Annoying little squeak

Rambling from the Sage of Oxford
Post Reply
User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Annoying little squeak

Post by Charles » Sat Jul 14, 2018 10:23 am

As readers may have heard me mention elsewhere on the forum, I have been trying to locate (and eliminate) an annoying little squeak from the rear end. At first we thought it was coming from the rear trailing arm polybushes which were in need of lubrication after 6-7 years, but instead of just greasing them up, I decided to return to OEM rubber.

One squeak gone, another appeared!

Given that its sounding like a squeaky spring, I have decided to replace the original springs that have done 320,000 miles so far - particularly as the o/s ride height is down 6mm at the rear compared to the n/s. However, with Phil under the car as I bounced the back end up and down, we have located the real culprit - apparently the bush supporting the o/s rear spring pan arm is not happy. So, two new bushes ordered and work will start when the new springs arrive in the next few weeks.

Phil commented that he had never had to replace one of these before and I replied that he had never worked on a 320k mile E46 before!!!

And then, to add insult to injury, as I was heading home from the oil service, the water pump decided it didn't want to remain watertight any longer .... :evil:
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Thu Jul 19, 2018 1:03 am

Water pump now replaced along with all of the original pulleys and tensioners which, remarkably, had lasted all this time and mileage . New belts as well.

The engine has never sounded so quiet :D
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

rc944
ALPINA
ALPINA
Posts: 1080
Joined: Sun Sep 01, 2013 7:21 pm
Location: London / Bucks

Post by rc944 » Thu Jul 19, 2018 11:28 am

nice work

curious to learn why you never replaced springs when you recently reverted back to oe suspension?
Porsche 997.1 GT3 CS I Alpina E46 B3s Coupe I Alpina E46 B3 3.3 Touring I Ducati 749S Mono I Ducati 748R I Ducati 749 Track Bike I Ducati 916S

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Thu Jul 19, 2018 8:23 pm

rc944 wrote:curious to learn why you never replaced springs when you recently reverted back to oe suspension?
Simply because they felt fine at the time and so decided it wasn't yet necessary :D
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

rc944
ALPINA
ALPINA
Posts: 1080
Joined: Sun Sep 01, 2013 7:21 pm
Location: London / Bucks

Post by rc944 » Thu Jul 19, 2018 9:37 pm

they must have worn a lot between suspension changes to produce a 6mm reduction in rear ride height!

i ask because im about to pull the trigger on a refresh and was wondering about the springs.. there is surface corrosion on them but never thought much about it until 2 people whos judgement i trust said its sitting low at the rear
Porsche 997.1 GT3 CS I Alpina E46 B3s Coupe I Alpina E46 B3 3.3 Touring I Ducati 749S Mono I Ducati 748R I Ducati 749 Track Bike I Ducati 916S

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Thu Jul 19, 2018 11:52 pm

rc944 wrote:they must have worn a lot between suspension changes to produce a 6mm reduction in rear ride height!
I didn't measure the ride height previously - so it may well have been down but I didn't notice.

Anyway, after 320k miles, I am happy to invest in some new rear springs :D
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

rc944
ALPINA
ALPINA
Posts: 1080
Joined: Sun Sep 01, 2013 7:21 pm
Location: London / Bucks

Post by rc944 » Fri Jul 20, 2018 12:31 am

so to draw on your experience charles should the top mounts be done as a matter of course as well as spring cup pads?
Porsche 997.1 GT3 CS I Alpina E46 B3s Coupe I Alpina E46 B3 3.3 Touring I Ducati 749S Mono I Ducati 748R I Ducati 749 Track Bike I Ducati 916S

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Fri Jul 20, 2018 1:54 pm

rc944 wrote:so to draw on your experience charles should the top mounts be done as a matter of course as well as spring cup pads?
Given that I haven't changed the springs before, then I have no experience to draw upon but I would expect to change the mounts for the springs at the same time - otherwise, there is a chance they will be compromised by weak/failing mounts/pads.

However, when I changed the rear shocks, we replaced the whole top mount arrangement at the same time.
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Thu Aug 09, 2018 9:42 pm

And the squeak has gone :D :D :D

Image

Old & new - showing about 5-6mm of "sag" on the old ones. As seen in the picture, we replaced the top and bottom spring pads as well.

At the same time, we replaced the inboard bushes on both spring pan arms (which is where the squeak was coming from).

Not only has this work eliminated the squeaky rear end, but the significant vibration through the steering column on heavy braking has all but disappeared too - so clearly the old springs were causing the back end to judder under braking which transferred through the chassis to the column. In addition, one feature of Tourings is that the tailgate can get noisy over bumps and lumps - but new springs has significantly minimised this.

Of course, it goes without saying that the ride is much improved with high speed stability the most obvious difference but low speed road defects far less noticeable.

As requested, the rear ride height for an E46 B3S Touring on 18" wheels fitted with PS4 tyres - 225/40 (F) & 255/35 (R) - new springs and all other suspension components being OEM are as follows:

Offside (floor to underside of centre of arch):624mm
Nearside: 630mm

Interestingly, the 6mm difference side to side is repeated at the front:
Offside:650mm
Nearside: 656mm

Whilst under there, we spotted that the rear diff bush is cracking but because parts were not immediately available, we have decided to put this on the list for next time ...
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

ali
ALPINA
ALPINA
Posts: 2401
Joined: Sat Feb 10, 2007 12:40 am
Location: Edinburgh

Post by ali » Fri Aug 10, 2018 7:50 pm

I was always led to believe that the 6mm difference was to compensate for the weight of the driver.
This only applies to LHD vehicles though but the springs are the same for the UK and European market
B3 3.3 Coupe #090
D3 2.0 Biturbo Touring #098

User avatar
Charles
Moderator
Moderator
Posts: 8061
Joined: Mon Jun 23, 2003 2:44 am
Location: Oxford

Post by Charles » Fri Aug 10, 2018 10:14 pm

ali wrote:I was always led to believe that the 6mm difference was to compensate for the weight of the driver.
This only applies to LHD vehicles though but the springs are the same for the UK and European market
I'd heard the same thing - hence why the nearside is higher than the offside
Charles
Teacher of Chemistry and driver of ALPINAs - not necessarily in that order ;)
B3S Touring (49/116) - been to the moon and now on the way back!
Renault Grand Espace - not mine but the wife's!

AidanB10
ALPI
ALPI
Posts: 432
Joined: Wed Mar 13, 2013 12:43 am

Post by AidanB10 » Fri Aug 10, 2018 11:52 pm

BMW allow an up to 10mm difference in ride height before they say to start replacing parts, so i'd say you're fine
'00 E39 B10 V8 Saloon #456 (Weekend) - Traded
'10 E90N D3 BT Saloon #262 (Daily) -Traded
'06 E60 M5 Saloon (Daily)

Post Reply