low-speed squeaking from front wheel

[Otter74]

Last weekend I made the time to go for a drive for the first time in a month, and the second time this year. On the way home I found myself in the not-unexpected stop-and-go traffic from the ORD toll gate most of the way home. There I heard for the first time an unexpected squeaking from, as best I can tell, the left front wheel. Could be the rear, but I think it's the front (I could hear it reflecting off the barrier wall and would listen for when it changed slightly as a car passed me.)

The noise is audible only at very low speeds - presumably everything else masks it above 15mph or so. It occurs once per wheel revolution and is accompanied by a momentary resistance each time - analogous to a brake pad dragging on a bump in a slightly out-of-true bicycle wheel. You feel this in the chassis, not in the brake pedal. Brake application has no apparent effect on it.

I cannot think of anything other than the wheel bearing that could be the source of the symptoms, but at the same time I can't obviously think of how a wheel bearing could be displaying this symptom. I won't entirely exclude a brake issue like a sticking caliper or slide pin until I can inspect that, too.

I did attempt to do a search for this, but did not find anything in past discussions that seemed to fit.

I will have time this weekend to jack up the front end and inspect/tug on the wheel; I hope that will give me some clues. In the meantime, anything?

[86 911 Targa]

You are on the right track.

Did my bearings last year.

Follow through, ask for help as needed.

Best,

Gerry

[Otter74]

Ok, finLly had time to look at it yesterday. Put the front end up, did the top-bottom push-pull with the wheel on, and yes, there's a little bit of play. Checked the other side for reference, no play. There was also more drag in this wheel than on the other one. So either the bearings need adjustment or they need replacement.

I take the wheel off and remove the dust cap:



Nothing abnormal looking. Is the play correct? Per the push-on-the-washer test. Seems a little tight, as there's no movement in it. I back the lock nut off about 1/8 turn and that seems about right in terms of play.

So I still don't know what could have been squeaking; all I know is I had that squeaking and the pulsing drag and I do seem to have play in the bearing. Given that it also may have been adjusted slightly tight, it doesn't seem to me that adjusting it is going to take care of the play. Am I wrong? I know these are noob questions but none of my other cars have had user-serviceable wheel bearings, so I'm new to it.

[Jack Stands]

My '87 Cabriolet had a similar issue and it was a bad bearing. The noise was only intermittent and more pronounced when turning, but when we disassembled the front hub, replacing the slightly worn bearing corrected the problem.

[cabmandone]

If you have noticeably more drag on one side, I'd check your brake pads to make sure you don't have a caliper hanging. Both sides of my car had play but the effort to turn was the same. I got a noticeable bearing noise when I loaded each side going through turns.

[Bob Kontak]

I think an entire set of bearings and seals is you mission. It's cheap. Some grunt work.

However, with respect to cabmando's post, put the rotor on and spin it. You should run into your snag. The resistance.

[Swoboda]

I had the same sound--it was the bearings.

If you replace one, do the other, too. The other one can't be too far behind...

[RSTarga]

Change out your rubber brake lines too.

[safe]

Originally Posted by Otter74

Nothing abnormal looking. Is the play correct? Per the push-on-the-washer test. Seems a little tight, as there's no movement in it. I back the lock nut off about 1/8 turn and that seems about right in terms of play.

So I still don't know what could have been squeaking; all I know is I had that squeaking and the pulsing drag and I do seem to have play in the bearing. Given that it also may have been adjusted slightly tight, it doesn't seem to me that adjusting it is going to take care of the play. Am I wrong? I know these are noob questions but none of my other cars have had user-serviceable wheel bearings, so I'm new to it.

The move washer test is junk in my opinion. Try to rock the wheel in the 12 and 6 a clock position. You should have a small amount of play, nothing big.

Worn bearings usually rumbles and don't squeak, but it should not be ruled out. Time will tell if you care to wait...

[sugarwood]

That red grease looks fresh. Or does it not age?

[Otter74]

Originally Posted by cabmando

If you have noticeably more drag on one side, I'd check your brake pads to make sure you don't have a caliper hanging. Both sides of my car had play but the effort to turn was the same. I got a noticeable bearing noise when I loaded each side going through turns.

Yeah, I thought of that, so I'll check the pad wear when I a move at the car later today. I do suspect that caliper may be dragging slightly; the car seems to have a slight pull to the left that is intermittent. I have not had any of the typical bearing rumbling noises, though.

Originally Posted by safe

The move washer test is junk in my opinion. Try to rock the wheel in the 12 and 6 a clock position. You should have a small amount of play, nothing big.

Worn bearings usually rumbles and don't squeak, but it should not be ruled out. Time will tell if you care to wait...

Why do you consider that test to be no good? I have no play in the right wheel and a little bit in the left. Later today I a man going to tighten the left side bearing just a tad, just enough to take the play out and make it like the right side, then take the car for a drive and listen for the squeaking and any other symptoms. If it's ok, I'll probably take the car on the trip but order new bearings and replace them in May anyway.

[Dmitry at Pelican Parts]

In case anyone needs to do their front wheel bearings, check out the link below. I've also attached the general link to all our DIYs.

Porsche 911 Front Wheel Bearing Replacement | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

Porsche 911 (1965-1989) Technical Articles - Pelican Parts


-Dmitry

[Peter Zimmermann]

A test we used to do for this diagnosis is to make the noise audible, then maintain that speed with your throttle while you apply gentle pressure to the brake using your left foot. Noise goes away (and it probably will)? Problem is a sticky caliper or a bad brake hose, both will cause pad drag.

[RSTarga]

Squeel+brakes or shield
Rumble+bearing.

[wayner]

My bearing sounded like "a machinists lathe at low speed"
when I noticed it as I coasted up to a gas pump

cruck,cruck,cruck, weee, crunch cruck,cruck,cruck,




Saving a 73 from the crusher...

[Otter74]

Originally Posted by Peter Zimmermann

A test we used to do for this diagnosis is to make the noise audible, then maintain that speed with your throttle while you apply gentle pressure to the brake using your left foot. Noise goes away (and it probably will)? Problem is a sticky caliper or a bad brake hose, both will cause pad drag.

Good idea; I'd checked for that when I first heard it by applying the brake, but I didn't hold speed with the throttle.

Originally Posted by RSTarga

Squeel+brakes or shield
Rumble+bearing.

I spent some time on the car last night and checked the dust shield again - I'd checked it the other day as soon as I took the wheel off and saw no evidence of contact (a bent dust shield and a bit of runout in the rotor, or a bit of wobble from a loose bearing, could do it) and saw none. But I forgot to check the bottom side. Looked at that last night and there was a tiny bit of contact. Straightened that out and tighened the bearing slightly, took it for a drive. Now an additional squeak/squeal near stop, but otherwise the same. No change in bearing feel after driving.

Originally Posted by wayner

My bearing sounded like "a machinists lathe at low speed"
when I noticed it as I coasted up to a gas pump

cruck,cruck,cruck, weee, crunch cruck,cruck,cruck,

Useful description I guess I could describe mine like that (thanks, YouTube), with the 'weee' but not the cruck-cruck-cruck. Then again, the cruck-cruck is harder to hear over ambient.


The PO (who had the car from 2000 to 2015) replaced at least one front wheel bearing and repacked them periodically but couldn't remember which one he had replaced. I'm leaning towards the right side. He never split the calipers so I wouldn't be surprised if, independent of a possible bearing issue, I have a draggy caliper that could use a rebuild.

My main concern now is whether to take the car on my trip or not. I don't think I have time to do it myself before I go, and I don't think I have time to take it to a shop, either.

[wayner]

Youtube?

Slow down the revolutions a bit but similar in some ways

[Otter74]

Yeah, it's been a long time since I've spent much time in machine shops, so I had to go to YouTube. Mine is very clearly once per wheel revolution, the kind of thing I would normally associate with something external.

By the way, your build thread is terrific.

Originally Posted by wayner

Youtube?

Slow down the revolutions a bit but similar in some ways

[wayner]

Build thread ?

Here is the sequel.

Saving a 73 from the crusher...AGAIN

[Otter74]

Well, I've got new bearings and seals on the way as even if it turns out not to need them, they're cheap and will be good to have on hand. And a caliper rebuild kit too, as it does seem draggy. I confirmed with the PO (who owned the car for 15 years) that both bearings had been serviced but only one had been replaced and he couldn't remember which, and the calipers had never been touched.

I am going to give one more go at seeing if I can adjust the play out, though I'm doubtful. I note that one is instructed to turn the hub/rotor as you tighten the nut - why is that?

If no change, I will either roll the dice and drive the car anyway and then do the bearing job in another couple of weeks, or try to get it all done on Saturday. Seems relatively straightforward though with some potential sticking points for the first-timer. I am a competent home mechanic (I DIY all my cars) but this is a new job for me.


-How much time can I expect this to take, given the above qualifier? I will add 50% fort conservatism's sake. Is freezing the bearings and heating up the hub going to make a worthwhile difference in how easily everything slips in and out? (I would be doing this in my girlfriend's apartment - fortunately she is understanding!)

-Is a seal removal tool really worth getting?

-I have read the how-to in the book/here, and am looking through other threads. What works particularly well as right-sized drifts? E.g. the 3/4" socket mentioned somewhere.

-Best way to minimize brake fluid loss when I remove the caliper to make bleeding quick? Just a plug in the line? Not sure if I'll have time to service the caliper and do the bearing both.