rear end knockin

**whiteLS1TA** · 04-02-2008, 12:18 PM

i was driving my car today and i raced a mustang. i killed it but i noticed when i hit 2nd my rear end kinda made a knock, like it was loose. i took my friend for a ride and he thinks its the tranny mount. this also happens when i do a donut. could it be that i have more tread on my right tire then the left?

**whiteLS1TA** · 04-02-2008, 01:11 PM

thanks for the help guys!

**t-rock** · 04-02-2008, 03:19 PM

explain a little more to us please.

**Y2KPewterSS** · 04-02-2008, 03:45 PM

Sounds to me like your 10 bolt giving out its last few screams of life, in other words, your 10 bolt is fixing to take a crap on you.

**Wesman** · 04-02-2008, 04:27 PM

Does the shifter move up and down when you get on/off the throttle or shift gears?? if so, its probably your trans mount.

Check that first, its easy to spot, right between the trans cross member and the tail shaft of the trans. If its broken or worn, just pick up a poly mount from one of the sponsors

**whiteLS1TA** · 04-03-2008, 02:49 PM

yea it does go up and down. but it has been doing that for a while, the knock is coming right under behind the front seats. i have an extended warrenty i wonder if they would cover my rear end if it is the rear end. i hope not but the only time it does it is when im racing or shifting kinda hard from 1st to 2nd sometimes 3rd too.

**Rhinohuey** · 04-03-2008, 04:05 PM

Originally Posted by whiteLS1TA

yea it does go up and down. but it has been doing that for a while, the knock is coming right under behind the front seats. i have an extended warrenty i wonder if they would cover my rear end if it is the rear end. i hope not but the only time it does it is when im racing or shifting kinda hard from 1st to 2nd sometimes 3rd too.

I've got the EXACT same symptoms as you do. I have been trying to figure out the problem for a few months now. At first I thought it was the clutch (replaced it becuase it slipped anyway), then I thought it was the tranny mount (swapped it out for a poly mount), and now I've decided there is just alot of play in the rear end.

Another time I get a knock is when I have a load on the drivetrain when I'm accelerating (or even if its just slipping the clutch a little with the E-brake on) and then I push the clutch in quick. Also, when I pulsate my gas pedal to make the car buck while I'm moving, I get really bad clunking sounds everytime it bucks.

**whiteLS1TA** · 04-03-2008, 04:08 PM

Originally Posted by Rhinohuey

I've got the EXACT same symptoms as you do. I have been trying to figure out the problem for a few months now. At first I thought it was the clutch (replaced it becuase it slipped anyway), then I thought it was the tranny mount (swapped it out for a poly mount), and now I've decided there is just alot of play in the rear end.

Another time I get a knock is when I have a load on the drivetrain when I'm accelerating (or even if its just slipping the clutch a little with the E-brake on) and then I push the clutch in quick. Also, when I pulsate my gas pedal to make the car buck while I'm moving, I get really bad clunking sounds everytime it bucks.

thats exactly whats going on with my car.

**Hot Black Trans-Am** · 04-03-2008, 04:09 PM

Torque arm mount?

**Hot Black Trans-Am** · 04-03-2008, 04:11 PM

Could be a bad motor mount too.

**Rhinohuey** · 04-03-2008, 10:52 PM

Originally Posted by Hot Black Trans-Am

Torque arm mount?

Thats another good thing to check.

I've looked my ta mount over really good and it doesn't seem to be broken or anything, but I'm not sure...I'll probably go ahead and replace mine with a poly mount.

**LETHALxLS1** · 04-03-2008, 11:02 PM

I know on my old Z when I got the rpms up to where it needed shifted fron 2nd to 3rd and instead of shifting I just let off the gas completely it would bang and that was the torq arm bolts had come loose.

**whiteLS1TA** · 04-04-2008, 09:00 PM

i found a shop out here where they specialize in fbodies and ls based engines. i have and appt for them to take a look at my TA and try to find anything worng with it. so hopefully i get some good news.