My truck has been doing this weird thud when I hit the breaks. It doesn't do it all of the time, just every time I hit the breaks hard and just sometimes when I hit the breaks normally. It's the same feel as if you have something in the bed that's hitting the front of the bed when you hit the breaks, except it's right under my feet that I'm feeling it. Anybody know what this could be? Should I be worried aobut something being loose? I tried checking all of the bolts in the suspension and leave springs to make sure they were lose and shifting forward, but everything seemed fine. Please help.

 

If it has leafs then you must have a 4x4. So what I would do that only takes a min to check and happend to me is go out and grab hold of the u-joint in the front right behind the tire and try to move it around. Straight up that kinda thing. It could be that you have a bad hub. I had a bad hub and changed them myself took a couple hours did them both at 100k. There should be no play. What happends is even when your not in 4wheel the mass has weight and it does spin as you go down the road now obviously its not looked in but its spinning. Now if you have done repairs of axles things like that you understand an axle shaft is still probably 35-40lbs or so you get that spinning at however fast your going and then hit the brakes that weight wants to keep going further and if there is play in the hub(bearing shaft rides in) as it is a unitized 4x4 hub the hub is junk and you replace the entire hub. For nice Timkin hubs there a few hundred a hub you can get cheaper but if im going through this much work to change im using good. Its either that or a ball joint issue. I would be on either. Ball joint because when you break again truck wants to keep going if there is play at the ball joint usually bottom since the wieght of the truck sits on it always then it will clunk or pop noise. Hope this helps.. to check ball joint jack up axle so tire is about 2-3 inch off ground and stick your head behind tire and have someone use a big crowbar undertire and lift had to see if there is play at ball joint. Any movement and its junk..



Ryan

 

It's probably front sway arm bushings worn or missing.

 

How do you check for something like that? And I noticed today that it sometimes does it without me feelin it, but I can just here it.

 

Passenger side sway bar


Driver side sway bar - no pretty bushing


Should the driver side look like that? Would this be my problem possibly?

 

Is the passenger sway bar bushing anywhere near the exhaust? Could that metal washer be put in there to act as a heatshield?

 

What is that crack running up and down the frame rail in the picture?

 

Well judging by the two huge bolts a few inches back and the overlapping pieces of metal on the bottom and top of the frame rail, I would say it's just two pieces of metal stacked on top of each other, not a crack...some sort of reinforcement maybe. But don't go by me, I'm just a ME major.

 

I figured out what the problem was everybody. I was up under my truck trying to find a way to get the coolant plugs off the block to drain the coolant (whoever did it last torqued the **** out of them), and I just happened to glance over and saw two bolts sticking through the frame with the nuts unscrewed almost all the way off. I looked around that piece of the chassis to see what they were supposed to be holding, and it was in fact the engine block. I went to the other side to see if the other side was tight, and they were in fact loose also. So I got a torque wrench and threw about 130ft*lbs on there. Haven't been able to make it thud since. So I guess the thud was my entire engine block shifting forward every time I hit the breaks. Kinda scary to think about. I guess when the engine block was replaced about 2 years ago the dumb@sses didn't tighten them back down. At least it wasn't the transmission or I'd probably be sitting at a redlight right now with the gas down sittin in place with the transmission spinning in circles.

 

You are right the other picture clearly show 2 section's of rail sandwiched together.

 

wow! Good find.

 

Absolutely great detective work!

Mike

 

It was probably your tranny keeping the engine in the truck!

 

I was thinking the exact same thing. I checked the tranny bolts too. Who knows what else those morons didn't tighten up. Guess I'll investigate when I hear another strange noise or feel something weird. Guess I better check the turbo first thing tomorrow.