some thing weird is going on in the rear

ever since i lowered the truck, there has been a weird knock in the rear every time i shift or suddenly let off the gas. this doesn't happen if i shift really slowand smooth, only normaly. and for some reason i started to notice it a lot more when i got my bigger wheels.

i kinda know whats going on but i'm not sure exactly. something is lose cuz my dad watched the truck while i accelerate and he said that the wheel moves forward when i do. and when i suddenly let go of the gas on the freeway at like 75 mph, the wheel does the same thing and makes the truck swerve like crazy cuz the rear wheels aren't straight for a bit when i do that.

so i'm trying to figure out whats loose. the u bolts are good. i checked them and they have lock-tight crap on them. could it be the bushings for the leaf springs or something? they seem good when i move the wheel back and forth but i might not be pushing hard enough.

has anyone else had a problem like this or knows what might be wrong and what i should check?

actually this might have been happening before i lowered it. i never really listened to the rear but after i lowered it i was listening closely to see if i can hear anything wrong. but i dont know, it could have started after i lowered it

are your u bolts tight enough your rearend could be shifting

Also your lowering block could have cracked around the leaf pack center pin causing your axle to shift front to back. I would stop driving it right away till you get it fixed.

well i can't stop driving it but i only drive it like 40 miles a day max right now. but it started right away, could the lowering block have cracked right away?

and if this helps, i think that the ubolts were a little too big. they were 3" and the axel seemed a little smaller so i had to bend them in a little to fit in the holes. but i dont think that should matter...

Lowering blocks are quirky sometimes. Look under the truck and make sure the block is on that center pin in the leaf spring. It is easy to put the block in and not get the pin in the hole in the block. If it is not , the block and axel will slide back and forth. This can also happen if the block is defective or the center pin is gone or broken. Also, check that the u-bolts are tight with a wrench. They my look tight, but the back and forth motion of an axel puts alot of stress on them and they may have worked loose. This also may be worn out leaf spring bushings, but that is unlikely if you didn't notice this before you lowered it.

also as i had stated before in one of your other threads. make sure the u-bolt nuts arent running out of threads on the u-bolts. it will seem like it is tight because it gets hard to turn but its not really. you may have to add a spacers or more washers on the nut.

no i didn't run out of thread. i can see it on the other side.

but i might have not gottend the pin in the right place. i had trouble getting the pin in on both wheels but the one that moves i did second so it was even harder. i remember getting really pissed off cuz i couldn't push the axel forward enough. but i was positive i got it in. i'll have to take the wheel off and take a look.

no i didn't run out of thread. i can see it on the other side.

but i might have not gottend the pin in the right place. i had trouble getting the pin in on both wheels but the one that moves i did second so it was even harder. i remember getting really pissed off cuz i couldn't push the axel forward enough. but i was positive i got it in. i'll have to take the wheel off and take a look.

i had a similar problem when ever id give gas the rear end would go sideways and the rear would make cracking noise i thought it would have been my universal joint or something and i seen that one of my blocks were missing lol preetty dangerous i was driving like that for a week or so without knowing.. make sure u get that checked out n fixed