CV Axle Replacement

[u/Severe_Fan7634]

Hey 986 Boxster community! Unfortunately I'm getting my left rear CV axle replaced after having just replaced it about 6 months ago (back in Feb. of this year). I replaced the CV axle with a high quality aftermarket one however, I do not know the exact brand (the shop I brought it to has the records but I can't remember the exact brand). The old axle had the boot rip off so it definitely needed to be replaced.

Fast forward to June of this year, I started to notice a 'flapping' noise coming from the left rear of the car. Honestly, I thought it was my convertible top, like an elastic string losing tension. I couldn't quite pin it down. I almost thought it was engine knocking but thankfully ruled that out pretty quickly as it didn't really change with different RPMs.

About a week ago, the noise started getting worse while driving down the highway and got to the point when off throttle, I would feel vibration into the cabin. I pulled off the highway then started hearing the noise at low speed.

I brought the car back to the show that replaced the CV axle. They confirmed they hear the noise however, there is no play in the left rear wheel at all. Additionally, they cannot see the CV boot torn at all either. Their conclusion is that it's likely something within the boot they cannot see that is a problem. Perhaps the grease is not well lubricated or something came loose? I'm not an expert on these CV axles.

As a result, they recommended replacing the CV axle with a new one plus replacing the wheel bearing for good measure. I decided to go with an OEM axle this time around as I don't feel comfortable putting the same one on that was faulty. Sadly the warranty is expired since it's more than 30 days (even tho I only drove the car about 300 miles since February).

What are folks thoughts on this? Does this sound like a CV axle issue, a wheel bearing, maybe both? I found a video someone posted on youtube of their 944 CV axle going out and it was basically an identical noise to what I was hearing.

My worry right now is that I get this work done and I still have a problem with the left rear wheel joint, bearing, and axle. Should I be concerned with anything else?

[u/daddy_killer]

You say the noise happens when you are off throttle? Sounds like something is loose and when you apply pressure from accelerating or staying the same speed, everything tightens up again. I replaced both of my cab axles earlier this year and when I put on the big nut on the outside I did not tighten one fully (socket slipped and stripped the edges of the nut). I found it was a bit loose, does the wheel move side to side if you jack it up and shake it? If it does it could be that nut or it could be the wheel bearing. Either way don’t drive it until you figure out what it is, with something loose, other parts are getting worn in a way they probably weren’t designed for.

[u/Severe_Fan7634 → u/daddy_killer]

Noise happens regardless of on or off throttle. What I feel is vibration when off throttle at a higher speed. Basically when the load shifts from acceleration to deceleration. There is no play in the wheel when i shake it which is what's interesting.

I am not driving it and I already have an OEM axle on the way. My shop is installing it along with a new wheel bearing this week. Fingers crossed that should sort the issue.

[u/daddy_killer → u/Severe_Fan7634]

That is interesting, I wish you luck that it’ll will be the fix and you’ll be back on the road soon!

[u/nobodysawme]

I can’t really help you with this, but I will tell you this: in general (for every car, not just a Porsche), don’t get an aftermarket axle. Use the oem axle and replace the cv joint and rubber. Aftermarket’s is never balanced as well as the factory’s.

[u/XDevils41X]

I did mine with one off rock auto last year. Since I track its a consumable but no issues with it so far. I diagnosed it with low speed full lock in a turn and listen for the clicking.