Broken Bolt Rear Suspension

[peter carroll]

I have pulled a couple rear swing arms in my day on parts cars, and usually one of the 3 bolts breaks where the shims are located. Of course it happened on my good car today.(even though I pulled the plastic caps on top and soaked them with WD40. I then smacked the heads with a hammer and heated them. Two came out with clean threads, the third broke and the bolt remains were quite rusty. My thought is to drill from the bottom all the way through and then thrubolt it and use a lockwasher and nut. Anybody ever do this or have a better idea? Thanks, Pete

[norustscott]

WD-40 ... although a great product ... is not a penetrant...PB blaster, Kroil .. and others work better...drilling out and thru bolting sounds fair...

[Jim Smolka]

If there is any bolt left, the old blue flame wrench might to the trick with a pair of new pair of vice grips.

If the bolt is broken off inside of the hole, Snap On makes a drill kit that has the drill bits and a collar for the drill bit. The collar goes over the bit and fits in the hole. It serves as a centering device for drilling the hole. It is also possible to make your own custom collar.

[jmargush]

I did this and it is about the only solution, but is a real pain since that is a grade 10 bolt and very hard. Get several drill bits and take your time.

On one of mine the head snapped off so I was able to weld a piece of steel to the bolt shaft and then it came out probably from the heat of welding. The other broke down inside the hole so I had to drill it.

Good luck

[Jim Smolka]

If the bolt is 8.8 steel, most drill bits work fine. If it is 10.9 or 12.9, then extra care is needed. Rapid Tap is a great coolant - cutting fluid. Also, drill bits mfr by Holt seem to work best (IMHO) on 12.9 steel.