A 20 ton press is not enough to remove or install rear trailing arm bushings. To be fair, I probably didn't get a full 20 tons on it since I only had a 12 ton press, and it couldn't handle the full 20 ton load.

Ok, let me back up a little. I'm in the process of rebuilding the rear subframe in my 750iL. This includes all new bushings and other stuff "while I'm there". Knowing there were about 9 bushings to R&R, I decided it was high time to get myself a hydraulic press. The only one I could find locally used (through Craigslist) was a little 12-ton job, which I got for $100. This worked fine for the subframe "bear cans" and the three differential carrier bushings.

But the trailing arms? No way, not even close. So I went to Lowes and got a 20 ton jack on sale for $50. Turns out, the 12 ton press frame gets bent out of shape when you put a 20 ton load on it.

A big problem with the little press was that I couldn't fit the trailing arm inside the frame, which meant I couldn't properly press on the bushing with a support directly under the same end of the trailing arm. Instead, I had to put the other end of the trailing arm on the bottom plate, and I placed the 12 ton jack, under pressure, in between the two ends to keep the trailing arm from collapsing under the load. Here's the setup I ended up with:


But as I said, once I cranked down with the 20 ton jack, the press frame started to get tweaked out of shape, and the bushing didn't budge. Heat didn't help.

What did help was a hole saw and a hack saw - yep cutting was the answer.

Start by cutting off the rubber boot with a knife


Use a 1 1/2 inch hole saw, and start cutting a little. You'll run into a metal ring pretty soon, stop to take it out.


Now you can cut into the rubber.


You can't go all the way with this hole saw, finish the job by cutting from the other side.


Here's the center of the bushing cut out. Yes, this makes a mess.


BTW: wanna know how strong that rubber is? When it became clear cutting out the centers was my only option, I tried to just rip out the center with the press. I applied all the force I could until the frame started bending, and the center did some major movement down. I thought is was coming out, but when I let off the pressure, it snapped back!

Once the centers are out, you can cut the outer sleeve with a hack saw or a sawzall. The trick is to cut through the bushing metal without cutting the trailing arm. It takes patience. If you nick the trailing arm bore, you should file the sharp corners down. I used a chisel to finish getting them out.


I then used a sanding drum on the drill to clean out the trailing arm bores. But when I tried installing a new bushing (using the same setup as the first pic), I could only get it in part way, then it stopped moving and the frame started bending again. Bummer.

So, I'll be taking the arms and bushings to an indy shop to get them on. Well at least I got most of it done myself. In the meantime, I still have my "hydraulic" Craigslist search RSS feed going, maybe a decent-sized press will show up for future jobs :)

Erwin 89 750iL Lowered (a little)

Engine Wolf chips 19 lb, 4-hole (Design 3) fuel injectors PowerFlow Intake Air Filters Royal Purple 20W-50 In process: Custom Cold Air Boxes Interior Phone removed, replaced with cut-to-length dash wood trim on hinge E38 Shifter Knob, Console Plate, and Boot M-Tech 2 M-technic Steering Wheel - air bag deleted E38 Self-Dimming Mirror Audio BMW Business CD Player "CD43" Head Unit Refurbished factory amp w/equalizer Bass blockers (300hz/4ohm) on stock front kick panel speakers Rear deck speakers: Alpine SPS-13C2 5.25" 2 way 175 Watt with bass blockers Subwoofers: 2 JBL GTO804 8" 4-ohm subs Subwoofer install: custom sealed enclosure mounted behind ski bag opening Subwoofer amp: Alpine MRP-M450 400w MONO CD changer relocated to driver's door bottom pocket actuated by bio- mechanical arm controlled by semi-intelligent nut behind the wheel Suspension H&R Lowering Springs (1/2 coil removed from fronts) Koni adjustable front shocks Stock rear shocks (self leveling) Racing Dynamics Stress Bar Stock front sway bar Dinan rear sway bar - 21mm M5 aluminum lower control arms Front tires: 245-40-18 Goodyear Eagle F1 GS-D3 on 8.5" EuroTech rims Rear tires: 275-40-18 Michelin Pilot Sport PS1 on 9.5" EuroTech rims Exterior 25% Side tint 5% Rear tint BMW Mud flaps - rears trimmed to tire width Rear fender lips rolled Smoked side markers Zymol wax Way too many paint chips touched up Brakes Front Rotors: 850CSi, 324 X 30 mm, cross-drilled and slotted Rear Rotors: stock size, cross-drilled and slotted Pads: Hawk Performance Ceramic (may switch to HPS) Stainless steel lines Racing Blue brake fluid

• Trailing Arm Bushings - 20 Tons is not enough (pic) - erwin 2008-03-24 01:34:20 (226 views)
  • Turns out you don't need tonnage, just a $30 tool, and some cold air (pic) (url) - erwin 2008-03-30 22:29:41 (116 views)
  • Thank You - kfister 2008-03-25 22:23:35 (51 views)
    • You're welcome - erwin 2008-03-26 01:30:14 (57 views)
      • BavAuto are OE bushings, sachs or something. - kfister 2008-03-26 03:03:06 (52 views)
        • Yes, I noticed the name difference - erwin 2008-03-26 10:54:23 (41 views)
          • I know bmwautopartsdealer and am surprised they export. (pic) - kfister 2008-03-27 00:16:29 (89 views)
            • I think we have some misunderstandings - erwin 2008-03-27 01:39:06 (46 views)
              • haha confusion. - kfister 2008-03-27 03:57:59 (48 views)
                • Duh ! scroll to the right ! - And - Adjustable dog bones? - erwin 2008-03-27 10:16:12 (54 views)
                  • Dog bones are just heim joints? Sure you could probably roll your own (pic) - kfister 2008-03-28 03:47:57 (82 views)
                    • 750iL Trailing arm bushing dimensions (pic) - erwin 2008-03-30 00:52:54 (72 views)
  • Re: Trailing Arm Bushings - 20 Tons is not enough - geerhed 2008-03-24 07:29:10 (53 views)
    • Um, about 30 deg positive camber, maybe 3.0 inches toe-out - erwin 2008-03-24 10:30:26 (72 views)
      • Re: Um, about 30 deg positive camber, maybe 3.0 inches toe-out - Isiah 90-735il 2008-03-26 04:52:52 (60 views)
        • Thanks, but they seem ok from the outside - should I break them apart? - erwin 2008-03-26 11:33:41 (42 views)
          • Dial indicator - kfister 2008-03-27 00:24:14 (45 views)
            • Thanks, I'll try that. (nt) - erwin 2008-03-27 10:18:18 (41 views)
          • Inner race is a two piece race (nt) - DG740I 3/93 2008-03-26 12:12:35 (43 views)