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E30 Rear Springs and Shock Replacement
 
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Pelican Technical Article:

E30 Rear Springs and Shock Replacement

Jared Fenton

Time:

2 hours2 hrs

Tab:

$300-$400

Talent:

**

Tools:

Channel locks, 13mm socket, ratchet, 15mm socket, 15mm open-end wrench, floor jack and two jack stands, electric impact wrench, WD-40, 19mm socket, torque wrench, lug wrench, newspaper, wheel chocks, 10mm socket,

Applicable Models:

BMW E30 3-Series (1984-93)
BMW E36 3-Series (1992-99)
BMW Z3 (1996-02)

Parts Required:

Rear shocks and rear springs

Performance Gain:

Improved handling and looks via lowered appearance

Complementary Modification:

Replace front shocks and springs
101 Performance Projects for Your BMW 3 Series

This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.

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In part two of our suspension overhaul series, we will focus on replacing the rear shocks and springs in the BMW E30.

As you can see in this first photo, this is my car prior to the installation (Figure 1). The suspension on the car had seen better days. I continually noticed that the car would pitch and roll over nearly every bump in the road, indicating that the shocks were blown.

I decided to replace the stock suspension setup with a set of Bilstein Sport Shocks (Fronts shown in Figure 2) and Eibach Performance Springs. My intention was to create a suspension that I could comfortably enjoy on the street, and still retain the option to take it out to the track if I choose to do so. Also, E30’s just look killer when dropped.

The first step is to remove the bolt covers on the wheels. (Applies only to “is” style wheels). Use a set of channel locks to rotate the hub caps and remove them. See Figure 3 and Figure 4. While the vehicle is still on the ground, loosen up all the lug bolts (Figure 5). You’ll find this difficult to do when the front wheels are up in the air, unless you have an impact wrench.

Next, you will want to jack up the rear of the car. Make sure that whenever you are working with a jack, to use caution and always remember safety first. It’s a good idea to chock the front wheels from both the front and back. Keep in mind that since you will be raising the rear end off the ground, the parking brake will become useless, and there will be nothing to stop the car from rolling in the front.

With the front wheels chocked, jack the rear of the car up using the suspension crossmember. It’s a good idea to place a rolled-up newspaper in between the jack and the crossmember to prevent cutting through any undercoating or damaging the underside of the car. Once you have reached a certain height, place a jackstand under the factory jacking point on either side of the car (Figure 6). Place it under the cross-member if you are using u-shaped jack stands.

Once the car has been secured on the jack stands, the first step is to undo the straps that hold the muffler to the car (Figure 7). This is performed so that we can have clearance for the trailing arms and differential to rotate downward. Simply use a good penetrant spray on the nuts before loosening them to prevent stripping the threads. Once the nuts and straps are removed, place a jackstand under the muffler to hold it in place, and prevent possible damage to your exhaust system. The next step is to remove the front exhaust mounting bracket, located just in front of the driver’s side trailing arm. This bracket holds a rubber retainer that attaches to the exhaust system. Removing this will allow further clearance for the trailing arm and differential assembly.

Now that the exhaust system has been loosened, the next step is to remove the shocks themselves. The first step is to place the jack under the trailing arm; this will take the preload off of the trailing arm and prevent the arm from crashing downward when you try to remove the shock. Next, you will want to remove the 13mm nuts that hold the rear sway bar drop links to the trailing arm (Figure 8).

Once the sway bar links are disconnected, you will want to place a jack under the differential to support its weight. Disconnect the speedometer sender on the back of the differential. After you disconnect the sender, look up at the rear differential mount. It is essentially a large rubber bushing, with a bolt through it. Using an open-ended wrench on both sides, loosen and remove the bolt. This will allow the differential to drop down when you lower the jack (Figure 9). Note that Figure 9 shows the sender still installed - a small mistake that we realized when the wire became suddenly tight! Drop the differential slowly using your floor jack. This will lower the pivot point for the CV joints, and allow you to rotate the trailing arms down enough to remove the rear springs. When the differntial is being lowered, watch the brake cables to make sure that they don't hang up and catch on the rear sway bar.

Now, have a helper stand on the rear trailing arms, this will force the trailing arms down, and allow you to remove the rear springs. You should be able to simply pull them out (Figure 10).

With the rear springs out of the car, it’s a good time to remove the shocks from their top mounts as well. The first step in doing this is to open the rear trunk, and remove the plastic lining that runs along the inside of the trunk. There are several small tabs on the upper inside lip that simply bend down; allowing you to slowly put the liners out. Once the liners are removed, you will see the upper shock mounts. They are held in place by two 10mm nuts (Figure 11). Have a helper hold the shock from the bottom of the car and unbolt the mount. The shocks should now be free from the car. Once the shocks are free, place the shock rod in a vise and remove the self-locking nut on the top of the strut mount, this will separate the shock from the mount.

Now that the shocks are free from the mount, slip the mount over the end of the new shock and use a new self-locking nut to hold it in place. Have a helper place the new shock in the perch on the car and tighten the two 10mm nuts that hold the mount in place (Figure 12).

With the new shocks installed into their top mounts, you should install the new springs at this point. Have a helper stand on the trailing arm, and slide the new springs in place. Make sure that the upper and lower rubber spring pads are in place before doing this (Figure 13).

Once both springs are in place, you will want to place a jack under the trailing arm, and raise it until the bottom of the shock lines up with it’s mounting point on the trailing arm. Slide the lower shock absorber bolt through the shock and thread it into the trailing arm. This will keep the springs in place. See Figure 14 and Figure 15.

With the new shocks and springs installed, it is now time to reconnect the sway bar links, simply line them up in their respective positions on the trailing arm, and re-install the 10mm nuts that hold them to the control arm (Figure 16).

Now you will want to jack the differential back into position. Slowly start jacking up until the rubber mount lines up with the upper bracket and slide the mounting bolt through the bracket and mount. Using an open-end wrench and a ratchet, tighten the mount to the factory torque setting (Figure 17) .

Last is the exhaust system, First, re-attach the straps that hold the muffler in place. You may have to bend the straps a little to get them line up correctly, so use caution while bending them. Once you have them in place, simply tighten the 10mm nuts that hold the straps (Figure 7).

Next, re-install the front exhaust bracket. You will find it easier to install it at a slight angle, thread the 10mm bolt in, and then tighten it. As you tighten the bolt, it will bring the bracket back straight and hold the exhaust system in place.

Now you can re-install the tires on the car. Make sure the lug bolts are seated corrected and tighten tem as much as possible while the car is jacked up. Raise the rear of the car on either side and remove the jack stands, and lower the car onto the tires. Once the car is back on the ground, torque the lug bolts to keep the wheels from flying off. Now all you need to do is put the wheel covers back on and that’s it, you’re done!

The following pictures show the finished result, a huge improvement in the overall look of the car in my opinion. Performance wise, the car now has outstanding handling, the pitching and rolling is gone, and the car feels incredibly stable.

Figure 18: 325is lowered after installation.

Figure 19: 325is side rear view, lowered after installation.

Figure 20: 325is front close-up, lowered after installation.

If anyone has any questions regarding installation feel free to email me at The Pelican Parts Message Center

Cheers!


This technical article is made possible solely through the support of Pelican Parts. If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one.

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Comments and Suggestions:
MikesE30 Comments: I successfully replaced the front and rear springs on my '90 325i Convertible. When I took it for a test drive there is now a loud clunking sound coming from the rear driver-side. It starts off quiet but as a accelerate it gets much worse, to the point where I don't want to go any faster. I took the wheel off and everything looks to be clearing inside the wheel. Could I have damaged the gears inside the diff when I dropped it to make room for the springs to come out? I'm sort of at a loss here. Thanks for your help and all of the excellent tech articles!
September 30, 2015
  Followup from the Pelican Staff: Check if the spring is seated correctly. Then inspect the drive axles. - Nick at Pelican Parts  
Litch Comments: I'm replacing the rear coil springs on my 325i and ask what is the difference between using standard and heavy duty springs? Any recommendation?
January 19, 2015
  Followup from the Pelican Staff: I would stick with stock springs. Heavy duty, sounds like they would add spring weight to stiffen the rear end, likely for towing or added load. - Nick at Pelican Parts  
Cliff Comments: Couldn't wait for a response - was able to break free and pry free from body after pounding back and forth several times until they started to move. Horrible design for mating together without a better protectant to keep from rusting.
December 1, 2014
  Followup from the Pelican Staff: Cliff, so many questions to get to. I apologize for not being fast enough to respond, but the queue is the queue. Glad you got it worked out. - Nick at Pelican Parts  
Cliff Comments: How to remove stuck sub frame bushings on 1987 325is? Had to pull the rear sub frame from the bushings in order to remove it from the car, left torn rubber bushings and the hard core centers stuck to the body along with the upper washers and cannot get them to budge free mounting bolts have been completely removed after removing the rear seat. How do you remove them from the body?
December 1, 2014
  Followup from the Pelican Staff: Cliff got it worked out, here is his response:

Couldn't wait for a response - was able to break free and pry free from body after pounding back and forth several times until they started to move. Horrible design for mating together without a better protectant to keep from rusting. - Nick at Pelican Parts
 
Jay Comments: Nick it is for a 2003 525iT. I am converting from SLS to non-SLS.
September 25, 2014
  Followup from the Pelican Staff: Don't think we had access to an iT for these, but check here:

http://www.pelicanparts.com/BMW/techarticles/tech_main_E39.htm

Might be pretty close to yours. - Nick at Pelican Parts
 
Jay Comments: Would you have a write up on how to replace the rear springs on a touring?
September 23, 2014
  Followup from the Pelican Staff: What year and model? - Nick at Pelican Parts  
Eric Comments: The final drive mounting bolt part number is 07 11 9 914 636, by the way. Its lock nut is 07 12 9 900 047.
February 16, 2014
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help.
- Nick at Pelican Parts
 
Eric Comments: Several comments, now that I'm in the middle of the job:
- You should edit the article to say when exactly to remove the shocks, especially the lower mounting bolt.
- The lower shock mounting bolt requires Loctite on re-installation, at least per the Bilstein instructions.
- Reading the instructions closely, it seems as if one needs 2-3 floor jacks at once, to support the two trailing arms and the final drive. Really, one needs 4-5 jack stands 2 for car, 1 for exhaust system, maybe 1 for final drive, 1 for each of the trailing arms. Also, it seems better to replace springs and shocks on one side and bolt it up before beginning the other side, mostly to conserve jacks and jack stands. You may want to make note of these points at the beginning of the article.
- The final drive mounting bolt requires a new lock nut on re-installation. The mounting bolt also may need to be replaced if it breaks or rounds off on removal and Pelican doesn't currently carry the latter part.
February 16, 2014
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help. I will see if a few of your comments can be added to the article.
- Nick at Pelican Parts
 
imissmye30 Comments: I can confirm that you don't need to drop the diff or exhaust. Remove sway bar link bolt. Support brake disc with trolley jack on hub. Remove rsm nuts. Remove shock bolt getting ready to grab shock I did this without a helper. Lower jack, the spring will decompress and arm will drop some. Keep disc supported. Compress spring with compressor. The top will drop down but probably not enough to remove the spring tempting you to try and yank it out. DO NOT yank it out. The spring will be under a lot of pressure with only one compressor equaling a dangerous situation. Instead drop the jack, lo and behold the arm will drop more enabling safer removal. :
November 20, 2013
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts  
Hmm Comments: I just replaced my rear springs yesterday. I took out the shock bolt and disconnected the sway bar end link.
Used a single spring compressor and they came right out. I didn't have to mess with the exhaust or the diff.
July 14, 2013
  Followup from the Pelican Staff: Sometimes things go smooth. Good work - Nick at Pelican Parts  
Old Mal Comments: Hi Wayne, I have bmw 3series se it has been lowered,can replacing the shocks lift me up and by how much, also looking for comfort,what are the best one to buy,
June 26, 2013
  Followup from the Pelican Staff: Shock will not raise your vehicle, unless you use an adjustable height coil-over system.
Give our parts specialists a call at 1-888-280-7799. They can help you find the best parts. - Nick at Pelican Parts
 
E30949 Comments: Diff is droping far enough. Its on jack stands an factory placement. only able to drop the diff 1in mabey 2. Any help
October 7, 2012
  Followup from the Pelican Staff: You can slowly loosen the sub-frame mounts. This should get you another inch or two but under no circumstances remove the sub-frame mounting bolts entirely. It will be very difficult to re-install - Nick at Pelican Parts  
Lyle Comments: I can clarify the diff attachment/dropping issue.

E30 diffs do attach with 3 bolts. One in the rear and two the the cross member. These directions indicate that you can remove just the one attachment at the rear and the diff will drop down. This is correct IF you have your jack stands at the factory points and NOT on the cross member. If your jack stands are on the cross member it will not drop far enough and you'll have to remove the additional 2 bolts.

Highly recommend placing the jack stands on the factory locations, those 2 bolts are NOT easy to get to.
May 27, 2012
  Followup from the Pelican Staff: Thanks for the clarification to our readers - Nick at Pelican Parts  
Cruz Comments: Having the same problem as rocket and
March 7, 2012
  Followup from the Pelican Staff: Make sure the jack stands are on the chassis and not the cross-member. You need to let the cross-member drop. - Nick at Pelican Parts  
lovemybeamer Comments: I own a '1994 BMW is' I know it has rear struts, but are there rear springs as well? I do not see them.
January 24, 2012
  Followup from the Pelican Staff: If you have coil over springs on the strut assembly then no. If you have what looks like a typical shock then yes you have a separate coil spring. - Nick at Pelican Parts  
vickie Comments: i have a 325is coupe E36. i changed the rear shocks and springs but the rear is still lowered. what can i do to raise the rear of the car?. i was told that can use the 5series rear springs but since you are an expect, i will need your thoughts on that.
September 26, 2011
  Followup from the Pelican Staff: A stiffer rate spring or a longer spring will raise the car. - Nick at Pelican Parts  
Peter Comments: I need to replace a single rear spring cracked - not the shocks. Is it possible to use spring compressors and then not have to lower diff and trailing arms?
September 2, 2011
  Followup from the Pelican Staff: Yes if you use the smaller spring compressor with two threaded shaft you should have enough room to compress the spring and install it - Nick at Pelican Parts  
John Comments: Jared, you recommend upgrading to the E46 Rear Shock Mounts - but what about the front shock mounts? are hte OEM Front Shock Mounts good, or do those need to be upgraded to E46 Mounts as well? If so, what's the P/N I need to order those? THX.
June 28, 2011
  Followup from the Pelican Staff: The OEM front shock upper mount is pretty solid. Usually these are upgraded on track cars and left stock on daily drivers. - Nick at Pelican Parts  
stretch Comments: NWFL bimmer gal, I just bought a set of H&R springs for my e30 cabrio. The part # is 50407 H&R sport springs
June 15, 2011
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help. - Nick at Pelican Parts  
NWFL Bimmer Gal Comments: What springs can I use my wife has a 87 Convertible I'm not really looking to lower it as I want to use the same factory rims&tires I have heard HR makes a covert specific spring if I use Hr's can I still use my stock rims&tires. The back of the vert seems to sag time to repl springs.
March 7, 2011
  Followup from the Pelican Staff: Nice beach! HR makes very good quality springs. Give our sales department a call at 1-888-280-7799 and they can ask you some questions on what exactly you're looking to do with the car, in order to get you the right springs. - Wayne at Pelican Parts  
Jared at Pelican Parts Comments: In response to Rocket and FreeMind, I'm not sure what you guys did differently. We did lower the rear of the differential this way. Figure 9 shows it. IIRC, there is a bit of flex in the front part of the crossmember where it attaches to the differential.

Here's what the Bentley E30 manual says..

Section 13 Page 30 - removing coil springs.

" 2. Remove the rear final drive mounting bolt from the rubber mount, push the rear of the unit down, and wedge it into this lowered position using a block of wood or other suitable object" See Figure 6.4 as well.

In our case, we didnt need to wedge anything, it fell as you can see from the taught wiring connection to the speed sensor which we forgot to disconnect

I hope this clears up any confusion.
March 3, 2011
  Followup from the Pelican Staff: Thanks Jared. - Nick at Pelican Parts  
FreeMind Comments: At my car Rocket is right. The differential is fastened with actually 4 bolts to the crossmember.

In picture: "figure 6" its shown a jackstand on the crossmember.

My diff only whet down about 1 inch after i loosened the bolt in the article, but i had jackstands on the crossmember as in figure 6.

I don't have a rear sway bare either. My car is an E30 316i from 91 sold in Germany.
July 6, 2010
  Followup from the Pelican Staff: European models can vary slightly. Thanks for the additional Info. We appreciate it. - Nick at Pelican Parts  
bashleys Comments: Just a comment for those w/a cab. The shock mount bolts are not available though the truck as described, but under the top cover. A small access hatch is easily reachable negating the need to remove the fender liners...which is a pain...:
January 25, 2010
  Followup from the Pelican Staff: Thanks for the additional Info. We appreciate it. - Nick at Pelican Parts  
Jared Fenton Comments: Just a quick comment, but I highly advise anyone installing performance shocks to use upper rear shock mounts from the E46 M3 Convertible part no. 33-52-6-779-670-M10 This is a bolt-in replacement and HIGHLY adivsed over the stock mount. The OEM mounts WILL fail if you use performance shocks.
January 15, 2010
  Followup from the Pelican Staff: Thanks for the additional Info Jared. - Nick at Pelican Parts  
shlalaw Comments: I replaced my OEM rear shocks on my 1994 318is with Bilstein Touring. I also replaced the OEM external bumper stops which had disintegrated. I have since been told that the shocks have internal bumpers. Should I take the external bumpers off, or will it make any difference? Thanks.
December 29, 2009
  Followup from the Pelican Staff: I can't find any info stating to leave the factory stops off. I would contact the Bilstein help line and see if they can answer the question. I'd hate to steer you in the wrong direction. - Nick at Pelican Parts  
Bimmer1980 Comments: I installed the lowering springs and ended up with too much camber. I have wore out 2 sets of rear tires in two years. This artical needs to show installing the eccentric trailing arm bushings as well.
December 18, 2009
  Followup from the Pelican Staff: Thanks for the feedback. When performing any major suspension repair and alignment should be performed. If we get the chance to perform the camber plate procedure, we'll be sure to document it. - Nick at Pelican Parts  
Rocket Comments: Here is another article that was written by someone who has never done this job. What about the two bolts that hold the diff to the cross member? Come on guys, the diff is NEVER coming down with those attached to the cross member. Take out those two and then the mount bolt and drop it down. Incidentally, this is the same cross member that SHOULD be holding the jack stands...Check these articles carefully gents....
November 28, 2009
  Followup from the Pelican Staff: The jack stands were placed not on the cross member but at the rear factory jacking points. I think you are confusing this E30 with another car, there is no attachment point for the differential to the cross member. That doesn't make sense either way, as the differential is suspended from the chassis via the rubber mount. It wouldn't be fastened to the chassis and also suspended via a flexible mount.- Wayne at Pelican Parts  
shlalaw Comments: Replacing the rear shocks on 1994 318is OEM. 185k on car. If the springs aren't broken, is there really any reason to change them? Thanks.
November 5, 2009
  Followup from the Pelican Staff: At almost 200K on the car, they would probably begin to sag. I would replace them as it's fairly easy to do when the shocks are out of the car. - Wayne at Pelican Parts  
oldbikerider Comments: If I just want to replace the shocks can I do this without removing any of the suspension stuff, dropping diff etc?
October 31, 2009
  Followup from the Pelican Staff: You will need to follow the instructions here, which may require you to drop the differential down a few inches, but it's not very difficult. - Wayne at Pelican Parts  
Jason Comments: When lowering the differential, are you to leave it hanging, support it with a jack stand, or leave the jack under it before you must raise it again after the installation? I would imagine you would need to support it somehow.
October 19, 2009
  Followup from the Pelican Staff: It's not going anywhere when you disconnect it, as the CV joints are holding it in. Still, it's good practice to support it with a jack stand. - Wayne at Pelican Parts  
laketrout Comments: On the rear shock, how tight does the top, self locking nut suppose to be? I have inspected the 2 rear shocks, and I notice that the concave washers on each shock I can spin it around and it's just sort of flopping around. Should the self locking nut be holding them firmly in place? Is there a torque spec that I should adhere to?
June 16, 2009
  Followup from the Pelican Staff: These nuts spin with the shock, so you may be turning the actual shock. You have to hold the center rod of the shock and then tighten. I typically use an impact tool to zap these on nice and tight. - Wayne at Pelican Parts  

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