Nickstock98t/a

so my girl's grampa says i got a loose rear end. and that is why i'm hearing a knocking noise from underneath in the back. cant be my u joint, we just replaced it thinking that was the problem. so he fiddled around underneath my car and says i have a loose rear end. and that the knocking isnt gonna do anything and the only way to get rid of this is to replace my entire rear end. what do you guys think? i respect the guy and all and he's really bright with cars but i'm sure getting more info from you guys (fellow LS1 riders) would help even more. thanks guys

further detail on the knocking sound: happens during first acceleration from a stop. speed dependent. happens only for 1-3 seconds.
thanks

Tom's_03SVT

what about your tranny mount?

import_raper

Do you have Lt's, I know your sig says bone stock but people don't ever change them.

Nickstock98t/a

i am bone stock and my tranny mount is fine im guessing. no ones ever mentioned my tranny mount. thats not where the knocking sound is coming from i dont think. thanks

LS1>girlfriend

iTrader: (19)

when does it "knock"?

as for elders that arnt activly into repair work...my grandpa knows a fair amount about cars but he comes up with some pretty weird idea's as to whats wrong.

Nickstock98t/a

when i'm accelerating from a stop. anywhere from 0-35 mph. also when i'm just cruising slowly and i accelerate a little it'll knock. it doesnt happen every time but it happens. sometimes i'll also hear a little thick metal "POP" sound with it.

Nickstock98t/a

ha ha ha. that sounds about right. he's a great guy though. sometimes he's on the money and sometimes he's close. he's got this like 80's Nissan/datsun z that just sits in his garage that he's been working on for a long long long long time. his tools just sit on top of it now.

LS1>girlfriend

iTrader: (19)

your sure its not something else banging or rattling? have you looked over your lower control arms, torque arm and panhard bar? rubber bushing's specifically.

Nickstock98t/a

i don't know, man, this is starting to be too much for me and above my league when it comes to car diagnosing and repairing. i'm just a kid trying to learn as much as i can. this problem has been on going for about 4000 miles/6 months now. i've shown an ls1 so called expert over at firestone and he and my girl's grampa said it was a u-joint problem. so we replaced it and it was still there. my problem sort of sounds like this guys problem over @ https://ls1tech.com/forums/gears-axles/865204-banging-problem-need-advice.html
i'm starting to think i should bring my car to a shop for free diagnosing and maybe an estimate. can you guys recommend a place? or is there anyone here from iowa?
thanks for the help and input though guys. i just think i now really need someone that can physically check her out.

LS1>girlfriend

iTrader: (19)

ya, i would take it in. we cant really be much help without seeing and driving the car. i would take it to a dealership, find out whats wrong, then either find a shop that will do the work or come on here and we can you guide you through it.

Nickstock98t/a

thanks man. will keep you guys informed.

Shinigami2x4

Tell you what - go to autozone, get yourself some ramps. get it on top of them and look under the car - check the tranny mount by trying to lift it or shake it and if it moves alot then its bad or loose. check exhaust piping and all bushings ect. if you still dont know get youself a haynes manual and flip though that to help you out.

RooRnZ28

iTrader: (14)

does it sound like metal banging? it couild be the exhaust pipes hitting the rear end..

GregWS6&z28

iTrader: (8)

im betting on trans mount. take it off. it's easy. it's probably ripped in half

Unstang

iTrader: (26)

It could be a broken trans mount or maybe a loose or broken rear suspension component...

Hard to diagnose something like this over the net.

getusumws6

iTrader: (9)

what area do you live in, your avatar says "midwest"?

Nickstock98t/a

im in north east iowa. thanks

zz4camaro1980

just reach under the rear end and try to rotate/rock the lower control arms, mine were so worn out that I could rock them by hand... replacing them got read of my clunking noise when changing gears.

joshp14

iTrader: (5)

As said above, get under the car and manually move all of the suspension components on the rear...torque arm (bushing at tranny), tranny mount (lay on your back and 'bench-press' the tranny, if it comes up off the crossmember you have a bad mount), lower control arms, panhard bar. Also check exhaust components from front to back and see if its close to any of the floor panels...look for rub marks on components.

Also, good luck finding a shop that does "free diagnosis" unless you know the tech or owner of the shop. I live in West Des Moines and I'm a tech at a chevy dealership...used to live in Waterloo...doesnt help you much though.

Nickstock98t/a

thanks guys. i'll check all you suggested when the sun comes up. will let u know

HEY JOSHP14 you said you use to live here in the 'loo. and your car does look familiar. did you use to drive by hoover middle school/lou henry elementary frequently when you were here? around 2006

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