I just recently purchased a 1997 M3/4/5. I am a longtime BMW owner (E30's, E46's, E90) , but I've never owned any E36's. The M3 I purchased runs well , but I can tell that some of the rear suspension components need to be refreshed. (It's not too surprising, because the car has 206,000 miles on it.)
Here's my question: Should I just bite the bullet and drop the subframe, so that I have access to all the bushings (i.e. subframe, differential, control arms, etc.) or should I just start changing the control arm bushings first and see what happens? How often do the subframe bushings fail?
Thanks for your help.
Here's what you will likely want to do unless the previous owner can confirm any of this has been done already. Being someone who did part of this early on and is now having to go back in and do everything else, I'd strongly suggest doing it completely once if possible. You'll probably have to have the suspension off the car for a weekend or two, but it'll allow you to get everything taken care of at once.
- Replace all shocks unless you can confirm that they've been replaced in the last 75K miles or so
- Inspect springs and replace if desired (like if they're aftermarket and you want to go back to stock height or whatever)
- Now's the time to do camber plates, height adjusters, or any sort of coilover kit if you want to
- Replace rear shock mounts with reinforced aftermarket mounts (GC, Rogue, etc...)
- Replace rear trailing arm bushings (RTAB's) with OEM bushings with limiters
- Replace diff bushings/mounts with OEM or poly (NVH preference)
- Replace rear subframe bushings with OEM or poly (NVH preference)
- Replace rear sway bar bushings (or upgrade your sway bars)
- Replace upper and lower rear ball joints with OEM (lemforder) - there's two on each side for four total, all the same part number
- Replace inner bushings for upper and lower control arms with OEM (lemforder)
- Inspect rear wheel bearings and replace if necessary
- While you have your rear subframe out, weld in swaybar tab reinforcements (optional)
- Weld in RTAB pocket reinforcements (optional)
- Replace front control arm bushings (FCAB's) with OEM or poly (NVH preference)
- Replace motor mounts with OEM or poly (NVH preference)
- Replace transmission mounts with OEM or poly (NVH preference)
- Replace front control arms, or press new OEM (lemforder) ball joints into existing arms (two per arm)
- Replace front sway bar bushings (or upgrade your sway bars)
- Replace tie rod ends (or upgrade the whole steering rack if desired)
- Inspect front wheel bearings and replace if necessary
- While you have your front subframe accessible or out, weld in motor mount reinforcements (optional)
- If not using camber plates, install front shock tower reinforcement plates (they sandwich between the strut and tower)
That's everything off the top of my head. You don't necessarily need to do every single thing on this list, but I can be fairly certain that all these items are probably heavily worn if original on your car. Replacing each will incrementally tighten up slop in your suspension. If you do everything, it will probably handle better than it did from the factory.
Last edited by TostitoBandito; 11-15-2017 at 10:47 AM.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
I understand the "Replace Everything" theory of maintenance. I use that guideline regularly.
However, considering the pain of dropping the subframe, are there any alternatives? For example, if the RTAB's always go first, can I just look at those and judge the condition of the rest of the bushings?
I would change the RTABs (shims are cheap too), RSMs, and rear shocks - can be done in a day without dropping anything and should greatly improve ride quality. Then see how the car actually drives. If you are happy with it, then that's fine. You can plan a more thorough overhaul or just keep driving.
Don't understand this forum's obsession with taking high mileage cars and telling new owners to spend weeks and thousands refreshing every part (not just tostito you see it in many threads). The previous owner obviously had no problem driving it the way it was you shouldn't either if you are happy with it.
Can you drop the subframe with the car on jackstands and only using a floor jack to lower the subframe?
Absolutely. There's a couple ways you can do it, depending on what you want to disconnect and where. Procedure is the same as removing the diff more or less, except you leave the diff bolted to the subframe, put the jack under the diff, and lower away once the CV joints, drive shaft, control arms, and subframe bolts are disconnected.
Having a helper is nice to get everything lined up right while jacking it back into position.
And to echo what others said, no you don't need to do everything I listed. The more critical and easier items are the RTAB's and RSM's, and probably all four shocks. However, as I said if you're going to drop the subframe for any reason it really makes sense to look at a lot of the other smaller wear items. The parts aren't very expensive and it's the simplest time to do them in terms of labor. You can also do the outer ball joints at a later date without taking everything off the car (just need to disconnect control arms and maybe brakes/dust shield).
The only things that really require the rear subframe being out are any welded reinforcements and subframe bushings. Everything else you can do with the subframe in place, though difficulty may vary.
The front end is somewhat simpler. The only PITA item is the control arm ball joints. Everything else is pretty straightforward as long as you have a way to support the engine while you swap out motor mounts.
Last edited by TostitoBandito; 11-16-2017 at 11:16 AM.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
This forum is mostly full of enthusiasts, it should be no surprise. That being said, we don't know that the previous owner was happy with the way it rode or if it's just what he told the potential buyers in order to sell it. Besides, even if he was happy with the way it rode it doesn't mean that it felt the way it would/should have.
All rubber on a 20-year old car with 200k probably should be replaced, but some, like the guibo, CSB, and diff bushing, end up being cheaper to replace than waiting for them to fail.
The rear subframe is really not that hard to drop. It's a little tricky to balance and line it back up with a floor jack, but it can be done with one person. When I did it a couple months ago, my only hold-up were corroded brake line fittings that would not come apart and had to be replaced (my cheap line wrench broke and I was pressed for time so I had to cut the line and fix it later).
Hi everyone,
I'm reporting back on this almost two year old post. Here's what I did to the suspension of the above 1997 M3(each line below was an individual repair event):
New rear shock absorbers- much nicer ride and control
New front control arm bushings- better stability
New RTAB- car feels tighter
New steering rag joint- steering feels tighter
New differential and rear subframe bushings- this really was the final touch. It feels like a new car now. It was a pain to accomplish, but worth it.
Thanks for everyone's help.
I just finished doing the rear control arm ball joints and bushings at 240k. They were utterly shot. Like you, I'd done everything else you listed (and more) over time.
Not that you need a new project, but these will make a very tangible difference in how the car feels. The car will really feel like a new car once that last piece of the puzzle is finished.
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
I checked the rear control arm ball joints when I had it apart. I couldn't see or feel anything wrong with them. Were yours visibly loose before you replaced them?
Only this last time.
I'd noticed a lot of rattle in the suspension over rough pavement for a long time. Other than that, everything generally seemed ok, so I just chalked it up to being an old car.
Then I went through a set of tires in six months. That was the last straw.
This has completely fixed the rattle, as well as a couple of other problems (car sat crazy low, camber and toe were hard or impossible to get anywhere close to right). I have no doubt I'll get
A ball joint should never get so bad it's actually loose. You shouldn't be able to move them by hand. I could reach under the car and twist the control arms back and forth. One of mine was so bad I could clunk it back and forth, two were loose enough to move by hand, and one was so bad it was binding.
You've got to be around my same mileage if you were at 206k two years ago. I don't know if they're causing you problems or not like mine were causing me, but I guarantee they're shot.
And outer bolt (a camber bolt) was completely rusted to the ball joint - I had to cut the head off to get the arm off. I had to use a combination of the home made press tool, the O'Reilly's giant C-clamp tool, and the 36mm socket for the tranny output shaft nut as the actual arbor to press everything in. The whole operation was a metric crap ton of work. I'd rather replace my clutch than have to do that again.
But it was absolutely worth it.
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