DIY - Subframe Removal and Bushing Install

[danvitmon]

Hey guys, I'm currently in the process of redoing my subframe bushings, differential bushings, and rear sway bar. I figured I'd make a DIY on it since there's a few write ups but none that are concise and you can follow to a tee. Hopefully this will fill the gap and let others have an easier time. I will update this as I progress through the job. Still currently waiting on some tools and a driveshaft.

I'm having issues with uploading all of the images, here's an imgur folder with all my current photos.
https:// imgur.com/gallery/MQ0mfaF
https:// imgur.com/gallery/lYSG3JL

Skid plate removal

The skid plate is held in with six 16mm bolts and three bolts securing the undertray to the skid plate. I removed the undertray first and then the skid plate. I did not have a transmission undertray but you will want to remove that as well in case you want to lower the transmission and support it.

Complete Exhaust removal

I opted to remove the x pipe first, which consists of 4 E12 torx bolts with 14mm lock nuts on the back. Disconnect the 4 O2 sensors plugs, one of which is behind a little cover held in with two T25 bolts. Unbolt the two clamps holding the muffler to the x pipe, and try to pry the x pipe loose, while still making sure the header connections are still holding the x pipe on. I completely removed the bolts but you can leave a bolt in just to make sure it doesn't fall out. I then removed the four 13mm bolts holding the middle exhaust support, and carefully dropped the x pipe. Move the x pipe out of the way so you can have room for the muffler.

I have a stock muffler which might bolt up different compared to some others but the process should be the same relatively. I removed the two 18mm nuts holding the connecting pipes up, and jiggled the hanger slightly off of the diff bolts. I removed the two 8mm bolts holding the bottom of the bumper to the exhaust support, and then removed the two E10 torx bolts holding in the back hanger. I then removed the four 13mm nuts holding the side hangers in place and carefully places the muffler on myself and wiggled out from under the car.

Heat shielding removal

The two heat shields are held in place with a variety of 8mm, 10mm and I think 13mm bolts/screws. The rear heat shield came off first with a few 8mm screws and some 10mm sheet metal nuts. The front heat shield came off similarly. You will have to slightly bend your heat shields to get them out from the undertray sandwich they're in. Or just be careful about it.

Driveshaft removal

I opted to completely remove the driveshaft since I'm getting a new one anyways, but you might be able to get away with just disconnecting the CV to the diff, and moving it out of the way. Regardless, I supported the trans with a stand, and removed the four 13mm bolts for trans brace/mount, and removed the four 13mm nuts for the trans bushings. With the brace gone, you have a lot more access to the six 18mm bolts/nuts. These are incredibly tight, so either use a breaker bar or a big impact to get them loose. You can probably remove just the three holding in the driveshaft to the guibo, but again I'm getting a new one so I just removed it all. Then remove the six E12 or E14 bolts for the CV to the diff. The CV will not pop out easily, I had to get a prybar into one of the grooves cut into the CV to pop it out. Then remove the two 13mm bolts holding the center support bearing in, and drop the driveshaft out.

Half-shaft disconnect

Disconnect the two axles from the differential so it's easier to remove the diff from the subframe when you drop it all. You could probably remove the diff completely and make it easier to drop the subframe, but I opted to leave it in. The two axles are held in with six E12 or E14 bolts that are torqued super high, so either use a breaker bar or an impact. The e brake should still be connected so use that or put a screw driver in between the cooling slots of the rotor so the screwdriver hits the caliper when you try to spin it. Disconnect the half shafts after removing the six bolts on both sides.

Rear fender liner removal

The rear fender liners are held in with some 8mm bolts and 10mm plastic nuts. There are two 8mm screws on the bottom of the car, make sure to take those out. The easiest way to remove these is to try and clear the studs first and then focus on removing the liner.

Rear sensor disconnects

The rear sensor plugs are hidden behind the liner. The passenger side has two plugs, one for the wheel speed sensor and one for the pad wear sensor. Disconnect both. The driver side has a sensor for the wheel speed and one for the ride height. Disconnect both. You will have to wiggle the ride height sensor out of the way of the subframe so it doesn't catch when you drop it.

Brake line disconnect

The brake lines are easiest to disconnect at the first rubber connection, on the driver side just in between the fuel tank and the subframe. The flare nut is an 11mm, be careful to not strip it. Disconnect both lines and plug the rubber line with something, just to minimize fluid loss.

E brake cable disconnect

The e brake cables can be removed a different way but I did this. Remove the brake caliper assembly, two 16mm bolts. Remove the rotors, two 5mm or 6mm allen bolts. Remove the upper and lower spring holding the e brake shoes together, make sure to do this first as it's a PITA to do it with the shoes loose. Then remove the 5mm quarter turn Allen bolt holding in the shoe on either side. Then remove the little piece that's attached to the e brake cable. Remove the 5mm bolt holding in the e brake cable clip from the back of the wheel carrier. Then pull out the e brake cable on both sides.

Subframe removal prep

Disconnect the shock either at the bottom or the top. I did it at the bottom. A single 18mm bolt holds the shock in. There are two air deflectors on the bottom of the car that block access to a bolt you need to remove. These deflectors are held in with plastic push pins and T27 plastic bolts. Remove or lower the deflectors so you can get access to the two 16mm bolts on either side that connect the fuel tank strap to the subframe bushings. Now you can start getting ready for the drop.

Subframe removal - Bring a friend or two

I did this myself which made it a lot more complicated, but it's easy with a friend or two. The subframe is held in with two E18 torx bolts at the back of the car, and two E18 torx bolts toward the front of the car. Have the jack support the diff/subframe and use a breaker bar or impact on the bolts and remove them. I put jack stands under the control arms to support it on the sides. Then lower the jack and take care of the front bushings since they have holes for the dowels on the chassis. I opted to lower the subframe and then go on the left side and lift up the carrier by hand, lower the jack stand a bit and then go to the other side to do the same thing. I would then lower the jack a bit more and just rinse and repeat until I had the dust shields/subframe clear of the lowest part of the car. I had already removed the jackstands by that point and started to balance the subframe on the jack. I then pulled the subframe assembly out carefully making sure it wouldn't drop. Now you can put the subframe in a safe place and either put jack stands underneath the wheel hub or leave it as is. I had to remove the diff so I put the subframe on stands and removed the front two 18mm bolts holding the diff in, and the single 21mm bolt and nut at the back. Support the subframe when you're dropping the diff, otherwise stuff will start falling.

Subframe bushing removal - Large M18 Impact Recommended

Removing the bushings isn't too difficult, so long as you have the right tools. I bought and used this tool from Forsvara Engineering, https://forsvaraengineering.com/shop...bushing-puller I talked to the owner about a diff bushing tool since he doesn't have one, and he said he is working on it and should be able to get some prototypes built soon. I gave him some measurements to aid in the tool making process. The tool itself was easy to use and well made. Make sure to grease the threaded rod with something, I used LiquiMoly's molybdenum grease. The two flanged nuts are 19mm, and make sure to buy a deep or extra deep socket if you're gonna use a ratchet/breaker bar. For the large bushings that are at the BACK of the car, near the muffler, you have to make sure to position the large cup just over the bushing, the tolerance is very tight and if you place it incorrectly, you will just be pressing against yourself. You won't actually be pressing the bushing out. Once you position the tool correctly according to the diagram/pictures Forsvara provides, start tightening the nut and pushing the bushing out. An impact speeds the process up significantly. Now for the front bushings that are next the the driveshaft CV, you will have to break off the little aluminum lips of the bushing at the top. The reason is because the flange adapter that Forsvara provides is actually smaller than the outer edge of the bushing, and you will not be able to get the flange over it. By breaking off the aluminum pieces, you are able to place the adapter/tanged washer on it without issue. The little pieces break off fairly easy with a flathead screwdriver, prybar or a chisel. Once you break them off, position the tool according to the diagram, and start tightening the remove the bushing. Once you have all the bushings out, clean the insides where the bushing used to sit, with either scotch-brite or a cleaner and towel.

Differential bushing removal - Large M18 Impact Recommended

I bought these tools for the differential bushings - DAYUAN 27pc Universal Press and Pull Sleeve Kit Bush Bearing Removal Insertion Tool Set https://a.co/d/4qxwvOA These bushings are much easier to remove than the subframe bushings, but still take care to not damage the inner races or the subframe. For the front two bushings, I used the 48/38 inner cup to press on the bushing, and the 60/50 cup to accept the bushing. I then used the M12 thread rod/nut combo, which uses 19mm nuts. I used a ratcheting wrench and normal wrench for this. I placed the pressing up on the front side of the subframe, and the accepting cup on the back side of the subframe. You might be able to reverse the positioning. Then insert the threaded rod, attach and tighten the nuts and press the bushing out. I repeated this for the other bushing. For the single bushing at the back of the subframe, I believe I used the same exact method/cups/threaded rod. Repeat the process on that bushing as well. Clean the inside races as well once you get them pressed out.

Differential bushing install

Installing the differential bushings is the opposite of removal. I used Millway delrin bushes because I didn't want the risk of issues with aluminum ones, but I also didn't want to use polyurethane ones and run the risk of deformation over time. Millway makes great pieces and they're priced well. Use the same cups for install, and just repeat the opposite of the removal process. The bushings come with no instructions, but I figured out that for the front two, the lip goes toward the back of the subframe facing the diff, and the front of the bushing should be parallel with the edge of the metal, with the little inside piece jutting out slightly. Pictures are in the imgur for visualization. The rear bushing can fit both ways, I decided to have the Millway logo facing away from the diff. Press the bushing in to be parallel with the subframe metal.

Subframe bushing install - Large M18 Impact RECOMMENDED, if not NECESSARY

This is the worst part of the job. I used Bimmerworld Solid Aluminum bushings, in hind sight I would go with delrin or poly because this was a struggle. The rear bushings went in fairly easily, again, just the opposite of the removal. Follow the diagram Forsvara provides and you won't have any issues. Make sure to not press the bushing in any further than when it bottoms out, otherwise you WILL compress the subframe. I accidentally compressed one side a bit further than just bottoming out. I know because one side measures 3mm shorter than the other. Don't make my mistake, it shouldn't cause any issues, but just don't go past bottoming out. The front bushings were a nightmare without an M18 impact. I used a 4ft breaker bar on the front bushings, after around 3hrs of struggling, I still had around 16mm left to press in. I was applying roughly 400-500ftlbs, at a 1/4 turn at a time. A friend came over with the big boy M18 impact, and it did the 16mm in 15 seconds. I froze my bushings before install which helped a little but after 3hrs it didn't matter. Once you get all the bushings in, get a drink and relax.

Rear sway bar removal and install

The rear sway bar is attached with two end links utilizing two 16mm nuts, and two bushings held down with brackets with four 6mm allen bolts. Remove the four allens and brackets. For the end links, you either have to have a super thin wrench to hold down the link from spinning, or do what I did and get vice grips on it. Make sure the grips have a good hold so you don't mar the link. Remove them and remove the entire sway bar. I went with a Hotchkis bar, which came with the bushings, brackets and washers for the brackets. I installed the sway bar at it's softest setting, and tried to position the sway bar as far away from the CV axle boot as possible. There are stories of the boots being torn due to factory end links with the larger sway bar, so just take note of that and keep an eye on it. The sway bar brackets are 16ftlbs, and the end links are 42ftlbs to the sway bar.

Clean as much as you can

I like to have a clean car so I can see if any leaks develop or damage occurs. Working on clean stuff is also much nicer, and it's incredibly satisfying to make a dirty underside, clean. I would suggest you clean the subframe, diff, and underside because you will likely not have this opportunity again.

Diff install

I installed the diff before installing the subframe for ease of install and to have a nice platform to jack the subframe up with. I had the subframe as high as it could go on the jack stands, and put the entire diff on my jack, and jacked the diff up into its area. Then I put the large 21mm bolt through in the back for support, and then just barely threaded in the front 18mm bolts. I would suggest red loctite for these bolts, since the 18mm get torqued to 74ftlbs, and the rear gets torqued to 122ftlbs. Then connect the axles to the diff and just hand tighten the E14 bolts so everything is supported.

Subframe install

This was challenging with one person, get a friend if you can. Jack the subframe up with the iron case of the diff, and slowly/carefully move the subframe underneath the car. Put the springs/rubber spring pads into the spring arm. I had to compress the shocks a little to get them to go past the top camber arm. Then position the subframe assembly approximately where it should go, trying to line up the holes of the subframe bushings and the chassis threads. When I had the subframe where I was happy with it, I put jack stands on both sides underneath the spring arm. I jacked the subframe up 2-3 pumps, then slowly would raise the jack stand one click on one side, and raise the other side jack stand one click up as well. Do as many clicks up at a time as you are comfortable, but it's kind of sketchy. The biggest issue is that when you jack the subframe up with the jack, the subframe will want to tilt backwards, so you have to be careful to keep the jack stands supporting it, otherwise it can fall back on you. Eventually, you will get to the point of trying to get the front bushings into the locating holes of the chassis. Once you get those in, bolt the v brace in with the E18 torx bolts and the two 16mm bolts. Bolt everything up hand tight and make sure not to cross thread anything. The v brace has some movement when you bolt it up hand tight, and keep it that way until you can be sure to get the holes where the exhaust middle support and v brace bolt holes line up. Then jack up the subframe some more so you can get the back two E18 bolts in with the large washers. Hook up the brake lines with the 11mm flare lines. Once you get everything in, start tightening the four E18 torx bolts to the chassis and get the subframe flat against the chassis. The subframe bolts are torqued to 80ftlbs. Get the v brace holes lined up where the exhaust middle support bolts up, once they're lined up, get the v brace 16mm bolts torqued to 35ftlbs and 90 degrees.

Brake system install

Get the handbrake cable routed through the iron hub, and hook the metal clip/swingy thing around the cable. Install the 5mm bolt with the holder clip for the ebrake cable around the back of the hub. Then put both ebrake shoes on with the 5mm quarter turn bolt. You can put some grease on the little metal contact points of the backing plate where the shoes ride on. Then put the adjuster in on top, and install the springs on top and bottom. Install the brake rotor on with the 6mm set bolts, and make sure the ebrake is adjusted properly. Install the brake calipers with the 16mm bolts, torqued to 48ftlbs. Hook up the ebrake cables to the little bracket on the subframe. Bleed the brakes with either the motive pump, or bring a person over to pump the pedal.

Sensor and fender liner install

Connect the ride height sensor and wheel speed sensor on the driver side, and the wheel speed sensor and brake pad wear sensor on the passenger side. The fender liners go in easily, just be patient since the studs will be weird to work around, but with enough finagling the liner will just plop in. Bolt up all the little 8mm screws and 10mm plastic nuts.

Driveshaft and CV Axle install

Put the ebrake on and torque the CV Axle E14 bolts to 89ftlbs. Get the driveshaft in and torque the E12 or E14 bolts to 15ftlbs and 90 degrees. Get the front bolted up to the guibo and torque to 41ftlbs and 90 degrees. Then bolt up the CSB and torque the two 13mm bolts to 15ftlbs.

Transmission and final proceedings

Support the transmission with your body or a jack, and bolt up the transmission bracket to the chassis, lining up the holes of the rubber/solid mounts to the bracket. Torque the four 13mm bolts to 14ftlbs, and the four 13mm nuts to 14ftlbs. Bolt up the heat shielding pieces, with various 8mm screws, 10mm sheet metal nuts, and some 13mm bolts. Get the x pipe in on the front header connections, and support the x pipe by bolting up the middle support with the four 13mm long bolts. Then bolt up the x pipe with the E12 bolts and 14mm nuts to the header connections, applying equal pressure to both sides to get a good seal. Support the muffler and get it positioned correctly. Then bolt up the two 18mm nuts for the middle muffler hangers, and connect the two pipes with the 13mm clamps. Bolt up the four 13mm nuts for the rear exhaust hangers, the two E10 torx bolts for the rear hanger, and finally the two 8mm bolts for the exhaust bracket to the bumper. Bolt up the undertrays, six 16mm bolts for the large reinforcement tray, and whatever you need for whichever front undertray you are using. Then get the transmission undertray in with the various 8mm screws, 10mm nuts, and some 10mm bolts.

BLEED THE REAR BRAKES! Don't forget to bleed the brakes and add the correct amount of fluid. I take care of a few spec e46s and some 992 cup cars, we always keep fluid around the middle or 3/4 level. If you put it at the tippity top, the fluid will expand and seep through the seal.

Give yourself a pat on the back, and take a well deserved shower. You saved 1.5-3k of labor costs, go out and enjoy the car!

[Thumbie]

Great write up so far!

[jvictormp]

I'm impressed it worked out with the threaded tools. I had to hydro-press mine.

Btw, nice write up!

[danvitmon]

Originally Posted by jvictormp

I'm impressed it worked out with the threaded tools. I had to hydro-press mine.

Btw, nice write up!

I am as surprised as you! I was on the verge of taking the subframe to a shop to get the bushings pressed in, but a friend suggested I use his M18 impact and it went in without issue. Thanks for the kind words!

[Scandinavian_Flick]

Originally Posted by jvictormp

I'm impressed it worked out with the threaded tools. I had to hydro-press mine.

Surprised here too, when I took mine out I elected just to burn them out, and then a press was pretty much mandatory for the solid bushings that went back in.

[danvitmon]

Originally Posted by Scandinavian_Flick

Surprised here too, when I took mine out I elected just to burn them out, and then a press was pretty much mandatory for the solid bushings that went back in.

I wasn't able to get the subframe bushings in with just using a breaker bar, I had to ask to borrow a friends big boy M18 impact, then they went in super easy.

[tdott]

Originally Posted by danvitmon

The front bushings were a nightmare without an M18 impact. I used a 4ft breaker bar on the front bushings, after around 3hrs of struggling, I still had around 16mm left to press in. I was applying roughly 400-500ftlbs, at a 1/4 turn at a time. A friend came over with the big boy M18 impact, and it did the 16mm in 15 seconds. I froze my bushings before install which helped a little but after 3hrs it didn't matter. Once you get all the bushings in, get a drink and relax.

Good work! I am surprised you didn't damage the threaded rod or tool applying that much force?

Do you have any pictures of how it looked when you had the tool setup to remove/install the bushings?

[danvitmon]

Originally Posted by tdott

Good work! I am surprised you didn't damage the threaded rod or tool applying that much force?

Do you have any pictures of how it looked when you had the tool setup to remove/install the bushings?

I do not, but in one of the pictures with the subframe out, you can see I had my helmet and gloves out, and in the bottom left of it, you can kinda see how I had the tool (partially disassembled but with everything in order)