OK guys, few and far between am I not able to figure things out and this one has me at a loss. I spent most of my free time yesterday and today searching and reading the FSM, and after coming up with dead ends, it's time to make a post about what I have going on. I'll finish my preamble with expressing my disdain for "my truck makes a noise, what is it?" threads because they're almost impossible to diagnose over the internet but unfortunately, here I am. And so, I've made this as detailed and thorough as possible so you can get an idea of what I've done and what the truck is doing. It's a long read, so grab a beer or a bong or some holistically raised free range gluten free organic water or whatever floats your boat before we begin.
I recently bought a 40th Anniversary with 268k to be the replacement for my '95. About two days and about 100ish miles into ownership, the truck developed a clunk in the front left that corresponded with a thump felt in the drivers foot well down by the body mount. Initially, I thought it was a loose shock as my '95 did that when I first got it. However, the 40th also clunked upon application of the brakes and then began to creak at odd times. It sounds more like a creak you'd get from dry ball joints, or similar to the creaking brakes make when you just barely let off the brake enough to begin to creep forward. Most of the time, it'll creak when turning the steering wheel at any speed, with or without throttle or brake. Sometimes, it'd do it when hitting the gas from a stop. Rarely, it'd do it while weaving back and forth in my lane. The only consistent way to replicate the noise is to use the brakes; every time I step on the brake, it makes the creaking/ thump. It is not the clicking of a birf, or at least none that I've ever heard come from a birf or a CV joint in 30 years of turning wrenches. So, I went in to see what was up.
First off, the shocks, the suspension bushings, the wheel and trunnion bearings, the sway bar end links, the caliper bolts and the steering gear are all tight. I've checked them several times both with the axle supported on jackstands and with the frame on stands to take the weight of the truck off the front end. With the weight off the suspension, I turned the steering wheel slowly to listen for a dry tie rod end. I also had my girl friend do this with the truck on the wheels, but with the engine running, I couldn't hear anything. But like I said- the steering gear is tight. Long story short, everything in the front end outside of the axle is solid and the truck, other than the creak heard and thump felt, drives and brakes as it should.
However, I did find two things thus far...
The brake pads. As I said- the PO did the brakes relatively recently. He didn't mention this and I only discovered it when I went looking for the cause of the noise. Here's where it gets weird... The Bosch brake pads are overlapping the top of the rotor like they're not sitting down in the caliper far enough. I've seen this on sliding calipers, but never fixed calipers like what we have, where the pins going across the top of the pads dictate how deep they sit in the caliper. Thinking the pads might be the wrong pads, I bought some cheapie Autozone pads to see how they compared to the pads in the truck, and they're identical, and even sit in the caliper the same with about 1/8" of friction material above the edge of the rotor. Additionally, both the Bosch pads and the Autozone pads have some lateral play when they're inside the caliper- when the caliper squeezes the pads, the rotor will pull them slightly to one end of the caliper or the other, depending on which way the axle is turning. I'd say this movement is a little less than 1/16". Since the caliper is fixed in place and the pads are held in with pins, is there any possible way that an FJ80 rotor was installed instead of an FZJ80 rotor? I know the FJ80 rotor is smaller, but am not sure by how much or if it'd even be possible to install it on an FZJ80? And since it's been a long while since I did the brakes on my '95, is this lateral pad play inside the caliper the norm? I don't remember it in my '05. Oddly, the passenger side pads have the same play and overlap, but the creak/thump isn't coming from that side of the truck. I didn't get pictures of the pads, but here's a picture identical to how they're wearing.
The knuckle. I intended to pull the knuckle apart this afternoon to check the birf and everything else in there, but weather closing in prevented me from getting very far. I was able to pull the top trunnion pin and look in to see almost no grease. After pumping in two 14 oz. tubes of grease, I pulled the drive flange real quick to see if the wheel bearings even had grease on them. They do, but I noticed the axle shaft moved around quite a bit inside the spindle. I know the inboard end is supported by the spindle bushing and the outer end is supported by the drive flange, but I was able to easily wiggle the end of the axle back and forth to make contact with the lip of the spindle. As with the brake pads, it's been a while since I've been in one of these axles, so I can't recall if this is normal or not.
My thoughts are that perhaps the birf is bad, the spindle bushing is bad, or that the rotor is incorrect. Unfortunately, I haven't been able to get into the knuckle so until I get a chance, I'm hoping you guys can chime in on the brake pad issue at the very least, if not your thoughts and suggestions.
I recently bought a 40th Anniversary with 268k to be the replacement for my '95. About two days and about 100ish miles into ownership, the truck developed a clunk in the front left that corresponded with a thump felt in the drivers foot well down by the body mount. Initially, I thought it was a loose shock as my '95 did that when I first got it. However, the 40th also clunked upon application of the brakes and then began to creak at odd times. It sounds more like a creak you'd get from dry ball joints, or similar to the creaking brakes make when you just barely let off the brake enough to begin to creep forward. Most of the time, it'll creak when turning the steering wheel at any speed, with or without throttle or brake. Sometimes, it'd do it when hitting the gas from a stop. Rarely, it'd do it while weaving back and forth in my lane. The only consistent way to replicate the noise is to use the brakes; every time I step on the brake, it makes the creaking/ thump. It is not the clicking of a birf, or at least none that I've ever heard come from a birf or a CV joint in 30 years of turning wrenches. So, I went in to see what was up.
First off, the shocks, the suspension bushings, the wheel and trunnion bearings, the sway bar end links, the caliper bolts and the steering gear are all tight. I've checked them several times both with the axle supported on jackstands and with the frame on stands to take the weight of the truck off the front end. With the weight off the suspension, I turned the steering wheel slowly to listen for a dry tie rod end. I also had my girl friend do this with the truck on the wheels, but with the engine running, I couldn't hear anything. But like I said- the steering gear is tight. Long story short, everything in the front end outside of the axle is solid and the truck, other than the creak heard and thump felt, drives and brakes as it should.
However, I did find two things thus far...
The brake pads. As I said- the PO did the brakes relatively recently. He didn't mention this and I only discovered it when I went looking for the cause of the noise. Here's where it gets weird... The Bosch brake pads are overlapping the top of the rotor like they're not sitting down in the caliper far enough. I've seen this on sliding calipers, but never fixed calipers like what we have, where the pins going across the top of the pads dictate how deep they sit in the caliper. Thinking the pads might be the wrong pads, I bought some cheapie Autozone pads to see how they compared to the pads in the truck, and they're identical, and even sit in the caliper the same with about 1/8" of friction material above the edge of the rotor. Additionally, both the Bosch pads and the Autozone pads have some lateral play when they're inside the caliper- when the caliper squeezes the pads, the rotor will pull them slightly to one end of the caliper or the other, depending on which way the axle is turning. I'd say this movement is a little less than 1/16". Since the caliper is fixed in place and the pads are held in with pins, is there any possible way that an FJ80 rotor was installed instead of an FZJ80 rotor? I know the FJ80 rotor is smaller, but am not sure by how much or if it'd even be possible to install it on an FZJ80? And since it's been a long while since I did the brakes on my '95, is this lateral pad play inside the caliper the norm? I don't remember it in my '05. Oddly, the passenger side pads have the same play and overlap, but the creak/thump isn't coming from that side of the truck. I didn't get pictures of the pads, but here's a picture identical to how they're wearing.
The knuckle. I intended to pull the knuckle apart this afternoon to check the birf and everything else in there, but weather closing in prevented me from getting very far. I was able to pull the top trunnion pin and look in to see almost no grease. After pumping in two 14 oz. tubes of grease, I pulled the drive flange real quick to see if the wheel bearings even had grease on them. They do, but I noticed the axle shaft moved around quite a bit inside the spindle. I know the inboard end is supported by the spindle bushing and the outer end is supported by the drive flange, but I was able to easily wiggle the end of the axle back and forth to make contact with the lip of the spindle. As with the brake pads, it's been a while since I've been in one of these axles, so I can't recall if this is normal or not.
My thoughts are that perhaps the birf is bad, the spindle bushing is bad, or that the rotor is incorrect. Unfortunately, I haven't been able to get into the knuckle so until I get a chance, I'm hoping you guys can chime in on the brake pad issue at the very least, if not your thoughts and suggestions.
