What could it be?

I've got something knocking in what sounds like the right rear. I thought at first that the right rear rotor was warped because of the intermittent sound it makes but after replacing all four rotors and pads I've still got the knocking noise coming from somewhere back there. I'm leaning towards it being the hub because, unbeknownst to be prior to buying, the car had been wrecked. P/O was pinched between a semi and a K-rail but he failed to mention that, I only found out after browsing the mazdaspeed forum that it had done a number on the right front/rear suspension. Anyway, I've tried taking a few videos to capture the sound but I don't know if it will help. If I turn right, thus taking some of the load off the RR, it will go quiet but as soon as it is back under a normal load it picks back up. I've also noticed that there is what I think is too much lateral(back and fourth) slack in that hub when we had the wheel off but I've yet to compare it to Rotarynerdette's car to know if it's excessive. Do any of you guys and girls know of specific points that I need to check to try and narrow down the culprit or have an idea as to what up?


The video quality isn't great but you can hear what I'm talking about.
At around 25 seconds in I start making little right turns and you can hear the knocking stop and start.
http://i173.photobucket.com/albums/w...h_DSCN0662.jpg


Only vid I could upload to photobucket, the other two are just over their 100MB limit.

I would think it's the hub/bearing assembly. Not quite sure what you meant by lateral slack in the hub with the wheel off but there shouldn't be any slop in the wheel and if there is the only thing I can think of that could cause that in the rear is the hub/bearing.

It's much more fun in the front, I have some slop in one of my fronts and I had to start from the hub and work my way in to the outer tie rod end to determine that it is in fact the inner tie rod end.

+1 bearing

Creek's pdf shows maximum bearing play of .002" (.05mm).

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Originally Posted by creek

+1 bearing

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Awesome Creek, thanks. I assume this is the same for 04 MSM'?

Quote:

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Originally Posted by POS Racing

Creek's pdf shows maximum bearing play of .002" (.05mm).

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Haha, it was definitely more than that. Goin' to order a new bearing tomorrow, doubt any of the local part stores have it in stock but we'll see.

Most of the parts stores list the part on their website but don't show it in the store. You may have to order it or try the dealer.

A fairly quick way to find out if it is the bearing is to remove the cotter key and locking cover and see if you can turn the BIG bolt on the end of the hub. If the bearing is gone, you'll be able to turn it easily. If not, it's torqued to about 150lb/ft. If it's bad, you will need to remove the entire assembly and put it in a press to remove the old pieces and install the new one. IIRC, the bearing is about $90. Good luck!

Little update on my situation.

Turns out the bearing was fried and took the hub with it. Merv, the we were able to get the 'big bolt' off the end with a pair of pliers lol. Bearing was only 24 bucks from Autozone, :) Got a new bearing in and still waiting on my new hub but it should be here come Wednessday. I'll take some pics of the hub when we get it all back together, it's pretty amazing how much it chewed out of it.