e34.535i.sport
10-26-2007, 06:20 PM
REAR SHOCK MOUNT REPLACEMENT.
Failure signs: I had a bad intermittent knocking sound from the rear (high up) when driving over rough surfaces. Also an occasional loud PING when coming off curbs etc. :(
Benefits of replacement: I got rid of the nasty and somewhat embarrassing knocking noises and the PING. I also noticed a firmer feeling from the back end when cornering and the OBC is stating a higher MPG generally now... ???! :D
TOOLS
Ok, first things first tools required for the job... (Optionals marked with a *)
+ Ratchet (preferrably 1/2" but i managed with 3/8") and various sockets.
+ Breaker bar.
+ Jack/Axel stands.
+ Mole-grip pliers or similar.
+ Gear Puller * (Almost essential though!)
+ Large flat head Screwdriver.
+ Spring compressor.
+ Various spanners (13mm-19mm)
PARTS
Obviously you will need the new mountings to replace the old ones with and i also replaced the spring pads and additional shock absorber (rubbery thing on the shock itelf). I used Dealer parts (rather expensive) but there are lots of good alternatives out there [EUROCARPARTS/GSF/BMA/ETC].
PROCEDURE
REMOVE THE SEAT...
You will need to take off the rear seat for access to the mounting bolts at the top of the shock. Start by removing the bottom part of the seat -pull up sharply on both sides to release it. Move it out the way and find the two plastic nuts that hold the bottom left and bottom right side of the top half of the seat. Undo these. There should be two more plastic nuts behind the middle armrest - pull it forward and undo these. Now you need to lift out the two headrests and use the screwdriver to undo and remove the two plastic mounts for the headrests. All you need to do now is unclip the two seatbelt carriers near the top of the seat and move the seatbelts round and remove the seat. Now what i done was put the bottom part of the seat back in place so i could use it later.
Also remove the little plastic clips that keep the parcel shelf down, and if you like remove the shelf... I kept it on but propped it up.
JACK UP THE CAR...
Jack it up on one side (my preference) and take the wheel off. Always use jack stands for safety reasons bla bla bla... Seriously though i do.
REMOVE THE LOWER MOUNTING BOLT...
After taking the wheel off have a look on the trailing arm and examine where the shock is attached to it. There's one bolt, its a big one you can't miss it. you need to loosen and remove this bolt using the breaker bar and then ratchet with the appropriate socket. There should be plenty of space.
GET THE SHOCK OFF THE TRAILING ARM...
This could take a loooooonnnnng time. At first I tried to push it off with just my hands, that wasn't happening. I briefly attempted hammering it off and that got me nowhere and if you're reusing your shock you don't want to damage it. This is where a GEAR PULLER (£13.99 from halfords etc) comes in VERY handy (Thanks Dave!). If you buy one of these you won't regret it, makes short work of removing the shock from the trailing arm. Simply hook it up and put a small socket in the hole where the bolt was to take up some space. A lot of people on this board seem to recommend supporting the trailing arm with another jack but i didn't find this necessary, but it doesn't do any harm either. Make up your own mind. Once you have got the lower end off the trailing arm you are in business.
Example gear puller...
https://sslrelay.com/buypartsby.co.uk/sealey/AK78.JPG
GET THE TOP END OFF...
Firstly, you will want to place the bottom end of the shock on the trailing arm again just a little, to save it falling down later. You may need to force down on the trailing arm a little to get the shock back on. (you will easily be able to push it off by hand later.
Now get into the back of the car and have a look at the top mounting point. There will be a big rubbery thing on top of it... pull this off. Now get the big spherical rubber peice off the top - its a bit of a b*tch to get off but persevere. Once you have that off you can see three nuts and a plate in the centre with a big bolt going though it with a nut on top (don't tough this one). Undo the three surrounding nuts and get out of the car and push the shock off the trailing arm and hold onto it as it should fall down (mine did). Some people report having to hit the top end with a hammer to release it, this may be necessary for you.
REPLACING THE MOUNTINGS...
Now that the shock is off the car you must use the spring compressor to remove the pressure from the mounting and the top nut. Be very careful while doing this (goes without saying) as it is a dangerous procedure. Some people get welding wire and twist that around some of the coils for added security. I didn't bother and had no problems. If you take your time you'll be fine, just don't rush it. Once the spring is adequately compressed you will be able to move the upper mounting around.
Now, to undo the top nut you have to use the mole grips to grab the flat part of the shock right at the top and use a spanner to turn the nut. If you don't grab the top the shock will just spin with the nut. Remove the nut and the mounting and any other peices you are replacing (note the order and placement) and put them back on in the correct order. Make sure the end of the spring meets up with the end of the upper spring pad - you'll know what i mean when you have it in front of you. If you get stuck REALOEM.COM has some great pictures to look at that may help.
Tighten the top nut up to the correct torque - 22nm (i think - someone correct me if i'm wrong), and take off the spring compressor.
REPLACE THE SHOCK.
Feed the three top bolts up through the holes at the top and push the shock back onto the mounting on the trailing arm (a bit tricky). If the trailing arm seems too high i pushed down on the caliper and it helped me get it on. Otherwise some people have said it can help to remove the rear pitman arm (replace it while there if you are). Now tighten up the bolts on top to 22nm (i think - any advances?). For the lower mounting bolt you need to torque this up while under load and for me, it didn't look possible (on the driveway!). I'm not sure if this is the best way to do it but i jacked up under the trailing arm so it was at normal ride height and torqed the bolt then let it back down (135nm i think).
Put the wheel on, lower the car and get over to the other side and do it again!
AFTERWARDS...
I couldn't beleive the difference it made, the hard work was SO worth it. The rear end is now silent over bumpy surfaces and feels much more stable. I am also getting better fuel economy according to the OBC but i'm not sure if this is correct... If not the timing and sudden change in MPG numbers as soon as i changed the mounts is a strange coincidence.
Have a look at the old ones:
http://img29.picoodle.com/img/img29/6/10/26/f_IMG0257m_e9d5fe5.jpg
http://img35.picoodle.com/img/img35/6/10/26/f_IMG0265m_ad5c2b9.jpg
PLEASE NOTE: By no means is this the only way to do this job, or even the best way its just the way i found easiest and hopefully others will find it of some use. If you have anything to add that may be helpful feel free!
Failure signs: I had a bad intermittent knocking sound from the rear (high up) when driving over rough surfaces. Also an occasional loud PING when coming off curbs etc. :(
Benefits of replacement: I got rid of the nasty and somewhat embarrassing knocking noises and the PING. I also noticed a firmer feeling from the back end when cornering and the OBC is stating a higher MPG generally now... ???! :D
TOOLS
Ok, first things first tools required for the job... (Optionals marked with a *)
+ Ratchet (preferrably 1/2" but i managed with 3/8") and various sockets.
+ Breaker bar.
+ Jack/Axel stands.
+ Mole-grip pliers or similar.
+ Gear Puller * (Almost essential though!)
+ Large flat head Screwdriver.
+ Spring compressor.
+ Various spanners (13mm-19mm)
PARTS
Obviously you will need the new mountings to replace the old ones with and i also replaced the spring pads and additional shock absorber (rubbery thing on the shock itelf). I used Dealer parts (rather expensive) but there are lots of good alternatives out there [EUROCARPARTS/GSF/BMA/ETC].
PROCEDURE
REMOVE THE SEAT...
You will need to take off the rear seat for access to the mounting bolts at the top of the shock. Start by removing the bottom part of the seat -pull up sharply on both sides to release it. Move it out the way and find the two plastic nuts that hold the bottom left and bottom right side of the top half of the seat. Undo these. There should be two more plastic nuts behind the middle armrest - pull it forward and undo these. Now you need to lift out the two headrests and use the screwdriver to undo and remove the two plastic mounts for the headrests. All you need to do now is unclip the two seatbelt carriers near the top of the seat and move the seatbelts round and remove the seat. Now what i done was put the bottom part of the seat back in place so i could use it later.
Also remove the little plastic clips that keep the parcel shelf down, and if you like remove the shelf... I kept it on but propped it up.
JACK UP THE CAR...
Jack it up on one side (my preference) and take the wheel off. Always use jack stands for safety reasons bla bla bla... Seriously though i do.
REMOVE THE LOWER MOUNTING BOLT...
After taking the wheel off have a look on the trailing arm and examine where the shock is attached to it. There's one bolt, its a big one you can't miss it. you need to loosen and remove this bolt using the breaker bar and then ratchet with the appropriate socket. There should be plenty of space.
GET THE SHOCK OFF THE TRAILING ARM...
This could take a loooooonnnnng time. At first I tried to push it off with just my hands, that wasn't happening. I briefly attempted hammering it off and that got me nowhere and if you're reusing your shock you don't want to damage it. This is where a GEAR PULLER (£13.99 from halfords etc) comes in VERY handy (Thanks Dave!). If you buy one of these you won't regret it, makes short work of removing the shock from the trailing arm. Simply hook it up and put a small socket in the hole where the bolt was to take up some space. A lot of people on this board seem to recommend supporting the trailing arm with another jack but i didn't find this necessary, but it doesn't do any harm either. Make up your own mind. Once you have got the lower end off the trailing arm you are in business.
Example gear puller...
https://sslrelay.com/buypartsby.co.uk/sealey/AK78.JPG
GET THE TOP END OFF...
Firstly, you will want to place the bottom end of the shock on the trailing arm again just a little, to save it falling down later. You may need to force down on the trailing arm a little to get the shock back on. (you will easily be able to push it off by hand later.
Now get into the back of the car and have a look at the top mounting point. There will be a big rubbery thing on top of it... pull this off. Now get the big spherical rubber peice off the top - its a bit of a b*tch to get off but persevere. Once you have that off you can see three nuts and a plate in the centre with a big bolt going though it with a nut on top (don't tough this one). Undo the three surrounding nuts and get out of the car and push the shock off the trailing arm and hold onto it as it should fall down (mine did). Some people report having to hit the top end with a hammer to release it, this may be necessary for you.
REPLACING THE MOUNTINGS...
Now that the shock is off the car you must use the spring compressor to remove the pressure from the mounting and the top nut. Be very careful while doing this (goes without saying) as it is a dangerous procedure. Some people get welding wire and twist that around some of the coils for added security. I didn't bother and had no problems. If you take your time you'll be fine, just don't rush it. Once the spring is adequately compressed you will be able to move the upper mounting around.
Now, to undo the top nut you have to use the mole grips to grab the flat part of the shock right at the top and use a spanner to turn the nut. If you don't grab the top the shock will just spin with the nut. Remove the nut and the mounting and any other peices you are replacing (note the order and placement) and put them back on in the correct order. Make sure the end of the spring meets up with the end of the upper spring pad - you'll know what i mean when you have it in front of you. If you get stuck REALOEM.COM has some great pictures to look at that may help.
Tighten the top nut up to the correct torque - 22nm (i think - someone correct me if i'm wrong), and take off the spring compressor.
REPLACE THE SHOCK.
Feed the three top bolts up through the holes at the top and push the shock back onto the mounting on the trailing arm (a bit tricky). If the trailing arm seems too high i pushed down on the caliper and it helped me get it on. Otherwise some people have said it can help to remove the rear pitman arm (replace it while there if you are). Now tighten up the bolts on top to 22nm (i think - any advances?). For the lower mounting bolt you need to torque this up while under load and for me, it didn't look possible (on the driveway!). I'm not sure if this is the best way to do it but i jacked up under the trailing arm so it was at normal ride height and torqed the bolt then let it back down (135nm i think).
Put the wheel on, lower the car and get over to the other side and do it again!
AFTERWARDS...
I couldn't beleive the difference it made, the hard work was SO worth it. The rear end is now silent over bumpy surfaces and feels much more stable. I am also getting better fuel economy according to the OBC but i'm not sure if this is correct... If not the timing and sudden change in MPG numbers as soon as i changed the mounts is a strange coincidence.
Have a look at the old ones:
http://img29.picoodle.com/img/img29/6/10/26/f_IMG0257m_e9d5fe5.jpg
http://img35.picoodle.com/img/img35/6/10/26/f_IMG0265m_ad5c2b9.jpg
PLEASE NOTE: By no means is this the only way to do this job, or even the best way its just the way i found easiest and hopefully others will find it of some use. If you have anything to add that may be helpful feel free!