Official: DIY TMS Sub Frame Reinforcement

Originally Posted by aggieE46

No

So why are most people dropping it as well as the instruction say to (besides the oblivious of fire / possible danger). I would assume if you took the necessary safety steps it could stay in. But we all know what assuming can lead to (BOOM)

I don't have first hand experience, but I've seen threads where this was done without dropping the tank. I remember specifically because a well known member commented "oh wow, you did it without removing the tank".

Any chance you can find or remember where you saw that? I would like to confirm it. I went to a shop yesterday and they believe they can do it without dropping the tank but they did not put the car on the rack to confirm. about 750 to do the job is the quote.

I think the tank is really only dropped to deal with the e-brake cable, but I think you can remove the e-brake cable some other way. Wish I had more info, sorry!

Edit: I COULD be wrong. It's happened once or twice before

I have all the subframe bushings, diff mounts, stabilizer bushings, trailing arm bushing and trailing arm ball joints. Ready to tackle this project this long thanksgiving day weekend. Isnt it possible to disconnect the brake calipers and hang them from the shocks instead of disconnecting their hoses so I dont have to bleed?

Also why do I need to remove the Ebrake line at all?

thanks bros

It is easier to remove the E brake line than take it off the brakes.

Yes you have to drop the fuel tank for safety reasons as welding is done right next to it.

I got this done a few weeks ago. Anything over $800 is not a reasonable offer to do the work as a FYI.

Originally Posted by m3dragon

It is easier to remove the E brake line than take it off the brakes.

Yes you have to drop the fuel tank for safety reasons as welding is done right next to it.

I got this done a few weeks ago. Anything over $800 is not a reasonable offer to do the work as a FYI.

I am NOT welding in reinforcements. So can I just remove the brake calipers instead of disconnecting the brake hoses and having to re bleed?

Check M3 forums. I know someone did the none weld install and made a DYI. No clue but my guess is you still need to fully drop everything and re bleed. That is what I remember from their DYI.

Ok Guys SOS. I got the Sub frame out (without disconnecting the brake lines btw). All the subframe bushings and transmission mounts are out but I cannot get the new subframe bushings in!!

I rented a balljoint press from autozone which normally works when I did bushings in the past but the kit deosnt have a press or cup that exactly fits our subframe bushings. I thought ahead of time that I would be able to use this quarter inch thick flat bar and a threaded rod to pull the bushing in but that is failing. I completely man handled the two smaller diff mounts ripping one of them while putting it in. The tear is faint but now that the weak spot for it to fail in the future.. The large main diff mount went in fine.

The first subframe bushing that I put in is also a complete train wreck. The casing is bent outward near the top and rubber is shriveled up. Luckily the inner bushing is still in tact and the bushing is 3/4ths in. Does anyone have any ideas what I can do to finish putting this one in and get the other three in subframe bushings in? I have done plenty of bushing and ball joints in the past and have never had this problem. I am 15 hours in to this project and have only tomorrow to finish..

Run down to Ace hardware, grab a long grade a bolt, and a few nuts and washers. Find or make a plate that will go over the subframe hole. And get a big washer or plate the size of the bushing and use the bolt and nut to push the bushing in.

Originally Posted by choleaoum

Run down to Ace hardware, grab a long grade a bolt, and a few nuts and washers. Find or make a plate that will go over the subframe hole. And get a big washer or plate the size of the bushing and use the bolt and nut to push the bushing in.

The top of the subframe bushing is notched. When you press in a bushing you have to press its metal casing , not its rubber. If I was to merely press the top of the bushing with some sort of flat plate or washer I would be pressing the rubber "up notches" that stick up on either side of the bushing and the bushing's center bolt hole that molded into the rubber both at the same time as they are 2 separate but level pieces. When I press dow as I wrench down the threaded rod, both the bushing "up notches" and the bushing's bolt hole will press about 10-15 MM stretching the bushing beyond its limit in towards the opposite side / into the subframe. I already tried that and ended up really stretching the bushing out of wack. Yes it bounced back that time, but I mangled the rubber a bit and I am afraid to rip it. The notches on the top of the bushing are there for a BMW specific press tool.

Also with doing your method, you have to think that when the bushing is fully pressed in, it actually sticks out the other side about 10mm. So blocking off the side with a flat plate with a threaded rod through it would only get you so far anyways..

You could just get a really big socket from sears to put on it with a 1/2in drive then get some 1/2-13 all thread then put a bolt on each end. That way it presses against the casing and not the rubber.

I used the same method everyone else is describing to install the bushings, but instead of using flat steel plates I used a pipe end cap from home depot, similar to the image below, and drilled a hole in the top center for a threaded steel rod to go through. I don't remember the exact size, but it was pretty much a perfect fit.

Just ordered the bushings and plates from TMS and I'm going to tackle this next week. Thanks for the write up it'll be a lifesaver im sure

Fantastic DIY!

What would a job like this typically cost for an e46 m3? In Socal...

I have all the parts but have been lagging getting this done.

Thank you so much for this write up. We just completed this job successfully. Welded the body and also replaced 2 sub-frame and 1 differential mount while we where at it.
Note; there are 4 extra bolts holding the aluminum bracket to the body you did not describe. Near the differential.

Again, thanks. This helped us (non-car machanics) get this entire job done in about 2.5 days (20-25hours)