LS1GTO Forums banner

1 - 20 of 22 Posts

·
They call me the crapple
Joined
·
912 Posts
Discussion Starter #1
Heavy deep groaning sound and nasty vibration from the rear end of the car when decelerating and maintaining speed above 60+ MPH. Clutch in and in neutral same issue. Whole car shakes. Not a bent rim or out of balance tire. Brakes and rotors are still good. New single piece Hinson Motorsports driveshaft with no issues. Installed 3 weeks ago.

rear pinion bearing? Other differential issue? Driveshaft issue?

This is a daily driver and this thing is driving me crazy and I can't seem to figure it out. Any help appreciated.
 

·
Worthless reject member
Joined
·
40,745 Posts
could be a very bad wheel bearing, could be cv joints, could be driveshaft.

if it's only on deceleration, perhaps the pinion is so loose it's about to fall off?
 

·
Registered
Joined
·
1,313 Posts
What condition are your tires in? I recently replaced my warn out 18" M/T drag radials for some potenza RE760's and all rear end vibration is gone. I did not realize the tape weights had gone missing until the wheels came off. I was experiencing hella shaking, from the rear at any speed above 70 mph.
Irregardless get her in the air and start looking for abnormalities before you take it to a shop. Manually rotate the rear tires and see what the axels and driveshaft are doing.
 

·
Registered
Joined
·
1,186 Posts
Had this issue except came in over 80 if cruising. Would disappear under heavy acceleration or engine braking.

Turned out my stubs where twisted up pretty bad. New stubs and no more vibration.
 

·
It's simple physics
Joined
·
3,733 Posts
All of the above.

Plus, no pedestrians or shopping carts or bicycles stuck under rear of vehicle right?

LR
 

·
Registered
Joined
·
66 Posts
Heavy deep groaning sound and nasty vibration from the rear end of the car when decelerating and maintaining speed above 60+ MPH.
I'm having the same issue. Went coilovers, poly, and sticky tires and now it vibrates. Even at low speeds. Checked DS and CV's no issue. I'm leaning towards axle stub now after reading Scuba's comment.. Could be the same for yours.
 

·
They call me the crapple
Joined
·
912 Posts
Discussion Starter #7
I'll have to check the stubs it sounds like. I don't think its my CVs.

Anyone have a grenade I can strap to this damn thing and let it go boom?
 

·
Registered
2006 Pontiac GTO
Joined
·
388 Posts
I have been dealing with similar rear end vibrations that start at 90+ mph. For me the vibrations are worst in neutral and decrease when I am on the throttle in gear. I just replaced my tires and road force balanced them yesterday and still felt some vibrations (although it seemed less) on the way to work this morning.

How could the CV's cause vibration? I have noticed that my CV's (GForce level 1 anti-wheelhop) have a significant amount of free play when I turn the rear wheels by hand. Could that be the problem?
 

·
9 Second Club
Joined
·
860 Posts

·
Registered
Joined
·
1,186 Posts
I have been dealing with similar rear end vibrations that start at 90+ mph. For me the vibrations are worst in neutral and decrease when I am on the throttle in gear. I just replaced my tires and road force balanced them yesterday and still felt some vibrations (although it seemed less) on the way to work this morning.

How could the CV's cause vibration? I have noticed that my CV's (GForce level 1 anti-wheelhop) have a significant amount of free play when I turn the rear wheels by hand. Could that be the problem?
This is how mine started.. I have gforce axles as well too. Check stubs
 

·
Registered
2006 Pontiac GTO
Joined
·
388 Posts
This is how mine started.. I have gforce axles as well too. Check stubs
My stubs are stock and I have never gone into the differential before. What more precisely should I look for in the stubs? In and out and/or up and down free play?.. being bent somehow?

Edit: I just saw your earlier post about them being twisted. Can you see this without getting into the differential?
 

·
Show Car
Joined
·
9,523 Posts
My stubs are stock and I have never gone into the differential before. What more precisely should I look for in the stubs? In and out and/or up and down free play?.. being bent somehow?

Edit: I just saw your earlier post about them being twisted. Can you see this without getting into the differential?
The stubs will have to be removed from the diff to check them. They are easy to get out, just remove the half shafts from them and then they will just pop out with a pry bar and a little prying. You will be looking at the splines for the twisting, as this is the area where they normally twist.
 

·
Registered
Joined
·
1,186 Posts
These were my stockers. This is actually the better one
 

Attachments

·
Registered
2006 Pontiac GTO
Joined
·
388 Posts
The stubs will have to be removed from the diff to check them. They are easy to get out, just remove the half shafts from them and then they will just pop out with a pry bar and a little prying. You will be looking at the splines for the twisting, as this is the area where they normally twist.
Well that sounds easy enough.. please excuse my next question which may sound dumb but should I drain the diff before I remove them or the fluid will not spill out?

Scuba, those really are pretty twisted. My engine is also bone stock though. Do you have any serious power adders?
 

·
Registered
Joined
·
1,186 Posts
No you shouldn't have anything spill out if the car is on relitively level ground. And yeah my makes good power, it's the wheel hop that does this though and I've heard of it happening at stock power levels. It doesn't take much to tweak them IMO
 

·
Registered
2006 Pontiac GTO
Joined
·
388 Posts
Oh well in that case I am betting this is my problem as well. I have experinced serious wheelhop even with the anti-wheelhop axles so I would not be surprised to see this at all.
 

·
Transplanted Sooner...
Joined
·
591 Posts
Since having my rear wheel bearing replaced, the bearing nut on both sides has came loose twice. First time it destroyed the new bearing because I let it go too long (other drivetrain vibrations to be addressed...diff, bad u-joints on driveshaft, CV's needing a rebuild, etc).

Got the car back from all of the drivetrain upgrades and rode smooth as glass for a month, then one day started vibrating again. Took it back to the shop who found the bearing nut had loosened again, so they applied loctite and re-torqued to spec.
 

·
The Entenmann's Shim-Sham
Joined
·
12,143 Posts
I was going to say that usually wheel bearings will growl if they are too far gone.

I would check the stubs and then the wheel bearings.
 

·
Registered
Joined
·
1 Posts
Heavy deep groaning sound and nasty vibration from the rear end of the car when decelerating and maintaining speed above 60+ MPH. Clutch in and in neutral same issue. Whole car shakes. Not a bent rim or out of balance tire. Brakes and rotors are still good. New single piece Hinson Motorsports driveshaft with no issues. Installed 3 weeks ago.

rear pinion bearing? Other differential issue? Driveshaft issue?

This is a daily driver and this thing is driving me crazy and I can't seem to figure it out. Any help appreciated.
What
Heavy deep groaning sound and nasty vibration from the rear end of the car when decelerating and maintaining speed above 60+ MPH. Clutch in and in neutral same issue. Whole car shakes. Not a bent rim or out of balance tire. Brakes and rotors are still good. New single piece Hinson Motorsports driveshaft with no issues. Installed 3 weeks ago.

rear pinion bearing? Other differential issue? Driveshaft issue?

This is a daily driver and this thing is driving me crazy and I can't seem to figure it out. Any help appreciated.
Have you found out whats causing it because im having the same problem and i have no clue what it is
 

·
Administrator
Joined
·
9,483 Posts
This member has not been on the forum in almost two years, don't expect an answer.
 
1 - 20 of 22 Posts
Top