My brake pads destroyed my knuckle mounting ledges

[RCP Phx]

Don't weld on them, no weld shop that knows the law will weld on them.
The weld will crystallize the metal and cause them to snap off.

Does this mean your knuckle C's are going to fall off,Dana welded them to the axle tubes???

 

[dumbagain]

i've got the same grooves on my 97 xj. i swapped out to really good rotors and pads.

i think thoses grooves are the cause of my intense squeeky brakes.?.
does anybody elses squeel? especially when they warm up?

 

[Rick Anderson]

Does this mean your knuckle C's are going to fall off,Dana welded them to the axle tubes???

We don't even know how little we actually know about welding.

There all sorts of effects and reactions to the heat and different metals used for the filler wire, there is so many different variable in the process that can be used to address those problems and counter-act the negative effects. Things we barely even scratch the surface on. So there is a big difference between a true Professional or Engineered Manufacturering Process that welds Cast Iron that know all about the metallurgy and an Ameature that just knows how to work the welder and lay a bead down.

What I'm getting at:
*I would NOT be surprised if an ameature tried to weld Knuckle "C"'s on an axle (a huge weld effecting the whole casting) that he ended up causing some sort of effect or reaction that would cause them crack or snap right off. There are legitimate concerns about welding metal and how strong or tempered it will be afterwards, especially in high stress situations.

*At the same time, what we are talking about, filling a small depression with welding wire on a very large casting, I have to agree, its unlikely to create some sort of negative effect that messes up the structural integrity of the casting. The 4 or 5 people swearing they have put years and thousands of miles on this fix without problems is more evidence that weld fix for this works and is NOT critical to be done with total perfection and understanding of everything involved. i.e. an ameature can lay down a bead to fill it in and NOT mess up structural integrity of the surrounding cast iron.

i've got the same grooves on my 97 xj. i swapped out to really good rotors and pads.

That is what I am wondering, is this the result of using inferior quality pads and lack of lubrication of the rails?? I've never had this happen on any other vehicle I have owned, even in my early years when I did a brake job and did NOT lube up the rails and contacts points with synthetic brake grease.

My used XJ brakes wear totally dry, no lube on those rails at all, I'm hoping keeping some synthetic brake grease on those rails prevents a re-occurrence.

As well, NAPA sells Spring Clips for my Vehicle ('95 Cherokee) I have the composite rotors. I don't know if that is because the clips are OEM on the other brake option, or if they are a retro-fit to help combat this problem? I imagine a spring clip might help, it would push back on the contact point on pad, perhaps hold it off the rail when the brakes were NOT in use. That might be where the wear comes from, just vibrating while the pads are riding on the rotor, not being used. Or it could be when the brakes are being applied, which springs clips aren't going to do anything.

 

[dumbagain]

i bought napa ceramic pads and they did not come with any type of clip to go over that area, i was hoping they did.

i've did some research on other websites and have found that this is a common prob on xjs. the 90 yj i had for 11 years never had the problem.

but i the squeeling that i get is definetly coming from the driver side front brake and thats were the grooves are at.

 

[RockTracXJ]

I just got back from the junk yard. I picked up the knuckles off a 97 that had minimal grooves worn into the ledges. $30 for the pair; can't beat that with a stick. As I was walking around looking at the other Cherokees and Grands I looked at their knuckles and most (all) of them had the grooves to some extent.

 

[EricsXJ]

Just chiming in to say I've also welded those grooves on mine with no ill effects.

 

[sflier]

You can get the "spring" kit almost anywhere by ordering the front caliper hardware kit (~$4.00US). It also includes the rubber boots for the caliper bolts. The spring is technically an anti-rattle clip and is OEM on at least the '94-'96 years that I've worked on (it's even listed in the OEM parts manual). They help prevent the click-click noise when you apply the brakes but I suspect they help slow down or prevent the worn ledge problem. These clips are not included with brake pads nor do most people (including brake centers) install them. IMHO ... I suspect many brake noise issues and odd wear problems would be avoided if people just installed these clips. The FSM, Chilton's and Haynes manuals all show pictures of these clips as well as a visual showing how to install them.

 

[slider]

another welded knucke here. about 50k miles ago, the harder areas from the weld have not worn into new grooves so i guess i'll keep it that way.

 

[Rick Anderson]

Well Fellas; I just did my Knuckle Mounting Ledges Today. Some pics are from the Passenger's Side and some from the Driver's Side, so don't get confused, I switch back and forth.

Damaged Knuckles:

Cleaned Up & Prepped for Welding:

Welded Up:

Ground & Filed into Shape:

Brakes Assembled & Lubed with Synthetic Brake Grease & Anti-Rattle Clips from NAPA:

I haven't test drove it yet, I still have to get the manifolds and exhaust on the engine, the cooling system back together, the rest of the suspension finished and re-install the interior.

 

[Ecomike]

I am no expert on this (as I have done them wrong 3 times before I figured it out myself ) but those anti-rattle clips do not look like they are installed correctly on the finished assembly photo! Perhaps that is what damaged the knuckle to begin with?

It would be great if some one had a drawing or picture of how they should look and how they should be installed. I don't think they were installed correctly on either of my jeeps when I bought them, which is what led me astray in the first place. I do know from experience that there are four ways to install them make them look like they are installed correctly, but three of them cause brake problems.

If yours are installed correctly :banghead:then I still have a pair on one of my jeeps I need to fix! Noticed them yesterday while fixing a flat and they were installed differently than the picture......

edit.....OK, I just read the rest of the post here, I took sflier's advice and pulled out my Hayne's manual, and sure enough that is where I figured out how to install them correctly last time. The Haynes picture is exactly like the picture in Rick's photo so he does have them installed right. I also remember that they were tricky to hold in position while assembling everything if you installed them correctly! Guess I still have a pair on the second jeep to check here.

Both my jeeps have about 250,000 miles on them with out the grooves. They had clips on them when I bought them at about 200,000 miles.

 

[Rick Anderson]

...but those anti-rattle clips do look like they are installed correctly on the finished assembly photo! Perhaps that is what damaged the knuckle to begin with?...

Your phrasing has me a little confused, did you make a typo? I'm not sure if your saying I did it CORRECTLY or your suggesting I may have installed the anti-rattle springs INCORRECTLY, but made a typo?

My XJ had NO anti-rattle clips installed on them, as well, the mounting ledges (all the contact points) were as dry as a bone. I'm sure that contributed to the damage as well.

The Photos in my Haynes Show how to install the springs, and they look just like how I did it in my Photo. Although, the Haynes Manual example appears to be the cast rotor brakes and mine are composite rotor brakes. I would think the springs should be installed the same way though.

 

[Ecomike]

Your phrasing has me a little confused, didyou make a typo? I'm not sure if your saying I did it CORRECTLY or your suggesting I may have installed the anti-rattle springs INCORRECTLY, but made a typo?

My XJ had NO anti-rattle clips installed on them, as well, the mounting ledges (all the contact points) were as dry as a bone. I'm sure that contributed to the damage as well.

The Photos in my Haynes Show how to install the springs, and they look just like how I did it in my Photo. Although, the Haynes Manual example appears to be the cast rotor brakes and mine are composite rotor brakes. I would think the springs should be installed the same way though.

Sorry, it was a typo and I used edit a bit later to correct it, probably while you were typing your reply to me. I also figured out I was wrong after reading and seeing the Haynes photo and added another paragraph during the edit saying you have them on right.

You do have them on right!

Mine were dry and are and have been dry, but they had clips on them when I bought the jeeps. They already had 220,000 miles on them when I bought them, and I have added about 25,000 miles to both since then, so I know little about the prior 220,000 miles. I am thinking the grooves are caused by not having the clips. Mine do not have the grooves.
Either way you have it covered now! Looks like your "Good to Go".:clap:

 

[RockTracXJ]

To clip, or not to clip, that is the question.

My Haynes does show the 'anit-rattle' clips, but it looks like they are on an older model XJ. The brake pads in their photos do not connect to the caliper like Rick's and mine, so I assumed it was the older style. And perhaps that is why they needed those clips. Also, my FSM does not show or mention anti-rattle clips! I just re-assembled my Jeep tonight and was going to put the clips on, but decided I would have to be Houdini to get the clips on. I tried a couple times, but it was a pain in the arse, they kept falling off. Rick, you must be the master to be able to get those things on there. Good job on fixing the grooves, too. I can't weld, so I just pulled some knuckles from the junk yard.

 

[Rick Anderson]

Yea, I didn't think of that until you mentioned it. The later Brakes have the pads clipped to the calipers. So the caliper should hold the pads in place, the caliper bushings should act like the springs.

Still it can't hurt. I look at the little clip springs holding the pad off the mounting ledge unless you actually brake and then the forces compress them. The caliper bushing with the pads clipped to the caliper probably do the same, but it doesn't hurt to have a little help from the clipped on springs.

 

[thall]

I have seen a different setup than the antirattle clips shown on page 2.

replaced front pads on a friend's 95 xj, believe he brought raybestos pads. inside were thin formed 'shims' (for lack of better word) of varying thickness.

these were long and shaped to fit over the contact surface for the pads.. they are much longer than the pads.

don't have an image of them, and do not have them here...

certainly looked to me as their purpose was to
a. create tension on the pads to stop rattle, squeak
b. create a new thrust surface on the pad contact surface, bridging the worn spots

I just installed pads on my zj, and could not find these devices to use. i checked quite a few brands of pads... i used AZ performance friction for first brake job at 72k... and at 150k AZ no longer stocked PF pads, so they subbed Duralast Gold for the replacement (free) neither had the device i am speaking of...

for now... i blended the grooves as to not have a sharp edge and used synthetic brake grease on the surfaces, but maybe not to the extent i seem to see in the images

with using the grease... how do y'all feel about its attraction to dust, dirt, sand, etc ? could this not cause additional wear?

 

[Rick Anderson]

...i blended the grooves as to not have a sharp edge and used synthetic brake grease on the surfaces, but maybe not to the extent i seem to see in the images

with using the grease... how do y'all feel about its attraction to dust, dirt, sand, etc ? could this not cause additional wear?

6 of one, a half dozen of another.

The brake parts don't move enough to do any mixing action with the grease, so I'm guessing any dirt that is caught in the grease should mostly lay on the surface. Hopefully the movement of the brakes will scrape away the upper layers of grease and only the lower clean layers get inducted under the moving parts.

Also, don't forget, water also washes away the grease you put down. A light layer of grease may get washed away.

I've always found the brakes on other vehicles work better with less noise using grease. I've found some pretty dirty grease, but never any damage or wear. But, then again, I've never found any wear on mounting ledges for pads till I got an XJ. My XJ brakes were bone dry BTW.

 

[montanaman]

To clip, or not to clip, that is the question.

My Haynes does show the 'anit-rattle' clips, but it looks like they are on an older model XJ. The brake pads in their photos do not connect to the caliper like Rick's and mine, so I assumed it was the older style.

I just dealt with this same thing on my '91. I have the newer-style pads that attach to the calipers. I first mounted them without the anti-rattle clips on the knuckle, but they vibrated really bad at about 63 mph. Did it over with the anti-rattle clips on there, and they calmed down immediately.

When I took the caliper off for the second try, I realized the caliper floats a lot more than I expected. Not just lateral (in and out) movement as you would expect, but also up and down movement. The rubber bushings are pretty thick ... they go completely thru the caliper mounting holes, and the bolts go through the rubber bushings. That allows the caliper complete "rubbery" movement. You can verify that yourself ... mount the caliper with no pads, tighten down the bolts, and wiggle it around. It will go up-down, in-out, and front-back. That's just the way it's designed.

So you can't really expect the caliper to hold the brake pads in the proper position. The pads have to have a decent connection to the knuckle mounting ledges to hold them in place. That's what the anti-rattle clips do.

I almost think it would be better to stick with the older style -- to *not* have the brake pads attached to the caliper ... just let them ride on the knuckle mounting ledges with the anti-rattle clips, and let the caliper ride freely over the pads (as shown in the haynes manual).
.

 

[alfman]

The parts lonestar got were on an 87 (if I read his post right) & were the removable slides on the older units. I believe 90 & up are the same all one piece knuckle & slide (although I don't remember how far up past 94). 88 & earlier are the 2 piece knuckles with removeable slides. I don't know on the 89 model as I haven't pulled that one apart yet. The axel housings & knuckels are different between the early & later years, so you can't put the earlier knuckles on the later axels (I confirmed that with my buddy in the dealer parts dept).

I have 2 90's (one for parts) an 89 & an 87 & just added a 2000 to the stable. I found out the hard way after trying to repair the 87 with parts from the 90 parts unit.

If I were you I would go the welding route myself, but it's what your comfortable with.

 

[Rick Anderson]

...When I took the caliper off for the second try, I realized the caliper floats a lot more than I expected. Not just lateral (in and out) movement as you would expect, but also up and down movement. The rubber bushings are pretty thick ... they go completely thru the caliper mounting holes, and the bolts go through the rubber bushings. That allows the caliper complete "rubbery" movement. You can verify that yourself ... mount the caliper with no pads, tighten down the bolts, and wiggle it around. It will go up-down, in-out, and front-back. That's just the way it's designed.

So you can't really expect the caliper to hold the brake pads in the proper position. The pads have to have a decent connection to the knuckle mounting ledges to hold them in place. That's what the anti-rattle clips do...

I got a $5 kit from NAPA that has both new Bushings and Spring Clips, the picture is deceiving, there is only enough for one wheel per box, not the whole axle.

The fresh bushing are firmer than the old ones I pulled out and they do seem to firm up the caliper as well. But the calipers can still move around like you observed, I can't see how having the clips can hurt and likely could help, sounds like they did in your case, so I'm keeping the clips on, as well I'm hoping the fresh caliper bushings, quality pads, repaired ledges and grease will smooth out the brakes considerably.