Slip Yoke Dust Boot?

A couple days ago as I was driving down the road, I started hearing an awful knocking sound coming from underneath the 4Runner. I still had engine power with no CEL and all tires were intact and rolling smooth. I pulled over and took a peek underneath. The driveshaft was still attached and the u-joints seemed O.K. I then noticed a little rubber dust boot on the slip yoke of the driveshaft. It was loose and there was a flap of rubber torn loose that was making all the racket. I ripped off the flap and no more noise.

Here's the question: How important is that dust boot? I don't remember my Tacoma even having one.

Here's a picture.

 

It's not important to the overall operation of the vehicle.

The dust boot will help keep water/dirt out of the slip yoke.

Over time (worst case scenario) - if water & dirt get in there, can cause the splines to rust up & fuse together and it'll no longer act like a slip yoke.

I'd get one.... can't be all that expensive. Even if you buy a toyota OEM one-piece boot....shouldn't be that hard to install. Remove the driveshaft at the flange or ujoint, disconnect the slip yoke (pull it apart), slide boot on and put everything back together (tighten everything up).

 

To add (just in case) - whatever you remove (ujoints or flange), make sure you mark its original position and put it back exactly as it was before.

If the ujoints are 180degrees out of position, you can get vibrations from that.

 

Thanks Janster, what you said is basically what I assumed.