrap the yoke in a rag and secure the rag with electrical tape. You do not want to damage the yoke in any way. You can lubricate the yoke with grease but most grease types contaminate the transmission fluid, clutches, and bands.
That means you have to completely remove the grease before re-installation. This should protect your driveshaft yoke from rust when not in use.
Some Additional Words
For the most part, rust on the exterior of the driveshaft is not going to be a problem. It is when the yoke gets rusty that you have to do some good maintenance work and clean it up completely.
There are products on the market to help you with this task and they are well recommended so take those into consideration when you have this problem.
