Heard a POP or Thunk when she Hooked

[svtpolice]

Hey guys,

I hadn't taken the car out in a while. Last night I took a buddy of mine for a quick ride to show him the car. I rolled first nice and slow, then heated the tires up a little with a light double clutch and when she hooked I heard a loud POP or light Thunk in the back, passenger side . I kept on it and she didn't feel any different. I even tried to replicate the issue and it didn't do it again.

Any thoughts on what it might have been? Could the suspension have shifted and settled into a spot or something? The road was flat and smooth so I don't think it was the road. Has anyone heard this before?

 

[Catmonkey]

Hard to say, but I'd be under it looking for what i might be. Something broke or moved. I can think of several possibilities. Which BMR upper and lower are you running?

 

[svtpolice]

Hey Catmonkey,

The standard poly non adjustable lowers and the adjustable poly upper.

 

[gimmie11s]

Suspension shifted... my 2014 would do this every once in a while.

It was usually the axle settling its position (side to side movement) under hard acceleration with the fraction of an inch play that existed between the bolt sleeve and the bolt itself at either end of the panhard bar.

.

 

[Catmonkey]

I'd make a visual inspection of the bushings, just to make sure none broke. I might also check the torque on all those fasteners on the rear end. Beyond that, if was an axle, I think that would already be apparent.

 

[TK1299]

It was the road surface being ripped apart.

 

[RedVenom48]

+2 on checking your bushings in the back. I blew out a few lower control arm and 1 upper poly BMR bushings. Everytime it was during a run down the track.. so yeah, not fun. Lol

Its the flutes they mold in for grease. A majority of bushing failures start there and spread through the bushing. Then one final violent hit cracks it wide open and boom, you hear a noise.

For any kind of abusive driving, id highly recommend switching to rod end bearings

 

[PistolWhip]

Coulda hit the bump stops, my car did that on a hard hook before I cut the top off of them, but like Cat said; don't take any chances and make sure you check on everything.

 

[JB_2010GT500]

I second the bump stop theory. I lowered the rear of the car about 3/4" or so and was hitting the factory bump stops. Replaced them with the softer ford racing version and cut them down to about half the height.

 

[SCGallo2]

+1 for suspension shifted. I had the original BMR 2-hole design LCA relo brackets and panhard rod relo bracket installed on my car back in the day, and on a hard drag strip launch I would hear a loud bang from the rearend. I lifted the first time it happened and everything felt normal so I got back in it; happened a few more times after that. When I removed the LCA relo brackets, I could see rub marks on the paint from the brackets shifting. I believe they resolved this issue with the newer 3-hole design since I haven't heard of any issues since the revision. I went with Maximum Motorsports bolt-on LCA relo brackets and removed the panhard rod relo bracket since it was no longer needed for my application, and I haven't had any issues since. As others have stated, check all of your bushings and re-torque everything.

 

[69b302]

I would suspect the panhard bar. Ford did beef up the bolt size and body mount on the later years. It is a problem and will get worse if you do not fix(oval out hole).

 

[SirShaun]

It was the axle tube shifting the tiniest bit. If your on a sticky enough tire like a DR, it will put the tire right into the quarter panel. Weld your axle tubes. I heard it once or twice bull shitting on the street, then it twisted right into the quarter panel at the track, dry hooking.

 

[RedVenom48]

Swarr or CHE bar should be your next step