The rear axle carrier, what most people call the rear subframe, is the cast piece that spans the back of the car and carries the final drive and both trailing arms. It hangs off the body on a pair of rubber bushings, and after thirty years those bushings go to mush. When they do, the whole rear end shifts under power. You bang second gear and the back of the car steps sideways, you get a clunk on throttle on and off, and the car feels like it has a mind of its own over bumps. New bushings put the geometry back where BMW drew it.
This is not a Saturday job. To get at the subframe bushings you have to drop the final drive, disconnect the rear brakes, and lower the whole carrier out of the car. Budget a long weekend, plan on bleeding the brakes at the end, and read the whole thing before you spin a single bolt.
Read This First: Safety
The car cannot rest on the back end while you do this, because you are removing the back end. Support the body on jack stands rated for the job, placed at the body jacking points, never under the subframe or trailing arms you are about to remove. Get the car high enough to work and to slide the carrier out from under it, and rock it hard before you go underneath.
CAUTION: You are opening the brake hydraulic system to pull the trailing arms, so the brakes come apart and have to be bled before the car moves again. Brake fluid is poison and strips paint, so wear gloves and glasses and wipe spills off the body right away. Do not drive the car until you have a firm pedal.
NOTE: A common shortcut is to burn the old bushings out with a torch while the subframe is still under the car. Do not do that. The fuel tank and fuel lines sit right there. Drop the carrier first and do any heat work on the bench, well away from the tank.
Before You Start
Be honest about whether you need this. Worn rear subframe bushings give a specific feel: the rear of the car wanders or "crab walks" under hard acceleration and again when you lift, and there is a clunk that tracks with throttle, not with the suspension going over bumps. If your clunk is bump-related, look at the rear shock mounts, the sway bar links, and the trailing arm bushings first, those are far less work. A loose front subframe and worn mounts make their own noise up front, and the rear carrier behaves the same way when its bushings let go.
Plan on doing the trailing arm bushings too. With the carrier out and the trailing arms off, the trailing arm bushings are right in front of you, and they wear on the same clock. These are pressed in, and BMW specifies special tools to remove and install them. If you are going to all this trouble, do them now. Even if they still look good when they come out, replacing them while everything is apart is the right call.
This is a press-and-special-tool job, not a hammer job. The subframe bushings and the trailing arm bushings are both pressed fits. You need a press or a strong puller setup. People have improvised with threaded rod, sockets, and a vise, and some people have used a shop press or even a wood splitter, but understand going in that you cannot just beat these in and out cleanly.
Order new self-locking nuts before you start. BMW makes the self-locking nuts on the final drive, the rear shock upper mounts, and elsewhere one-time-use. Have replacements on hand so you are not reusing tired nuts on the parts that hold your driveline up.
What You're Replacing
You are renewing the two rubber bushings that hold the rear axle carrier to the body, and, while you are in there, the trailing arm bushings. Everything else comes off only to get at them. The diagram at the top of this guide shows how the carrier, trailing arms, and final drive stack up.
| Part | OEM part no. | Notes |
|---|---|---|
| Rear subframe (axle carrier) bushings | 33 31 1 129 144 | The two rubber mounts between the axle carrier and the body. The reason you are here. Pressed in. |
| Trailing arm bushings (inner and outer) | 33 32 9 061 945 | Pressed into each trailing arm. Each has a larger-diameter shoulder on one end that always faces away from the arm. Do these while the carrier is out. |
| Final drive rubber mounting bushing | 33 17 1 135 242 | The bushing at the rear nose of the final drive. Eccentric, and easy to renew while the diff is down. Worth doing if it is cracked. |
| Self-locking nuts (final drive, shock mounts) | n/a | One-time-use. Replace any you remove. |
The subframe bushings are sold as a pair and are chassis-specific, so confirm the part against your VIN before ordering, and note that the iX uses different parts. Polyurethane and reinforced rubber options exist, but a stock rubber bushing keeps the ride the way BMW intended and is the right call for most cars.
What You'll Need
| Part | OEM part no. | Notes |
|---|---|---|
| Rear subframe (axle carrier) bushings | 33 31 1 129 144 | Sold as a pair. The 325iX uses 33 31 1 128 990 (taller center sleeve, not interchangeable). |
| Trailing arm bushings | 33 32 9 061 945 | The standard set, inner and outer per side. The eccentric toe-adjustable version is 33 32 9 058 822. |
| Final drive rubber mounting bushing (optional) | 33 17 1 135 242 | Renew if cracked while the diff is down. The iX uses a different part. |
| Self-locking nuts | n/a | New ones for the final drive and the rear shock upper mounts. |
| Exhaust coupler gasket and hardware | n/a | The rear section comes down; have a coupler gasket and fresh nuts and bolts. |
| DOT 4 brake fluid | n/a | You are opening and bleeding the system. |
| Anti-seize | n/a | For the body-mount studs and the bolts that fought you. |
These are the genuine BMW numbers for the standard rear-wheel-drive E30. The 325iX rear subframe and driveline differ, and BMW has superseded some of these over the years, so confirm each part against RealOEM or FCP Euro by your VIN before ordering. Polyurethane and reinforced rubber options exist, but stock rubber keeps the ride the way BMW intended.
| Tool | For |
|---|---|
| Jack stands (body-rated) and a floor jack | Holding the car and supporting the final drive as it comes down |
| Transmission jack or a second floor jack | Lowering the axle carrier in a controlled way |
| Hex (Allen) sockets, 6 mm | The inner CV joint bolts and the subframe-mount screws. Sockets flex less than wrenches |
| Metric sockets and wrenches, 11 to 22 mm | General teardown; 17 and 19 do most of the work |
| Flare-nut (line) wrench | The rear brake line union, so you do not round it off |
| Shop press or a heavy-duty puller setup | Pressing the subframe and trailing arm bushings |
| Penetrating oil (PB Blaster is our pick) | The exhaust hardware and the body-mount studs |
| Torque wrench | The final drive, axle, and brake fasteners that do have specs |
| Vacuum or pressure bleeder, or a helper | Bleeding the brakes afterward |
Step 1: Soak the Fasteners and Get the Car Up
Spray everything you are about to fight with penetrating oil, PB Blaster is what we swear by, and give it time. The worst offenders are the rear exhaust coupler hardware and the body-mount studs at the subframe. Hit them now and again an hour later.
Loosen the rear lug bolts, then raise the body and set it on stands at the body jacking points, high enough that the carrier will clear when it drops. Pull the rear wheels. Drop the rear section of the exhaust at the coupler and suspend it or set it aside, lowering it only as far as needed and supporting it with wire so you do not tweak the rest of the system.
Step 2: Disconnect and Support the Drive Axles
Before anything hangs free, deal with the axles. With the car still on the ground, pry the dust cap off each rear hub, lift the lockplate, and just loosen the big axle nut. Doing it on the ground is a safety rule, the leverage can topple the car off stands.
Back up on the stands, clean around each inner CV joint and remove the six internal-hex-head bolts that hold it to the final drive flange. One thing to get right: do not let the inner end of the axle hang free, it can damage the outer CV joint. Hook the inner end up with stiff wire so the axle sits near its installed angle.
Step 3: Drop the Final Drive
Mark the driveshaft and the final drive input flange so they go back in the same clock position, then unbolt the driveshaft from the diff and tie it up out of the way with wire. Do not let it hang off the center bearing, and keep it off the fuel tank line.
Disconnect the speedometer pulse sender wiring. Put a jack under the final drive to take its weight, then pull the mounting bolts. The factory order is the two rear bolts on top of the carrier first, then the two front bolts, then the nut and bolt for the rubber mounting bushing at the nose. Lower the diff and get it out from under the car. It is heavy, it is roughly seventy pounds, so let the jack carry it.
NOTE: You will see the driveshaft pulled last in some writeups instead of following the factory order. There is no harm either way, but the diff has to come fully off the car here, not just hang, so disconnect both ends and the mounts and set it aside.
Step 4: Disconnect the Rear Brakes and Parking Brake
The trailing arms have to come down with the carrier, so the brakes come apart. Disconnect the rear brake line at the union near each trailing arm inner mount using a flare-nut wrench, not an open-end, the soft line nut rounds off instantly. Plug or cap the lines to keep dirt out and limit the drip.
Disconnect the parking brake cable. To free it you have to get into the parking brake mechanism behind the rotor, which means pulling the caliper and rotor on each side. Suspend each caliper from the body with wire so it never hangs by its hose. If a bleeder screw is already seized or snapped, note it now, that is a separate fight and a hint your whole rear brake system is due.
CAUTION: Do not let any caliper hang by its brake hose. The hose will kink or tear and set you up for brake failure later. Wire it up every time it comes loose.
Step 5: Lower the Trailing Arms and Remove the Springs
Disconnect the rear sway bar from its links or the links from the trailing arms. Then disconnect the lower shock mount on each trailing arm. As the arm swings down, the coil spring unloads, push down on the hub and lift the spring out by hand, noting the rubber pad that sits between the spring and its seat so it goes back.
CAUTION: Support each trailing arm as you lower it. Letting it drop to full extension on the axle stresses the CV joints, and you have already gone to the trouble of protecting them. Lower the arm only as far as you need to free the spring.
This is also the moment, if you are renewing rear shocks, to pull the upper shock mounts from inside the trunk. It buys room and the upper nuts live a sheltered life, so they usually come off easily. Use new self-locking nuts on the upper mounts going back.
Step 6: Lower the Rear Axle Carrier Out of the Car
Do a last walk-around. Anything still tied to the carrier or the arms (a wire zip-tied near the fuel tank on the driver's side is a common one) gets freed now. It is easy to miss one.
Put a transmission jack or a second floor jack under the carrier to take its weight. Then remove the carrier-to-body fasteners. On these cars that is four hex-head screws set into the body just rearward of the rear jacking points, plus the large nuts on the bottom of the body-mount studs. The hex screws are the ones that ruin days.
CAUTION: Do not run an impact gun on the four hex screws. They strip if you do. Put a hex socket fully into the head, and if it still will not turn, grip the socket or screw with vise grips and work it by hand. Heat and patience beat speed here.
With the fasteners out, the carrier may still be stuck on its locating studs and crusty bushings. Work it down evenly with a pry bar, and if one side breaks free first, use it as a lever to twist the other side loose. Lower the whole carrier, trailing arms still attached, and slide it out.
Step 7: Press Out the Old Bushings, Clean the Mounts
With the carrier on the bench, separate the trailing arms if you are doing their bushings. To pull a trailing arm, the arm just unbolts at its inner and outer mounts on top of the carrier once the brake and axle work above is done.
Press the old subframe bushings out of the carrier and the old bushings out of the trailing arms. A press is the clean way. If a bushing is truly seized, a hacksaw cut through the rubber and the metal sleeve relieves it, the same trick that works on the final drive bushing, just do not cut into the carrier or arm itself. This is also where, with the part on the bench and nowhere near the fuel tank, you can use heat to soften a stubborn bushing.
NOTE: Sometimes the metal sleeve of a subframe bushing shears and leaves a ring stuck in the body mount. The fix: drill a few shallow holes into the stuck aluminum, then split it with a punch and it comes out in pieces. Mark your drill depth so you do not punch through, it is easy to go too far.
Clean the carrier mounts and the body mounts down to clean metal. Knock off the surface rust and check the body mounts for cracks while you have a clear view, this is the one time you will see them.
Step 8: Press In the New Bushings
Press the new bushings into the carrier and the trailing arms. Soap or the lubricant supplied with the bushing helps them start and seat. On the trailing arm bushings, orientation matters: the larger-diameter shoulder always faces away from the arm, so the inner bushing's shoulder faces the center of the car and the outer bushing's shoulder faces outward.
If you bought eccentric trailing arm bushings to set rear toe, their installed angle is what determines the toe change, so set them to the marks deliberately and note that the maximum is a quarter turn, 90 degrees, either way. Concentric (standard) bushings need no clock position, press them straight in.
Step 9: Reassemble the Carrier and Lift It Back In
Reattach the trailing arms to the carrier. When you torque the trailing arm mounting bolts, start with the inner bolt. Here is where the factory manual is genuinely silent: it tells you to begin with the inner bolt and points you to its rear suspension torque tables for the value, but those tables do not actually list a torque for the trailing-arm-to-carrier mount or for the carrier-to-body fasteners. We are not going to invent a number. Snug these to a sensible, firm tension by feel, and if you want a verified figure, have it checked against current BMW data before you call the job done. The torques the manual does give for the parts you reattach next are in the table at the end.
Anti-seize the body-mount studs and the tops of the subframe mounts before you lift, so the next person (probably you) gets the carrier out cleanly. Jack the carrier back up to the body, start all the body fasteners by hand, then snug them down. Reinstall the springs with their pads, reconnect the lower shock mounts, the sway bar, and the parking brake hardware.
CAUTION: Do not over-anti-seize the self-locking nuts. The factory leaves the nylon-insert locking nuts dry on purpose. Anti-seize belongs on the rusty studs and the subframe mounts, not on the threads of a one-time-use locking nut.
Step 10: Reinstall the Final Drive, Axles, and Set the Torques
Lift the final drive back in and start its mounts. Install the two rear bolts first, then the two fronts, then the rubber-mount nut and bolt with a new self-locking nut. Torque to spec, and note the spec changed across the run.
Reconnect the driveshaft to the diff on your match marks with new self-locking nuts. Reattach the inner CV joints to the drive flanges. Lubricate the inner face of each axle nut, fit new lockplates, and torque the axle nuts and the inner CV joint bolts. The axle nut, like the lug bolts, gets its final torque with the car back on the ground.
| Fastener | Torque |
|---|---|
| Final drive to rear axle carrier (1984-1987) | 110-123 Nm (81-91 ft-lb) |
| Final drive to rear axle carrier (1988-1990) | 80 Nm (59 ft-lb) |
| Final drive rubber mount to body (1984-1987) | 80-87 Nm (59-64 ft-lb) |
| Final drive rubber mount to body (1988-1990) | 87 Nm (64 ft-lb) |
| Driveshaft to final drive (bolt and nut) | 72 Nm (53 ft-lb) |
| Inner CV joint to drive flange (hex bolts) | 58-63 Nm (42-46 ft-lb) |
| Rear axle (hub) nut | 195-210 Nm (144-155 ft-lb) |
| Speedometer pulse sender to final drive | 10 Nm (7 ft-lb) |
| Rear shock lower mount to trailing arm | 72-87 Nm (52-63 ft-lb) |
| Rear shock upper bracket nuts | 22-24 Nm (16-17 ft-lb) |
| Rear sway bar to trailing arm (at ride height) | 22-24 Nm (16-17 ft-lb) |
| Rear brake caliper carrier to trailing arm | 60-67 Nm (44-49 ft-lb) |
| Rear brake hose union | 13-16 Nm (10-12 ft-lb) |
| Rear brake line union | 10-15 Nm (7-11 ft-lb) |
| Wheel lug bolts | 100 +/- 10 Nm (74 +/- 7 ft-lb) |
NOTE: The factory manual gives no published torque for the rear axle carrier-to-body mounting hardware or for the trailing-arm-to-carrier bolts. We are not making one up. Tighten them firmly and evenly, and confirm against current BMW figures if you want a verified number.
Step 11: Bleed the Brakes and Settle the Suspension
Refill and bleed the brake system. You opened it at both rear corners, so bleed at least the rears, working the farthest wheel from the master first. Keep the reservoir topped. If your bleeders were rusty going in, this is where that bites, so be ready to fight a stuck bleeder or replace one.
Set the rear sway bar links and tighten anything spec'd "at normal ride height" with the car back on its wheels and settled. Then do not drive it yet, get a firm pedal first.
NOTE: Do not move the car until you have a high, firm brake pedal that holds under steady pressure. A soft or sinking pedal means air or a leak. Find it before you trust the brakes.
Troubleshooting
The four hex screws by the jacking points strip or will not budge. This is the single hardest part of the job and the reason it earns the "advanced" rating. Penetrating oil ahead of time, a hex socket seated fully, and vise grips on the outside is the method. Never an impact gun, it strips the heads. Heat helps. If one rounds, a hex bit driven in tight or a stud extractor on the bench later is your friend.
A bushing's metal sleeve sheared and a ring is stuck in the body mount. Common. Drill two or three shallow holes into the stuck metal, mark your drill depth so you do not go through, then split the ring with a punch and pick the pieces out. Clean the mount and anti-seize it before the new bushing goes back.
There is still a clunk under throttle after the job. If the clunk tracks with throttle on and off, look at the parts you just disturbed: the final drive bushings and mounts, the driveshaft flex disc (guibo), and the CV joints. A throttle clunk that survives fresh subframe bushings usually lives in the driveline, not in the bushings you just installed. Subframe bushings cure the wander, the driveline cures the clunk, they are different problems that feel similar.
The car still wanders or steps out under acceleration. That is the subframe-bushing symptom, so if it survived the job, recheck that the carrier is fully seated and its fasteners are firm, and that the trailing arm bushings actually got replaced and not just inspected. A bushing that did not press fully home leaves play.
A brake bleeder is seized or snapped during the bleed. Soak it, heat it gently, and back it out with patience, the same fight as anywhere on a thirty-year-old brake. If it is broken off, the caliper likely needs attention, which is its own job. Do not drive on a system you could not properly bleed.
A Note on Doing It Right
This is a heavy, awkward, multi-day job, and the temptation is to cut corners: skip the trailing arm bushings, reuse the locking nuts, beat the bushings instead of pressing them, torch them in place. Resist all of it. You are this deep exactly once every couple of decades, so press the bushings clean, replace the one-time nuts, anti-seize the studs so the next teardown is humane, and bleed the brakes properly. Done right, the back of the car feels planted again and stays that way.
Wrap-Up
You renewed the bushings that hold the rear of the car together, dropped and reset the final drive on its marks and torques, did the trailing arm bushings while you were in there, and bled the brakes you had to open. The wander and the throttle clunk should be gone, and the rear geometry is back where BMW put it. Get a rear alignment once it has settled, especially if you fitted eccentric bushings. For the rest of the chassis, see our BMW E30 Torque Specifications guide.
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