Annoying knocking noise

[LukeC981]

Hey guys,

I've had a look through several posts but none have really answered what I've been hearing in my car.

Under acceleration at low speeds, there's no knocking noise, as soon as I let off, the knocking starts. However, if I keep accelerating past, say 15mph, to 60/70mph, the knocking noise increases in proportion to the speed, making me think it's definitely a wheel bearing.

I thought it was a part of the arch liner flapping as I increased in speed, however, it's secure all the way around. With previous experience of wheel bearings that have gone, they have never just gone to a knocking sound, they've always whined.

I've had the wheels off on both sides and I can't feel any play any where, apart from on the drive shaft (behind the CV boot) on the drivers side. I can move it about 3mm towards the hub and away from the hub.

Is this further evidence that the wheel bearing has gone? I've sourced some new ones on eBay going cheaply.

 

[SootySport]

No, that's not a wheel bearing noise, w/b whine and groan when turning corners. CV or drive shaft, yes it could be, they should slide in and out a bit but not twist either way. Check the engine mountings, exhaust and anything else bolted to the body.

 

[LukeC981]

Me and my mate had it up on the ramps in work last night and fixed it. One of the calliper bolts was slightly loose and we noticed that there wasn't a locater screw on the disc. The disc had actually popped off of the hub ever so slightly. I've taken all of the calliper bolts out and put a slight bead of loctite on them and tightened them. I've also fitted a located screw into the disc and the noise has gone. So happy it wasn't anything serious.

Thanks for your reply though

 

[SootySport]

Excellent, easy fix then. I would say a loose calliper bolt is serious, Loctite for anything like this is a must.

 

[LukeC981]

Yeah definitely. It was one of the long silver bolts in the centre of the calliper with the smaller sized torx head.

I took the opposite side bolts out and put loctite on those too just to be safe.

We did notice one major issue (my friend owned the Audi before I swapped it with him) that he had made. He bought rs4 reps for it before I got it, however, he kept the standard wheel bolts and they only look like they're biting on 4 maybe 5 threads. The standard bolts are 28mm thread length and the next M14x1.5 ball seat bolts I can find are 35mm thread length. Would they fit into the hub and hold the wheel tight or are they too long?

 

[SootySport]

Oh my god , that's not good. Buy the longer bolts and fit the wheel, then turn the wheel by hand and see if the bolts catch anything around the hub. You can always grind a bit off if too long and smooth off the tip so they screw in easily.