posted 08-23-2016 05:26 PM                  

So off with the wheel/tire, off with the fender, off with the caliper/rotor and adapter, off the the tie rod nut and disconnect. I now was staring at the steering knuckle held together by the upper BJ and the lower BJ. I could manually take the knuckle and rotate in both directions simulating the knuckles normal range of movement. In fact disconnected from the tie rod I could move it more than it's normal range in both directions. This boot didn't look to bad. At first I thought it wasn't torn and wasn't going to change it. But after I got it cleaned off I could see a tear developing. But why??

Well....here's the reason why. Moving the knuckle several times it became obvious why the boot was tearing and leading to all our problems. Exactly what is going on is that the bottom side in the aluminum knuckle contacts the
top of the BJ boot. The knuckle upon assembly (or replacement) collapses the boot and bellows it out to a degree. That creates tension and when you turn the knuckle turn either by hand or steering wheel the tension between the two twists the top portion of the boot as it follows the knuckle. The bellowed portion of the boot is what is taking the twisting action. And that is the problem. How many hundreds of times can the boot take this twisting motion in both directions before the boot is past it's stress point and tears?

There is nothing wrong with the ball joint it self. The boot tears and is driven that way for long periods as the tear gets bigger allowing the outside contamination to enter and pollute the grease which in turn turns into an abrasive. At some time the internal ball portion of the joint ends up not being properly lubricated and can only take so much before the ball end breaks off. And that is what's happening to all of our Prowlers. Both lower joints are subjected to this so at some time both are going to eventually have boot problems. The amount of miles driven and possibly the weather contribute to this boot failure.

Once the new BJ was installed I moved the knuckle in both directions and once again observed the boot twisting and following the knuckle. So I have just basically reset the clock on this issue as we all have from the BJ recall and time of installation. As long as the boots keep twisting as they do, we are all for the most part biding our time until the boots give out again. It can be difficult to see the torn boot(s) but for me it was throwing a blanket on the ground and with a flash light got a clear view of my boot tears. The boots can give out in various places so if they tear on the side facing the wheel you won't see it from up above.

And there you have it. Until there is some fix, a Teflon washer perhaps between the knuckle and the boot maybe. I don't know. Anything to stop the excessive twisting of the boots. If you have something to say regarding this issue please feel free. If you feel I'm full of you know what, please let me know. I feel absolutely sure that this has been the problem since day one that the Ball Joint issue has reared it's ugly head.

posted 08-24-2016 03:44 AM                  

quote:

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Originally posted by RPL:
Thank you for sharing. I will take a close look first chance that I have. Your description is very clear.

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posted 08-24-2016 11:47 AM                  

My car has a little over 5k miles on it. Because I wasn't looking or monitoring the BJ boots closely enough I can't be sure WHEN they actually started to tear. I know once I removed them I looked them over very closely I found that the grease inside the boots was what appeared to be OK. In other words there wasn't much sign of out side contamination. But.....had I continued to drive the car eventually the tears in the boots would have gotten worse allowing the grease to turn abrasive and we all know the rest of the story. Both the BJ's were what I would call still normally tight.

posted 08-24-2016 06:20 PM                  

I don't believe Fiat Engineering will be looking into this issue any time soon, and the lower joint has no zerk fitting to allow one to add grease and stave off harmful corrosion of the joint. (Side bar question: Did the fender really need to be removed to R&R the lower ball joint?)

posted 08-26-2016 09:20 PM                  

Will silicone spray lubricate it to keep it from grabbing(temp solution)?

posted 08-27-2016 12:51 PM                  

As of yesterday I have noticed one other item that might be contributing to our boot problem. It's possible that the small upper wire tension ring on the top of the boot might be too tight. During replacement, as you draw the ball joint stem through the knuckle it collapses the boot from the top down. The ring now grips the lower portion of the stem and between the upper friction of the knuckle contacting the boot and the tension of the ring, those two items together might be enough the create the boot twisting that eventually leads to boot failure.

Ball joints have been around forever and we should not have to be dealing with such an elementary issue. I have never heard of ANY other automobile that has ever had ball joint failures like we are having. And this doesn't apply to just one car so you can rule out some kind of clearance issue between different years. It's a standing engineering failure that wasn't caught several years ago and not corrected.

posted 08-27-2016 02:45 PM                  

quote:

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Originally posted by mslc10:
I like the thin nylon washer idea. Bet you could make one out of a plastic milk jug , make a cut in it so it would slide in without disassembly. If it works then make it out of nylon.....

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posted 08-27-2016 10:43 PM                  

In response to the nylon washer....use two! Friction coefficient between two nylon entities is .15. Or Teflon .....04!

So who has a ball joint that can be measured for hole diameter, can calculate the thickness needed and give these guys a call?........
http://www.phoenixspecialty.com/products/washers/ptfe-washers

They can make us whatever we need! Is there a recess in the bottom of the knuckle or is it just flat where the boot contacts it?
Can someone post a picture of the bottom of the knuckle?
Friction table if your interested: http://www.engineeringtoolbox.com/friction-coefficients-d_778.html