Solid clunk from drivers front disc! Possibly serious?

[Landcruisin60]

So it just started today. When you first put your foot on the brake you get a little clunk, you can hear it and feel it through the pedal. The brakes are also making a bit of a grinding noise while slowing down, maybe related maybe not. It almost seems like the rotor spins just a little until the wheel studs stop it from spinning any further... is that possible? I've heard horror storys where that happens and it shears the studs right off and I dont want that happening.

Thanks

 

[MAKG]

It's possible if your lugnuts are loose. Easily checked.

 

[Landcruisin60]

First thing I checked. Torqued to 90ftlb, is that not enough?

 

[Robin Hood]

i believe it is supposed to be 100 (i think) but 90 isn't going to cause that.

What happens to the pedal when you hear the sound?

 

[metalmacguyver]

i always go to comfortably tight. for me thats way over 90 or 100ft lbs.

pull the tires and take a look at the brakes. look for anything thats loose or broken.

 

[Landcruisin60]

I just pulled it off again and checked and everything looks good. Are the holes in the rotors supposed to be pretty oversized compared to the studs? I just feel a little pulse through the pedal. Like it grabs a little and then clunk, it grabs like it should. I've also had a problem with 4 wheel drive not always engaging when it should and then it clunks and engages or when its supposed to disengage it also gives a similar clunk. Could there be a more serious problem possibly in the diff?

 

[Landcruisin60]

Figured it out. One of the bolts to the caliper bracket is missing. So when you put the brakes on, the caliper pivoted on the lower bolt and that was the clunk. But when the bolt came out it messed up the threads. So I spent a few hours looking for an M12 1.75 tap with no luck. I was surprised when I found a metric bolt in a domestic truck. So I have to look for one tomorrow so I can put it all back together.

 

[MAKG]

Hehe, I guess you just discovered that there is no such thing as a domestic vehicle (domestic assembly lines, sure, even for Toyota, but purely domestic supply chains went out the window decades ago). In these late models, almost all the bolts are metric.

Isn't M12x1.75 a more-or-less standard metric (coarse thread) tap?

 

[Landcruisin60]

Its kind of a good thing. I bought a bunch of metric tools for working on my Landcruiser and Saab so I have very few SAE sockets.

Yeah when I bought the bolt it said "standard M12 1.75 coarse" so I have a few other places I need to look.