Knocking from the front end under load?

[Mark sP]

Hi guys.

My next problem for your consideration and expert knowledge is a knock knock knock noise from what feels/sounds like the RHF corner.

It only happens when turning and is louder when turning hard at a fair speed. I can feel it through the floor. The Knocking speeds up and gets louder as the car gets faster. In a straight line, it goes away.

The story goes like this, (and I refuse to take it back to the wrench a third time, I will try with your help to fix it myself)

I took the car in for replacement front wheel bearings. I knew one was out because it rumbled at all speeds. I thought it best to replace both sides. The wrench tells me the brake rotors are badly worn, so I said fit the bearings and I'll bring the car back for pads and discs.

I picked up the car and noticed the knocking straight away. I went back and he reported that the knock was nothing to worry about, and was caused by him having to hammer the disc on the right side to free it. No biggy then I thought.

I took the car back with new pads and discs for him to fit. After getting the car back, the knock is just as bad. And as I said above, I am not going to take it back.

Any ideas as to where I should look? Could the new bearing have been faulty/damaged when installed? It almost feels like a loose wheel, but it isn't. What could cause this sort of knocking that can be felt and heard above the engine and the stereo?

Your help is much appreciated. (Sorry for the long post)

Mark

[911mot]

Sounds like a wheel bearing to me.
If its the RHF outer it will get noisier as you turn left and load it up. If it's the RHF inner it will be noisier as you corner right.
Outer are easy to check. Look for discoloration of the needle rollers in the cage.

[911mot]

Are you getting any brake judder?

[Mark sP]

Hi mot. Thanks for the reply.

It is louder turning left, much louder. Brakes are great. Stops good and straight.

New tool kit arrives on Monday At least I have something to use it on!!! LOL

[Zeke]

You might check the CVs. Even though the noise is in the front (or it seems to be), it can originate in the rear. When you turn, the CV is in a different angle due to body roll and if there is something wrong, it could manifest itself as the noise you describe.

Just a thought.

[Mark sP]

Thanks Milt.

How do you check the CV joints?

[911mot]

Ok you need to inspect the RHF outer bearing race.
Remove rhf wheel - pop off dust cap in centre of hub.
Undo allen keyed locking nut, remove washer and pop out the center of the bearing.
Give it a good clean and look closely at the needle rollers look for discolouration. Brownish would mean bad/old grease or water ingress, blue would mean overheating due to lack of grease. It is also possible the mech who fitted the brg could have slipped with a chisel as he was putting the outer race in and scored it slightly, so you need to get a rag and get all that nasty old grease out so you can inspect it. Repack with new grease before reassembly.

To check the inner bearings is a bit more complex because you need to remove the caliper and disc to get at it.
good luck, keep us posted and dont forget the pics!

[Mark sP]

Thanks guys.

It will be 10 days or so before I get chance to have a look. I will report back and hopefully have pics too.

Mark

[FrdzRed]

Just a thought, but I had a knocking sound when turning and it ended up being a bushing that had worked itself loose from the steering rack.

[Mark sP]

Something else to look into. Thanks for that.

[randywebb]

Do a Quick Survey first -- jack up the front and grab each wheel 6 & 12 o'clock and push & pull; same at 3 & 9 -- see if there is any play.

Get under and grab the CV joint half shafts and try to pull push & rotate them - check for play; same for each bolt -- 4 sets of those - 2 at each R wheel & 2 at each mount on the trans.

IF you don't find anything with this 15 minute test, then do the more involved sleuthing above.