Mercedes Axle Shaft Boot Replacement

Mercedes Axle Shaft Boot Replacement

This pictorial is a slight departure from my normal ones. I like the idea of saving the DIY'ers money and will start to feature various neat tools or ideas will do just that. So lets jump into it.

Please remember to recycle all your used fluids at an appropriate recycling center. Be mindful to not spill or splash fluids on yourself, others or the ground. Also as a safety tip please remember anytime you are working on, around or under your car, to wear safety glasses and secure the car with wheel stops and approved jack stands!

Mercedes has a very robust axle half shaft as a general rule. Many cars I see in the shop still have the original axles even after 20 years. Lack of "flogging" the vehicle will generally give long service life. The weak point on any axle assembly is the rubber boot. I really don't think that Mercedes intended or designed them to last as long as we seem to use them, 20 plus years. So what happens when your boots either start to crack or rip open. Well if you get to them soon enough, then you can just "reboot" them. As long as the C.V. joint has not gotten dirt into it, then you can repack and reboot.

Buying new axles is always as option, but very expensive. Call Mercedes and check! The other option is to buy "rebuilt" axles. Basically they have new roller balls, boots, and the cage has been milled smooth. This is the problem. Milling the cage assembly, removes the super hard surface that makes the original axles so durable in the first place. Hence, rebuilt axles rarely last like the factory originals.

So if your C.V. joint is in good shape just put new boots on them. There are several ways to install new boots. Go with some of the Mercedes kits that cost over $100 for each axle, use the split boots which are just a problem waiting to happen, or use the neat Flexx gun and boots from Astoria. We did one axle in less than 10 minutes which included repacking the C.V. joint and installing both boots and clamps.

Typical cracked Mercedes boot. This one still had the original liquid oil in the joint. The C.V. joint was fine, but the boot was ready to tear. This is actually a really nice boot to be 20 plus years old.

The other end of the axle is just the same, cracking but still holding the fluid. This is the best time to change the boots, BEFORE they bust.

Cut the boot off and do this over a drain pan. The joint is full of oil and will make a big mess if you do not catch it.

Tear the boot away and cut off the metal stiffening ring, which is no longer needed.

Close-up of boot. The boot is more flexible than a new Mercedes boot, and is sized to fit a variety of axles.

This is going on the axle, on each end. Boot kit contains grease for packing the joint, boot and clamps.

This is the machine called the Flexx gun. It operates off your air compressor.

...and pull the trigger. When you get to this point, just slip it over the axle joint and release the air. No the boot is not going to break, its designed to do this.