How not to replace BMW F10 Subframe Bushings…

This video is a bit of a warning, if you are going to attempt to replace your F10 5 series rear subframe bushings, don’t do it like this. In fact, let me start with how you should do it. First, buy the right press tool kit. You’ll need a 98mm cup to press the bushings through, and something like a 102mm cup to rest on the subframe for the bushing to slide into. Second, while in theory you don’t absolutely have to, I would personally recommend just removing the subframe and using a hydraulic press to swap them. You can do it on the car, but you’ll need to press the front to upwards out of the subframe which might be difficult space wise. Alternatively, this might be the sort of job you’ll want your local garage to do. Trust me, it’s not worth it.

How do I know it’s not worth it? I just spent two days under the back of one fighting to badly install one new bushing. Yeah… And it all started off so well! We started with getting the subframe loose which meant lowering the exhaust. We removed the central cross brace, removed the nuts and bolts holding the backbox mounts on and used a pry bar to pull the more central hanger off of the exhaust mount. We used a jack stand to support it, which gave us enough clearance to get at the 21mm bolts holding the subframe on.

For the two front mounts, we had to remove the plastic trim pieces, then the two 16mm bolts holding the support plates on, then we loosened the four 21mm bolts to allow the subframe to drop down. We had the body on jackstands and the jack on the centre of the diff, so we could both support the subframe and drop it down to any height we wanted. We did have a press kit, sadly none of the plates properly fit as these are bigger than most bushings around.

We figured that since these were just plastic, they would drop out fairly easily. We were so wrong. We used a 102mm (4”) hole saw as the receiver cup which does fit fine, but despite our best efforts we couldn’t get it to budge at all. We tried using a blow torch to heat the aluminium, to no success. Really, we tried everything. At some point we realised we had likely damaged the bushing too much to call it quits and went “full send”.

Out came the drills, saws, chisels, punches, pry bars, we went and bought a reciprocating saw, and after what was probably 3 total hours of fighting it, we finally figured out the technique of cutting a chunk out of the plastic sidewall then using the chisel to snap it out, then use vice grips to drag it kicking and screaming out of there.

Much to our surprise, the inside bore of the subframe mount was knurled – somewhat ribbed – I assume to give better grip on the plastic walls, but mostly gave space for the aluminium to corrode like mad. If anyone who isn’t a complete moron like me knows if this is standard and why, please do drop a comment below because I would love to learn more about that. Anyway, we cleaned out the bore, then tried to get the new bushing in. Cue even more frustration, anger and pain.

Unsurprisingly, the new bushing isn’t exactly easy to push in. We figured we could use a mallet to get it in place, then use the jack to press it in place. Yeah, no. First off, the bushing is so much bigger than the hole that it won’t even seat itself. Second, even when you do get it even slightly in, you need to put more force than the weight of the entire back of the car with two tool boxes and two lads in the boot combined. So, the floor jack just lifts the car, using the bushing as a jacking point. Seriously!

The only success we had was going back to the press kit, and actually using the mounting plate that the bushing has under it as our press plate. That’s what let us get it pretty much all the way in. That and liberal application of WD40. It’s safe to say we will be paying a garage to do the other three as soon as possible.

So, let this be a lesson both to you and my future self. Anything to do with pressing bushings requires a hydraulic press, the right cups, and about three times more time than you expect it will. With the right tools I’m sure it wouldn’t have been as much of a problem, but that’s always the case and we have yet to learn that lesson. One day, I hope…