Seized Control Arm Bolts

I think the most talked-about impediment to suspension renovation is the seizing of control arm bolts to their bushing inner sleeves. For some of the bolts the bond is so tight that, upon attempting to free the bolts, their heads snap off. For others the bushing rubber shears from the inner sleeve; upon applying a wrench, the bolt and inner sleeve spin as one. From the Usenet archives, the problem occurs not just in Hondas but in many vehicle makes. People write of trying Easy-Outs (these in turn also snap off); heat and/or the penetrating oil PB Blaster (neither are sufficient); hack saws and electric drills (you will saw and drill for hours, because the suspension bolts and bushing sleeves are very hard steel). I experienced all of these in 2004 when replacing a rear spring/shock absorber assembly on my 91 Civic. It was so exhausting, and also mostly futile, that I did not touch my suspension again for over a year. I shook my head every time I thought about it. In 2006, I noticed my Civic's driver side was lower than the passenger side by about 3/4-inch. Also tire wear was uneven on the front passenger side. I checked the condition of the front suspension and found the rubber in the control arms' bushings badly cracked. I decided to see if I could replace the bushings. Naturally I ran into seized bolts. I researched so as to avoid the 2004 mess. Here is the method I developed for removing a seized control arm bolt. The first time I tried this method, it took a few hours going very slowly. For subsequent seized bolts I needed only about 30 minutes per bolt. The learning curve is steep.

diegrinder2.jpg
Air Die Grinder, Cut Bolts

  • 2007? Update: Use a DeWalt Impact wrench, first tightening, then untightening.
  • July 2006: One tool is common to all other posts that report success in removing the bolts: A compressed air driven grinder (die or angle). I already owned a small shop air compressor (2 HP, 5 CFM at 90 PSI, 8 gallon tank). I bought an air die grinder for $13 at Checker Auto Parts (rated at 20,000 RPM and 3 CFM at 90 PSI); a 1/16-inch thick, 3-inch diameter "metal cutoff wheel" and 1/4-inch shank arbor, packaged as a set from Lowe's for $6; air tool oil at Lowe's for $2; and a 1/32-inch thick, 4-inch diameter metal cutoff wheel at True Value Hardware. The smaller thickness cutoff wheel cuts more quickly. The larger diameter permits getting the tool into tighter spaces. Make sure the air die grinder RPM rating is lower than the wheel rating; grinding wheels are known to explode if rotated higher than their rating. Be aware that a "cutoff wheel" differs from a "grinding wheel." The wheels will be clearly marked. You want the "cutoff wheel." (Thanks to rec.autos.tech for many of these warnings.)
  • I went very slowly, since it had been many years since I had had any type of air grinder in my hand. Also the space is tight. I tried to use the grinder as little as possible to minimize risk to life, limb and property.
  • Have safety glasses, face covering and leather gloves handy. The safety glasses should fully cover the eye area, or else fine metal dust will get in your eyes. If in an enclosed space like a garage, wear a dust mask. Don these when using the air grinder. Make sure none of your body is in the plane of the cutoff wheel when operating the air grinder. Chips from the cutoff wheel can fly off at over 150 mph.
  • If working on the front control arms, drive the front of the car onto auto ramps. This gives more space to work.
  • Do not work beneath a hot engine. For one thing, sparks will fly while cutting. A risk of fire exists.
  • A few days in advance, spray the penetrating oil PB Blaster onto where the bolt head touches the bracket; the threads at the end of the bolt; and in between. Tap all around with a small hammer. Use one of those red straws that directs spray. Drive the car (this puts weight on the bolts and I think may help the PB Blaster soak in.) I am convinced that PB Blaster makes a difference.
  • For some control arm bolts, the bolt heads may shear off. Avoid this. If you try to unscrew the bolt and it does not seem to come free, but instead the resistance seems to change suddenly, stop. The head is about to shear off. Working with an intact bolt head is easier.
  • For control arm bolts that seize to the inner sleeve of the bushing and just spin in place: Unscrew the bolt until its threads no longer engage with the (fixed) nut. This will expose a fair amount of the bushing inner sleeve. If years have passed since the bolts were removed, this will take some effort. Where possible do this a few days in advance, just to break the bolt free of any seizing in the nut.
  • Attach the cutoff wheel to the air grinder.
  • In the two places between the bracket and control arm, with the air die grinder and the 4-inch diameter, 1/32-inch thick cutoff wheel, cut through the bushing inner sleeve until you see the bolt outline. You can cut as much as maybe halfway through the bolt and still be fine, from what I have seen. Cut so that the direction of the cutoff wheel tends to apply torque that loosens the bolt. Cut in maybe three stages. The sleeve is about 1/8-inch thick, so not that much cutting is necessary. I think I usually had to cut only about four minutes per bolt altogether. Sparks fly, of course.
  • Spray PB Blaster into the two cuts. Capillary action should cause the PB Blaster to soak readily into the cuts. Tap. Wait anywhere from a few minutes to maybe an hour to let the PB Blaster work. Re-apply the PB Blaster and tap a few times more.
  • Cut further. Stop cutting now and then and tap the exposed bolt hard via the grooves you have cut in the sleeve. Tap on both bolt ends. For a control arm bolt that advances into and out of a nut, but otherwise spins, apply a wrench and advance (tighten) the bolt back into the nut a few times. Eventually by looking into the new grooves in the sleeve, you will see the bolt moving relative to the sleeve. For some of the bolts I could hear little popping noises, too, as I applied torque, suggesting the bolt was breaking free.
  • To remove the bolt fully, you may want to support the control arm with a jack. I managed to strip the threads of one bolt while removing it, because I did not line things up carefully. But I also knew I had a spare bolt.
  • Try not to cut all the way through the sleeve and bolt. I think overall removal is easier with an intact bolt. The bolt head in particular permits one to maneuver the other end of the bolt, but of course only as long as they are still attached. Nonetheless, in the worst case, cut all the way through at the two points such that you can swing the control arm free from the bracket. Hopefully you then have enough stub remaining at the bolt's threaded end to grasp it with vice grips and unscrew it. If not, try an air chisel on the stub, in the direction that loosens it. In the one instance where I had to cut all the way through, the stub was easy to turn with pliers.
  • On car ramps while working on the front control arms, I protected the front wheels with blocks of wood. A piece of cutoff wheel flying off and penetrating the tire would be curtains for you. Take breaks. Stay rested. Be alert. Think always: Is there a safer way to do this?
  • For the front, once you have freed a seized bolt you might want to drive the car down the ramps and put the appropriate side on a jackstand. The ramps seem more secure to me for heavy torquing.
  • Re-inserting a new bolt should be done with the appropriate side on a jackstand. This allows adjustment of the hub position, which in turn allows easier adjustment of the control arm position. Use a crowbar on the control arm, and/or insert a screwdriver into the bolt hole and bushing, to help things along as needed. One can pull up or down on the control arm and pry with the crowbar and screwdriver until the bolt can be inserted into the bushing again. Re-installing the bolt is a little tricky but not aggravatingly so, if one has done it a few times.
  • Note that the mechanism of freeing the bolt here may simply be a lot of vibration, heat and the penetrating oil. If cutting is extensive, frequently check the status of the bolt in the sleeve. It may suddenly come free.
  • Frozen bolt count for my 1991 Civic: two front lower control arm inboards; two rear lower control arm outboards; one rear coil/shock assembly; two rear upper control arms; one rear compensator arm adjusting. In other words, of 16 bushings, 50% had bolts seized to the bushing inner sleeves.



Lessons Learned
  1. For a younger car driven in a non-corrosive environment, either a 12-ton shop press or the sockets-bolt-nut-washer method might work fine to remove old bushings. This is not necessarily so for an older car driven in a corrosive environment such as the Midwest or Northern United States. Site overboost.com for one, used to have an article about how a 12-ton shop press was not enough for bushing removal.
  2. A 12-ton shop press would likely successfully and easily install new bushings. I do not think a 2-ton press would always be enough, based on my experience and calculations and reading about others trying 2-ton presses.
  3. Even if one goes with the shop press, one will have to buy the sockets or other bushing press accessories.
  4. Based on my calculations of the tons of force required, I have doubts about the wisdom of using any hammer to beat bushings into an older control arm already scuffed up from bushing removal. One has to possess a great deal of upper body strength and a lot of endurance, not be susceptible to heart attacks, etc. I think that the force the two screw methods (sockets-bolt-nut-washers-etc. and puller) offer is in fact much higher than that achieved by blows with a huge hammer. Applying hammer blows also risks the integrity of the bushing and control arm. Strongly consider using the amazing leverage of one or both of these screw methods in place of a hammer.
  5. Snap-on Tools sells a puller with a 3/4-inch diameter pressure screw and two, hefty jaws rated at 10 tons. By my calculations a factor of safety of over two is built into this. This does not mean you should try to apply 20 tons with the Harbor Freight 3/4-inch diameter pressure screw puller I describe above. For one thing, the two 3/8-inch diameter bolts I used with the Harbor Freight puller are not nearly as hefty as the jaws on the Snap-On Tool, so the Harbor Freight puller's pressure screw takes much more of the load. The likelihood of a little tilt stripping its threads is higher. But I think my use of the 3/4-inch diameter pressure screw puller and Snap-On's specifications do tend to confirm that around seven to twelve tons of force will install the bushings easily.
  6. If my 91 Civic were only seven years old (instead of 15 in 2006) and had not been driven in a corrosive environment for most of its life, then I do not think I would have had so much difficulty removing the old bushings. I think changing the bushings at about six years or 90k miles (whichever comes first), is prudent.
  7. If I had to do this over for an older car with a lot of rust, I would strongly consider buying used control arms with not more than a 100k miles on them from a nice low humidity, non-corrosive climate part of the country. I would replace the bushings in these arms at a casual pace. Remember that the old bushings in the bent junkyard control arm (the one I used to first work out a methodology) came out much more easily. I think an air chisel would have had these out pronto. My hammer and old screwdriver worked fine. Buying spare control arms would keep my car available. Then I would just swap the arms.
  8. Buying new arms with bushings already installed is also an option. The rear arms for a 91 Civic are less expensive than the front ones.
  9. Except for the inboard bushings of the rear upper arms, all the rear upper arm and compensator arm bushings popped out in one step using the Harbor Freight puller and scraps described above. Neither drilling of the rubber nor sawing of the outer sleeves was necessary for these. For the two inboard bushings of the rear upper arms, drill holes in the rubber, put a long bolt through one of the two bolt holes in the bracket, and use the long bolt as a handle to twist out the bracket. Then push the outer sleeve out using any of the methods described above. The labor to remove the bushings from these smaller arms was far less than that required for the larger ones.






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