Got a slight bike rack problem. Well, slight may be an
understatement.
I have a Thule T2 rack which mounts to the hitch on my SUV. Great rack, has served me well for the past 6 years.
Unfortunately, it has spent some time in the weather, and as a result the
mounting bolt and the mounting point on the rack developed some rust and
began to become harder to mount and unmount. During the spring I would work on the bolt and the mount to keep the rust at bay. Seemed to work
well. However from mid to late June I left the rack on during some weather and
found that the mounting bolt was seized. Last evening I attacked the bolt with
WD-40 and tools.
I began to loosen the bolt and slowly (¼ turn at a time)
the bolt began to back out. Suddenly, there was a SNAP, and the head of the
bolt broke off. I stood in disbelief for a few minutes. A problem just got
worse. Closer inspection showed that the bolt had sheared off and was flush with
the bolt hole. The rack isn’t going anywhere as there is still enough of the
bolt outside the hole to prevent the rack from sliding out of the hitch.
But, now I have two problems. First, the rack is even more stuck
on the hitch. And second, while I’m sure I could have the remains of the bolt
drilled out, I’m not sure the rack as a whole would survive, or at least the
portion that mounts to the hitch.
So, if anyone has any suggestions on how to remove the
remains of the bolt I would love to hear them. A do it yourself method would be
of great interest to me as well. 
I have seen something that drills in to the bolt and has a bolt head it's self so you can back it out. Or you could drill it down enough (or maybe screw it in farther) to get the rack off. Then you would have access to the inside of the tube.
ReplyDeleteDid you fix this? Sounds like Eric has the right idea... you can buy a tap that allows you to create reversed threads and insert a special reversed thread bolt into the "meat" of the broken bolt. As you tighten and eventually bottom out the reversed thread both, it will allow you to turn the broken bolt. I'll have to keep this rusty bolt problem in mind because I just bought a new hitch mounted platform rack recently with the same setup, and don't want to end up with the same problem as you had.
ReplyDeleteI just had this occur to me with a Swagman rack that has an identical design. You cannot back out the bolt as it's threaded completely through a solid block of steel inside the rack tubing - over an inch of 1/2" bolt thread. An EZ-Out would most likely break off for the same reasons the bolt head failed (and then you're in deep trouble). Drilled out the bolt. Took a while on my back drilling sideways through the receiver -- very carefully to keep the drill on the centerline of the bolt. Used a blunt conical grinding bit in my drill to flatten down where the head snapped off, followed by a sharp center punch made for steel to make a dimple for the first drill bit to keep it from wandering. Started with 3/16" bit for a pilot hole. Went to a 1/4" bit, then to a 3/8" Titanium Carbide coated bit. All drill bits were made for drilling through steel, not just wood and aluminum. Be patient, keep things aligned vertically and horizontally, let the drill bit do the real work, and it will drill out. Back the drill bit out occasionally to clear the shavings. Hole in receiver and rack tubing is 1/2" but you shouldn't need more than a good Titanium Carbide or Cobalt 3/8" bit and just a little gentle gyration to get the remaining edges of the bolt to fail and pop out on the head end. On the other end, the shank will be about 3/8" in diameter necked down from the threads and it should readily break off as the 3/8" bit gets close to the other side. Do it right keeping the drill on the bolt centerline and you won't damage the receiver or the rack tubing, but will have to deal with the bike rack to extract the (formerly) threaded steel block inside the rack tubing. In mine, the solid steel block is removable and I could get a replacement for it. Had to drill, tap and pull it out of the rack tubing with a long bolt.
ReplyDeleteUsed 50/50 ATF and acetone mixture for home made penetrating oil to attack the rust -- better than PB B'laster or Kroil. Use *metal* oil can for it (the acetone) and keep it away from open flame or heat sources (the acetone in particular). Had I been a little more patient trying the work the bolt out with penetrating oil and rocking it back and forth on the threads after getting it started moving, I might have avoided several hours of patient drilling.
One remark about drilling steel . . . running the drill on max RPM doesn't work well. Only generates heat from friction taking the temper out of the drill bit. Keep the drill RPM down and let it cut the steel, especially with the larger bits.
DeleteJust saw the WD-40 can. It's a great very light lubricating oil. WD = Water Displacement and it's designed to *prevent* rust. However, it's among the least effective penetrating oils for attacking rusted bolts and nuts. PB B'laster is much better, and Kroil is even better. The home brew 50/50 ATF and acetone is even better yet. Keep in metal oil can with squeeze trigger (the acetone will evaporate). Must shake it before each use as the ATF separates from the acetone. ATF is a super penetrant and acetone attacks the rust chemically.
ReplyDelete