lexvortex

Hi guys,

I just had the outer front CV boot replaced on my car, which I tore during an autocross event somewhat recently. It was done with the the help of a mechanic friend. Everything seemed to go fine until I went for the test drive and heard a slight knocking sound coming from the driveshaft that was not there before. We analyzed the install but couldn't find any problems so we took it apart and put it back together again to double check the assembly but the issue still persisted. The joint articulates fine and the parts seem to be in good condition. The only thing that we got wrong is the driveshaft nut torque, somehow we got 165ftlb as the necessary torque value instead of the 360ftlb. I am going to go there tomorrow to torque the nut to correct value. Do you guys think the incorrect torque could have caused the issue or could it be something else? Any ideas of what to look for while I'm there? I'd appreciate any help.

Cheers,
Dave

Macster

Properly torque the shaft nut and road test the car. You'll know soon enough if the incorrectly torqued nut was the problem.

charlieaf92

When do you hear the knock? Is it all the time / starting from a stop / going over bumps / turning / etc?

lexvortex

Thanks for the replies. The knock is constant regardless of turning or bumps and gets louder as i go faster.

charlieaf92

Hm. In order to replace the outer boot, you had to remove the inner CV joint completely, right? How confident are you that you reassembled it correctly?

lexvortex

We followed the video you posted and rebuilt it twice. I am confident we assembled it correctly. There is only one way it will go together and be able to articulate freely. I just got back from the garage after trying to torque the nut to the proper 340ftlb and it made no difference. I can also see the shaft has a slight wobble to it as if its not centered correctly. I don't know what would cause it to wobble, it is held in place by two splined shafts on either end. The only thing it could be is if the inner CV spline was bolted on to the axle incorrectly, maybe not flush such that it isn't concentric with the outer cage of the bearing.
Could it be that the inner CV joint is worn out and by taking it apart and not putting it back together exactly as before, the small variations in wear on each part would add up to make it off center? I find that hard to believe, the parts had no obvious wear on them. Maybe it the wheel bearing? But it's not a grinding sound, only a clunking sound.

charlieaf92

Wow that sucks. It sounds like you’ve been pretty meticulous. Have you lifted the front wheel and turned it by hand to try to pinpoint wher the clunk is coming from? The wobble in the axle doesn’t sound right. Is the inside seated in the differential correctly?

lexvortex

Hi Charlie, thanks for the ideas. As far as we can tell, the axle is seated within the diff correctly, it's seated right up against the seal. We had the car up on the lift and started it up with the wheel off so we could figure out where the sound was coming from but could not isolate where it was coming from and it really only becomes noticeable above 30km/hr. Not sure if turning it by hand would cause the knocking noise but it would be worth a try when I go there next.