Question:

I think my Bronco has clutch chatter. How can I be sure that this is my problem and what should I do to fix it?

Answer:

Although it is possible for the early Bronco to have problems with clutch chatter or otherwise known as "Bucking Bronco Syndrome" you must be careful to not automatically assume that this is your problem. The most common reason that people assume that they have clutch chatter is a vibration that occurs during acceleration, but this problem can also relate to several other problems that occur in the Bronco. So before you go out and buy a brand new clutch, please consider the following possibilities. Might save you some money!

Why do you think you have clutch chatter?

There are a couple of reasons that may lead you to believe that you have clutch chatter.
#1) Your Bronco vibrates when you accelerate.
#2) You may here a clunking sound that seems to be coming from underneath the Bronco.
If you are encountering either of these problems, you may have a problem with your clutch or you may not. Please read on.

What to look for before assuming it is clutch chatter:

1. Axle Yoke - You will begin your search for the problem at the rear of the vehicle. Start by checking the yoke on your rear axle. Is it loose? Have the bearings gone bad?

2. Drive Shaft - Now you will move up the length of the driveshaft. Inspect the U-joints, the CV-joint, and the slip shaft for excessive wear or looseness.

3. T-Case Yoke - From the driveshaft, we will move to the rear t-case yoke. Check here for a loose yoke and/or bad bearings. Also check to see that your U-bolts are tight.

4. The Test Drive - If you haven't located the problem by now, then you are going to need to grab the keys and go for a ride. But hold on! Before you light up that motor, you will need to do a few things first. Start by taking off the rear driveshaft. Now lock in the front hubs and take a spin around the block. If you do have clutch chatter it won't matter whether you are in front or rear wheel drive, the problem will still persist. On the other hand if the problem was related to the rear driveshaft and yokes, then the chatter would disappear during the test drive.
Still have clutch chatter after this little joy ride? Well, I guess we better talk about solutions.

How to Fix

The first area that you will want to look at is the face of your clutch. You will need to remove the disc to inspect it. If it has oil on it, that may be your problem. This can be caused by a leak in the main seal. You will definitely need to replace your seal if this is the problem.
Also check the transmission input shaft seal. It also may be worn out.
Now take a look at the splines on the clutch gear. Are they worn out?
Also check to see if the pressure plate or flywheel is warped. This can be caused by extreme heat.
If any of these problems show up, then most likely this is the source of your clutch chatter. The answer to your diagnosis of the problem is very simple. Buy a new clutch! Be sure to have the flywheel resurfaced when installing a new clutch!

Happy wheeling!