How to Remove Stuck BMW or MINI Spindle Strut Clamp Pinch Bolt … Don’t Break It!
This article applies, in general, to all BMW models that use through-bolt spindle to strut (shock) pinch clamps, such as; E46, E90, E39, E38, E60, E65, etc. and all MINIs.
2003 325xi wagon
I just snapped the strut pinch bolt after soaking with penetrant and careful turning. Looks like this could take a while. Any advice besides drilling it out? AND …. any advice on removing the other side? It seems to be stuck as well.
At this point, your only recourse is to drill out the broken bolt section. I’ll give you some tips on removing the other side, below. To drill out the broken one, start with small bits and work up to the larger sizes. Use a slow drill speed and lots of lubricant (some type of oil) to both cool the bit and lubricate the tip. Do your best to get the initial drilling centered on the bolt shank. Once the bolt is drilled out, you can either use a new longer bolt and lock-nut or install a thread repair insert like those from Heli-Coil, Time-Sert or others. If this is done, you can use a new original bolt.
Alternatively, you can remove the complete spindle and strut assembly and take it to a machine shop. The shop can quickly drill out the bolt shank and repair the threads.
How to prevent breaking a stuck (rusted & corroded) strut pinch bolt:
When you encounter a strut clamp pinch-bolt that will not initially move, to loosen, don’t continue to apply more force. You run the risk of breaking the bolt or stretching it so that it will be more prone to break during our further removal attempts or may break or fail to hold torque upon re-assembly. Proceed as follows.
Note that the procedures outlined here are no guarantee of successful removal, but they give you a fighting chance.
1) Heat the clamp ears where the bolt runs through, using a propane torch (Mapp gas works better as it burns hotter than propane). If you happen to have an Oxy-Acetylene set-up, all the better. Apply a penetrant such as Mechanic-All or PB-Blaster to all exposed sections of the bolt to clamp. Apply heat again. Re-apply the penetrant.
2) Apply a pneumatic impact gun to the bolt for just a few hits (“knockas”, to use the technical term) in both directions; clockwise & counter-clockwise. Don’t over do it …. just a few hits. Unless, of course, the bolt starts to move.
3) Repeat step #1 and #2.
4) Try loosening with a breaker bar …. remember; not too much force or you may stretch or break the bolt.
5) If the above steps do not produce results, you can continue repeating and wait a while for the penetrant to work into the bolt and clamp ears. If no-go … continue to step #6.
6) It’s time to get a bit more serious at this point. Use a pneumatic air hammer (air chisel) with a blunt hammer tip installed and hammer on the bolt head and the spindle’s clamping ears (where the bolt is going through). Give it a good long shot with the air hammer, applying firm pressure to assure that the hammer is hitting good and solid.
7) Continue with all of the above steps until the bolt will begin to move. If it gets too tight, after moving, re-apply the steps until it moves again.
Once the bolts is (hopefully) out, clean up the holes and threads in the clamping ears and seriously consider a new replacement bolt. When reassembling, don’t forget to apply the Liqui-Moly copper anti-seize compound to the complete bolt threads and the shank. This will prevent a future repeat of this scenario.
Liqui Moly Copper Anti-Seize:
Mechanic-All penetrant & lubricant:
Replacement pinch bolt: