wheel bearings ?
#1
Track Day
Thread Starter
wheel bearings ?
hi
i have got a technical question i'm putting out to the mighty rennlist brain.
took my lovely 2012 c2s out the other day (doesn't get much use in the winter unless dry and warmish) and noticed a sound best described as 'droning' from the rear.
only noticeably on the move. becomes pronounced at 40-50mph and is drowned out by other sounds by about 70ish (not that i would ever go faster than that...) it does not change with engine load or braking just speed, and is the same in any gear including coasting in neutral.
its done 34k now and has definitely had a few heat cycles with the occasional track day. perhaps 600miles on track with me over the last 4 years so the bearings have been quite warm at times.
no other symptoms, gearbox works nicely when up to temperature, engine spins up fine with no untoward sounds. i did jack it up and see if can be wobbled, but doesn't seem to be any play on either rear wheel.
unless any other suggestions i'm guessing a wheel bearing, its due for a service in a few weeks so will leave it until then unless its possibly more serious as probably wont do more than another 500 miles or so in that time as dont use it day to day until gets a bit warmer and less damp.
thank you in advance.
i have got a technical question i'm putting out to the mighty rennlist brain.
took my lovely 2012 c2s out the other day (doesn't get much use in the winter unless dry and warmish) and noticed a sound best described as 'droning' from the rear.
only noticeably on the move. becomes pronounced at 40-50mph and is drowned out by other sounds by about 70ish (not that i would ever go faster than that...) it does not change with engine load or braking just speed, and is the same in any gear including coasting in neutral.
its done 34k now and has definitely had a few heat cycles with the occasional track day. perhaps 600miles on track with me over the last 4 years so the bearings have been quite warm at times.
no other symptoms, gearbox works nicely when up to temperature, engine spins up fine with no untoward sounds. i did jack it up and see if can be wobbled, but doesn't seem to be any play on either rear wheel.
unless any other suggestions i'm guessing a wheel bearing, its due for a service in a few weeks so will leave it until then unless its possibly more serious as probably wont do more than another 500 miles or so in that time as dont use it day to day until gets a bit warmer and less damp.
thank you in advance.
#2
Rennlist Member
Jack up the rear (each side independently) and see if there is any play in the bearing by firmly trying to “wobble” the wheel by grabbing the tire and move it in and out w side to side motion! Rotate the tire 1/4 and try in 4 axis! If any movement, you have probably found your problem: wheel bearing! Hope this helps. Btw they are not that expensive to replace, $3-400 per wheel. Just do the one that needs it!
#3
Track Day
Thread Starter
Jack up the rear (each side independently) and see if there is any play in the bearing by firmly trying to “wobble” the wheel by grabbing the tire and move it in and out w side to side motion! Rotate the tire 1/4 and try in 4 axis! If any movement, you have probably found your problem: wheel bearing! Hope this helps. Btw they are not that expensive to replace, $3-400 per wheel. Just do the one that needs it!
i shall give that a try tomorrow and see how get on. Didn't know about the turn it a small amount trick.
#4
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When it was jacked up did you check the integrity of the bellows (rubber boots) for the CV joints on the 1/2-shafts?
#5
Instructor
I have a similar problem with my car - 2013 C2 Base with about 20k miles on it; I just bought it few weeks ago and the problem came with the car.
Took it to two different indys and had it checked. First shop said it was just tire noise. Which it could be in this case too - caused by out of spec alignment with uneven tire wear. My tires however are brand new.
Second shop found no play in the wheel at any corner, but on rotation of the right rear wheel, there is vibration felt at the rear of the hub assembly. This is a wheel bearing failure. Having it replaced tomorrow.
Took it to two different indys and had it checked. First shop said it was just tire noise. Which it could be in this case too - caused by out of spec alignment with uneven tire wear. My tires however are brand new.
Second shop found no play in the wheel at any corner, but on rotation of the right rear wheel, there is vibration felt at the rear of the hub assembly. This is a wheel bearing failure. Having it replaced tomorrow.
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#6
Track Day
Thread Starter
nothing obvious to be found.
thanks for the tips, seems bearings dont live forever.
its done about 35k miles.
so jacked it up and checked the wheels for play, nothing that i could notice on any of them. and all the cv boots looked to be intact.
i did noticed that somehow i ended up with p-Zero tyres which are not porsche rated (thanks quickfit) they have been on for a year and 5000 miles, so could be related slightly wrong spec tyres wearing down.
last year the alignment was out after some potholes so quite likely the same again, and the rear passenger side tyres have definitely got a bit more wear on them than the drivers side. here in the uk we have a lot of roundabouts. they all go clockwise. and often late at night they are empty and well sighted and brings out the child in all of us. i wonder if its possible one side is wearing faster than the other due to this.
i may take it out later for an 'italian tune' and see if can find any way to even up the wear on the rear. see if that helps.
otherwise its off to the garage, due a service in a few weeks so will wait until then as it doesn't seem to be anything too urgent. so will definitely ask them to check the alignment and bearings when its in.
its done about 35k miles.
so jacked it up and checked the wheels for play, nothing that i could notice on any of them. and all the cv boots looked to be intact.
i did noticed that somehow i ended up with p-Zero tyres which are not porsche rated (thanks quickfit) they have been on for a year and 5000 miles, so could be related slightly wrong spec tyres wearing down.
last year the alignment was out after some potholes so quite likely the same again, and the rear passenger side tyres have definitely got a bit more wear on them than the drivers side. here in the uk we have a lot of roundabouts. they all go clockwise. and often late at night they are empty and well sighted and brings out the child in all of us. i wonder if its possible one side is wearing faster than the other due to this.
i may take it out later for an 'italian tune' and see if can find any way to even up the wear on the rear. see if that helps.
otherwise its off to the garage, due a service in a few weeks so will wait until then as it doesn't seem to be anything too urgent. so will definitely ask them to check the alignment and bearings when its in.
#7
Rennlist Member
Does Porsche specify wheel bearing re-packing and adjustment after X number of miles? They did on older cars.
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#8
Instructor
thanks for the tips, seems bearings dont live forever.
its done about 35k miles.
so jacked it up and checked the wheels for play, nothing that i could notice on any of them. and all the cv boots looked to be intact.
i did noticed that somehow i ended up with p-Zero tyres which are not porsche rated (thanks quickfit) they have been on for a year and 5000 miles, so could be related slightly wrong spec tyres wearing down.
last year the alignment was out after some potholes so quite likely the same again, and the rear passenger side tyres have definitely got a bit more wear on them than the drivers side. here in the uk we have a lot of roundabouts. they all go clockwise. and often late at night they are empty and well sighted and brings out the child in all of us. i wonder if its possible one side is wearing faster than the other due to this.
i may take it out later for an 'italian tune' and see if can find any way to even up the wear on the rear. see if that helps.
otherwise its off to the garage, due a service in a few weeks so will wait until then as it doesn't seem to be anything too urgent. so will definitely ask them to check the alignment and bearings when its in.
its done about 35k miles.
so jacked it up and checked the wheels for play, nothing that i could notice on any of them. and all the cv boots looked to be intact.
i did noticed that somehow i ended up with p-Zero tyres which are not porsche rated (thanks quickfit) they have been on for a year and 5000 miles, so could be related slightly wrong spec tyres wearing down.
last year the alignment was out after some potholes so quite likely the same again, and the rear passenger side tyres have definitely got a bit more wear on them than the drivers side. here in the uk we have a lot of roundabouts. they all go clockwise. and often late at night they are empty and well sighted and brings out the child in all of us. i wonder if its possible one side is wearing faster than the other due to this.
i may take it out later for an 'italian tune' and see if can find any way to even up the wear on the rear. see if that helps.
otherwise its off to the garage, due a service in a few weeks so will wait until then as it doesn't seem to be anything too urgent. so will definitely ask them to check the alignment and bearings when its in.
my car is a 2013 991.1 Base - wheel bearing at rear right failed at 19,000 miles.
I had the same noise you describe above. Today I replaced that bearing and now noise is gone.
#9
Rennlist Member
Any documented DIY's out there yet for bearing replacement?
Are they pressed in and out like most other installations?
Are they pressed in and out like most other installations?
#10
Instructor
https://rennlist.com/forums/991/1174...991-1-a-6.html
Post #89
Axle nut torque spec is 340 ft/Ibs.
#11
Track Day
Thread Starter
yup. was wheel bearing on one side at the rear. replaced by garage and all is well again.
now all i need is some nice sunny spring days here in englandshire to wear it out all over again!
now all i need is some nice sunny spring days here in englandshire to wear it out all over again!
#12
Rennlist Member
They are pressed in but not by much force. It does help having a hydraulic press though. I did a set of rear wheel bearings on a friend's 993. Used my press.
Lets hope they did it right. You press them in using the outer race and not the inner race when it is going into a cavity. On the other hand, when pressing them onto a shaft, you press them on using the inner race. Doing it right is how to make bearings last. Hammering is a no-no.
I can't believe some of these bearings only lasted 19K or 35K miles.
I forgot to mention, checking play and feeling a bearing by rotating it is no sure way of telling the bearing is good. My friend's 993 was making a bearing noise (fan bearing) and when taken apart, it felt as good as any other new bearing. But it did resonate while running. A new bearing solved it.
Lets hope they did it right. You press them in using the outer race and not the inner race when it is going into a cavity. On the other hand, when pressing them onto a shaft, you press them on using the inner race. Doing it right is how to make bearings last. Hammering is a no-no.
I can't believe some of these bearings only lasted 19K or 35K miles.
I forgot to mention, checking play and feeling a bearing by rotating it is no sure way of telling the bearing is good. My friend's 993 was making a bearing noise (fan bearing) and when taken apart, it felt as good as any other new bearing. But it did resonate while running. A new bearing solved it.
Last edited by IXLR8; 02-27-2020 at 05:11 PM.
#15
RL Community Team
Rennlist Member
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