03 986 with Tip - Listen to This STRANGE Drive Train Noise

[r00ster]

Greetings fellow Boxster Owners! I'm more of a lurker here than a poster but I NEED YOUR HELP and so I'm posting this thread!

The Issue:
I'm getting an odd sounding noise from the right rear of my 2003 986 2.7L w/ Tip Trans (US Car) with about 165k miles on the odometer. The sound seems linked to the speed of the car's wheel and is completely independent of both the engine's speed and auto transmission's gear. It becomes audible to me at around 10-15mph and goes away (most likely the wind noise is too loud) at around 50mph. When the car is at rest with the engine on - the sound is not there. The sound only appears when the vehicle is in motion (it's even there when I coast in Neutral or drive in 2nd, 3rd, 4th, or 5th gear). The speed of the noise increases with the speed of the car. The below video was shot with the car moving at around 15-20mph.

https://youtu.be/7Tn2U3KzVv4

What I've Tried So Far:
It's been about a year since I checked the diff. fluid level (dealership maint. records show the diff fluid being changed about 66k miles ago) and yesterday I looked for leaks. Couldn't get a good angle to break the diff plug loose. Will do this if I end up having to drop the exhaust. It was hard to see the bottom of the diff cover (aluminum trans protection plate was a little in the way) but all appears dry (no puddles/leaks/drips in garage). About 25,000 miles ago I replaced all transaxle boots and repacked all four CV joints with LubroMoly CV Joint grease. I did a lot of research before tackling that job. Felt like I used enough grease when I repacked them. The boots still look clean; no cracks and no grease getting flung around anywhere. Jacked up the rear end and searched for play in the wheel bearings by trying to "steer" the wheel left and right (toe in and toe out). Also tried to check the wheel bearings by spinning wheel with one hand and grabbing on to the suspension spring - feeling for any rumble. It sounded/felt ok to me with no slop noted there. I did notice some play in the differential but that's not really a new discovery. It's always had a little slack. It seems ok (no noises/issues) and it doesn't seem like it's been anything getting progressively worse. I’d guess there is about maybe 10 degrees of play when I spin the wheel so maybe at the edge of the brake rotor I could turn it about .5” before the differential would engage the other transaxle... Anyway, last but not least, I also drove the Box with the spare tire on to eliminate the possibility of it being my tire causing the issue.

The Plea for Help:
Anyone hear this noise before? If so, what ended up being the issue? Any other "simple" tests I can do before I start dropping the exhaust and pulling the axles out again?

Thank you in advance!

[Luccia at Pelican Parts]

That is a strange noise. When you tested the bearing - how old are you current ones and have they ever been replaced? I've had bearings cause some seriously strange noises and symptoms before. Sometimes noises/symptoms that didn't make me think it was a bearing. Curious, when you are traveling at the speed in the video and the noise is emitting, did you try to turn and put load on the left or right wheel to see if the noise changes or stopped?

[Boxtaboy]

Did the noise appear after you repacked the CV joints, or just happen recently? Did you check if there were any pebbles or other road debris caught in the brake rotor shields?

[thstone]

Ok, its hard to hear, but if I had to guess, it sounds to me like the brake rotor is rubbing against the brake dust shield (or pebbles are stuck in between). My car will do this occasionally and it won't do it when the car is jacked up, only when its on the wheels and rolling. I removed the dust shields but you can just bend them back out of the way if this is the source of the sound.

Get a friend and find a local hill (just a slight decline) and let the car roll down the hill with the engine off and trans in neutral while someone walks next to the rear wheel to listen. Keep doing this several times until you find the cause.

[r00ster]

Luccia, I did do some turns. My neighborhood has a clubhouse with a small circle drive in front of it - almost like a small roundabout. I drove around and around it. First with a constant left turn then did it with a constant right turn. No change to the noise. I could hear it regardless of the direction I was turning... When driving normally in a straight line and I make a right hand turn (the side where the noise appears to be coming from) the sound "slows down" a little (the frequency of the squeak/squeal slows a little) I think it's because it's the inboard wheel and so it slows down in the turn as the outboard wheel speeds up. The sound does not disappear in a turn. The wheel bearings are original, as far as my maint. paperwork shows so 160k miles on them. I took the tire off and stuck my head in the wheel well with the car in drive and the noise seemed to be coming from in towards the inner cv and differential.

Boxtaboy, the noise appeared recently. In the last week or 300 miles or so. I repacked the joints about 26,000 miles ago. I will check the brake rotor shields as I mentioned above to Luccia, I've stuck my head in between the bearing carrier and the transmission and the sound seems to be coming from the trans side (left ear) and not the bearing carrier or brake rotor area (right ear). Granted a lot of noises going on and not totally sure but pretty sure.

thstone, as you've probably guessed by now, it makes the noise on jack stands and the car in Drive.

Thank you for your input/questions. I'm currently in work on this: car's on stands; passenger wheel is off; the 2 side braces are out; the Trans protection plate is removed; the sway bar is out; the passenger exhaust is pulled (or I should say the section with the 2nd cat. convert.); and the passenger transaxle is dropped away from the drive flange. Moving the inner CV joint and it sounds ok to me. Not sure what I'm listening for but it pretty much makes no noises and moves freely.

[stateofidleness]

odd timing, but my boxster has now become my daily driver and I've had this exact same issue for a LONG time on my '00 base TIP. Mine sounds more like it comes from the driver's rear though. Kudos for actually getting a video of this!

Like yours, mine only does it when in motion, and it starts to become audible inside the cabin around 10mph or so. Harder to hear at higher speeds due to engine/road noise, but stop lights/signs are embarrasing!

I have original wheel bearings and just hit 101,000 miles. My first hunch was wheel bearing, but every other vehicle i've had bearing issues with, it's more of a "howl" or a deep, "growly" type sound. This is more of a "rotational squeaky" sound. Brand new tires all the way around on mine, so not a tire issue.

Subscribing!

[Luccia at Pelican Parts]

Hm, 160k on original wheel bearings is a lot. On a different vehicle of mine I got away with 187k on some of my bearings and they definitely showed weird signs that it was time - not the typical howl noise. I wasn't getting any of the apparent bearing issues that they usually present. I even ran into pad knock-back as they got really bad. You said it's on jack stands - you're putting it into drive and listening under the vehicle? Can you nab a video of what you're doing when there is no load on the vehicle? Otherwise, pretty weird situation here and be sure to report back and let us know once you find out more info.

[r00ster]

stateofidleness: Yes, I hear ya on the embarrassment! I find I'm now "creeping" through my neighborhood at 10mph or less so as to not attract attention and there's nothing I can do about it at stop signs and stop lights. Hopefully, I'll figure this out here and everyone will be able to use this thread if they run across the same issue in the future.

Luccia: I agree the bearings are old but I've run out of "tests" to figure out if it's the bearings. Please share if you or anyone has any other test I can do. I'd hate to start throwing parts at it but I may be getting close to doing that. I apologize if I'm repeating myself but here's what I've done to see if it's the bearings: Grabbing the rear wheel at 3 and 9 o'clock and checking for play; grabbing at 12 and 6 o'clock checking for play; rolling the wheel while grasping the suspension spring and feeling for vibration and meanwhile listening to the bearings trying to hear anything rough going on; finally, with the wheel removed, i stuck my head in the aft portion of wheel well while the was in vehicle's in Drive (don't do this at home kids!) and listening for the sound. The squealing sound seems to be coming from my left ear (towards Trans and inner CV) and not from my right ear (outer CV, wheel bearing, brake rotors).

An Update Since my Last post: I took the car down off the jack stands today. To my dismay, that annoying sound is still there. It didn't reappear immediately, and for about 3-5 minutes I thought I'd fixed it, but once things heated up (?), it started squealing above 15mph again. This time, I tried another test, I got the car up to about 25 or 30 mph, put it in Neutral, shut the car off, and coasted. The squealing sound continued until I slowed all the way down again.

Anyway, here's what I did when I had it on stands.

I removed the "drive flange". Nothing looked out of order from what little I could see inside the differential. Wish I had a new seal (986-397-015-00), it would have been a perfect time to replace it. The flange spins and turns the inner CV Joint and so part of me wonders if this is what's squealing. If that seal is starting to go (it's not leaking) could it cause the spinning flange to squeal? Anyway the diff started leaking fluid when I removed the flange and so I figured I'd change the diff fluid and do it the "right way" by removing the diff cover. So, I pulled passenger side transmission mount so I could remove the differential cover (it freaking connects to the trans on the damn diff cover). However, couldn't get access to 2 of the 12 diff cover bolts (the two to the right of the fill plug - the crossmember was in the way). So I got lazy and decided against doing a total drain and refill. I replaced the flange and topped off the differential with new 75w90 fluid. Next, I removed the CV cover on the outer CV joint. Joint looked like it had plenty of grease but I added some more and replaced the cover and put the car back together. Before putting the wheel back on and taking it down off the stands, I removed the brake caliper & rotor and then inspected and shot the both the E-brake shoes and the rotor dust cover with brake clean. Nothing looked out of the ordinary to my novice eyes.

I'll probably put the car on jacks again tomorrow and try to shoot & share a video to see if it gives anyone any additional ideas.

[r00ster]

I'm now starting to lean towards either the wheel bearings or the outer CV joint. I put the rear end up in the air and put the car in drive and listened with a mechanic's stethoscope. Nothing out of the ordinary when I touched the diff cover but I could faintly hear the squeal when I touched the bearing carrier. Typically, CV's don't squeal (and I recently repacked them) and usually, bearings don't neither but if one of those two is going to squeal, it's most likely the bearing, right?

[Luccia at Pelican Parts]

If you're stuck, and since they're so old, it might not be a bad idea to replace the bearing. Process of elimination. It's not great to throw parts at an issue without knowing what it is first, but it seems that it may be your next move in all this. Those are all the tests I would have done to confirm a bearing, but then again I too was unsuccessful when doing some tests to determine if my bearings were an issue. I've never heard CV's squeal before as their typical noise is a click. Anyways, posted them below if needed and if you decide to replace them. Let us know what happens!

2003 Porsche Boxster Base Convertible - Axles, Bearings & Differential - Page 5

[r00ster]

UPDATE:

After reading Luccia's post, I thought about it and agreed. So, I ordered a bearing and axle nut from Pelican Parts last week and they arrived here in Florida a day early (WTG Pelican and your shipping partner)! I pulled the wheel carrier out of the Boxster yesterday. Now that it's off the drive axle, I've found that there's (lateral) play between the hub and the carrier that I couldn't detect when it was on the axle. Pretty sure it's the bearing that's causing that awful sound in the YouTube video. It's so weird because that's not your typical bearing sound. Regardless, the bearing needs replaced and so the carrier is in a local machine shop where they're pressing out the old bearing and pressing in the new one. Hope to have everything back together either tonight or tomorrow. Will report back to share whether or not this fixed my issue. Thank you everyone for your input!

[r00ster]

Final Analysis: It was the wheel bearing. Noise is gone. I highly recommend using a mechanic's stethoscope to help diagnose an issue like what I was having. All the other tests I conducted (see earlier in this thread) didn't seem to point towards the bearing but the stethoscope helped me narrow it down to either the outer CV or the wheel bearing. Thank you everyone that contributed and thank you Pelican Parts!

[Luccia at Pelican Parts]

Whoo-hoo! So glad that was the cause, as that is what I was leaning towards. You can't always trust that a bearing will inhibit typical wear sounds/symptoms. That is what I have learned from some very severely worn bearings over the years. Now you can enjoy driving your P car worry free. Enjoy and happy I could help.

[stateofidleness]

Thanks for closing the loop on this one! Guess I'll bite the bullet and get mine changed out too.

Did you buy the Hub extractor kit ($379) from Pelican as well, or did you use something else? Thinking of pulling the trigger on the kit to ensure I can do the job easily without issue (only car and daily driver so can't afford any "snags").

Anything else you recommend getting while "in there" - I was thinking: axle nut, a new CV boot, some of the boot clamps, and maybe grease (what type)?? Not sure what parts I would need in entirety to DIY this.

Do you have a link to the axle nut on Pelican's site?

[Luccia at Pelican Parts]

Originally Posted by stateofidleness

Thanks for closing the loop on this one! Guess I'll bite the bullet and get mine changed out too.

Did you buy the Hub extractor kit ($379) from Pelican as well, or did you use something else? Thinking of pulling the trigger on the kit to ensure I can do the job easily without issue (only car and daily driver so can't afford any "snags").

Anything else you recommend getting while "in there" - I was thinking: axle nut, a new CV boot, some of the boot clamps, and maybe grease (what type)?? Not sure what parts I would need in entirety to DIY this.

Do you have a link to the axle nut on Pelican's site?

If you need help we do have our DIY here: Porsche Boxster Wheel Bearing Replacement - 986 / 987 (1997-08) - Pelican Parts Technical Article.

A new CV boot is a good idea while you're in there, especially if it's an older boot. We have a complete axle boot kit that includes grease and everything you'll need for your 986 here: 2000 Porsche Boxster Base Convertible - Axles, Bearings & Differential - Page 1. We also have the wheel hub nut here (scroll down a little): 2000 Porsche Boxster Base Convertible - Axles, Bearings & Differential - Page 1. Let me know if you have any questions.

[stateofidleness]

Thanks Luccia!

Quick question - a person commented on the Tool kit stating "The lack of a hub puller" - but he mentions that was used for a 911.

Will the kit (Hub/Bearing Extractor and Installer Porsche Kit) have everything I need to do this entire job in my driveway, or am I going to need something else (but not find out till it's in pieces )

Just want to have everything planned before I tear into the car.

[Luccia at Pelican Parts]

Originally Posted by stateofidleness

Thanks Luccia!

Quick question - a person commented on the Tool kit stating "The lack of a hub puller" - but he mentions that was used for a 911.

Will the kit (Hub/Bearing Extractor and Installer Porsche Kit) have everything I need to do this entire job in my driveway, or am I going to need something else (but not find out till it's in pieces )

Just want to have everything planned before I tear into the car.

Assuming it's this one: 2000 Porsche Boxster Base Convertible - Axles, Bearings & Differential - Page 5. I'm not really sure I understand what the individuals problem was in his review, but 2 newer reviewers said they used it without any issue. I have used this one in the past with no issues as well, but it's also got a higher price tag: Wheel Bearing Tool Kit B90K - Baum Tools - | Pelican Parts. If you get the first one and run into any issues, you could follow the instructions from what that individual posted, but I don't think you'll have an issue.

[stateofidleness]

Any chance I could get a free shipping code?

$560 order (all parts qualify), but it's 36lbs... extra $20 for shipping.. almost a deal breaker

[Luccia at Pelican Parts]

Originally Posted by stateofidleness

Any chance I could get a free shipping code?

$560 order (all parts qualify), but it's 36lbs... extra $20 for shipping.. almost a deal breaker

Check your PM.