Hard to remove bolts

[Scott Tipton]

Looking for tricks or tips on removing stuck or galled bolts.
The chain tensioner bolts on a KTM aluminum swingarm. Have tried using a good penetrant, I can get the bolts to turn a little with great force. Dont wont to push it to far for fear they will snap off! If I can get them out I'll sure use some anti-seize lube on the next ones.

 

[RM_guy]

Those bolts tend to rust on the inside of the swingarm. Moisture gets on the threads and the rust buildup won't come through the threaded hole.

Try turning them in a bit than then dousing them with liquid wrench or something to break down the rust. If the bolt is tight in the hole than the penetratent can’t get in there. Then try to remove the bolt but after you feel some resistance loosen it up again. Doing this over an over again will eventually break up the rust. The idea is that the threads in the swingarm will clean the rust off of the bolt. It can take a while but may save you having to but an extractor when you break off the bolts.

I remove those bolts every time I take off the rear wheel and clean and anti-seize them. Cheap insurance.

 

[Tom Cox]

Oxidation

People will describe what has happened many way but it's simple oxidation of the metals due to moisture and corrosive chemicals in the soap from pressure washers. Both the bolt and aluminum has oxidized, bonding them together like a glue. The portion of the bolt that extends past the threaded aluminum section into the body of the swingarm is rusted (oxidized) also. All of this is fighting against you. How bad do you want to fix it. I've had good luck drilling 2 or 3 small holes in the swingarm (less than 1/8th inch), inline with the bolt (on the backside of the swingarm - wheel side ). Drill down until you hit the bolt. Now pour whatever your favorite penetrating oil is, into the holes and let it set over night. In the morning if the oil has gone away, pour more in and let it set over night. Now try to take the bolt out. If it's still turning so hard that you think it will break off, it's time to use some heat. You will need to get the aluminum up to 375 or 400 Deg. F. Normally this will require the use of an oxygen-acetylene torch. You're trying to heat the aluminum fast enough, so you don't put a lot of heat into the bolt. The aluminum will expand, releasing it's grip on the bolt. Heat the general area of the bolt location from the back side (wheel side), moving the torch around so you don't have any localized heating damage. Use a kitchen thermometer to check the metal temperature. When it's up to temperature start taking the bolt out. The rust on the threads of the bolt that extended into the swingarm body will be your real problem. The rust could still damage the aluminum threads. If the bolt starts to turn hard you can pour some oil into the holes you drilled, and yes it will smoke as it is heated by the hot aluminum. Or you can try heating the aluminum more. Once you get the bolt out, run the correct tap down the hole, to clean up the threads. If you've damaged the threads beyond salvage, it's time to put in a hele-coil. Clean the oil out of the holes you drilled and plug them with a sealing product. A little note here, silicone products draw moisture when they cure. Be sure and use plenty of grease on the bolt and put grease in the hole before putting a new bolt back in. I know it sounds like a lot of work but it's worked for me and I haven't had to hele-coil any yet.

 

[RM_guy]

If you plan on using heat then just use a propane torch. That alone can get hot enough to melt the alum so be careful. An oxy-acet torch can get you into trouble fast if you aren't careful and you will end up needing to buy a new swingarm.

 

[83MX80]

on my dad's 72 honda XL 175 enduro bike it has the same problem but the bolt is has been bent so many times. but its rusted at the same time. so im just going to cut the nut off the thread it through the opposite way (into the bike). i say cut it off and thread whats left of it. but see if i dont fix it then i cant ride it. because we can tighten up the chain but as soon as tension gets on the chain(taking off from dead stop usually) it loosens back up. but i know what the prob is i just gotta take the time and fix it. i havent been at home for the past couple of weeks now. and i go back to school on wednesday so im thinking of playing with it tomorrow.

 

[Tom Cox]

Heat

The question of how to apply sufficient heat.
Before I comment on heat, let me make one other suggestion. Take a punch or brass drift and place it on the head of the bolt, then give it several hard hits with a heavy hammer. This is a little like using an impact wrench. The force applied can loosen the bolt in the threads.
Now lets talk about heat. Have you ever used a propane torch to heat up an engine case to remove a crank main bearing. It takes a long time because the aluminum case is a heat sink. That's why aluminum cooling fins are used on everything from electronics to radiators. It transfers heat rapidly. You end up heating the complete engine side case to get the bearing out. In your situation, using either torch, the rest of the swingarm will act like a heat sink and wick away the heat you're applying. That's why people put an engine side case on a hot plate or in an oven to get it hot. A propane torch just takes to long to put enough heat into the item. Personally I've not seen anyone successfully melt aluminum of the thickness you'll be working with using a propane torch. This example goes back to using a propane torch to heat up an engine case to get the crank main bearing out. The engine case is 3/32 to 1/4 of an inch thick. However if you hold the torch long enough in one spot I can't tell you it won't damage the metal. From experience I know with a propane torch you'll be holding it there a long time. Regardless of which torch you use, move it around to spread the heat and not have any localized over heating. If you're not comfortable with the torch concept, put the swingarm in an oven at 400 degrees. The only problem is you're subjecting the bolt to the direct heat of 400 deg. along with the aluminum. And your mother or wife won't appreciate the burnt grease / oil smell coming from her oven. Everyone has had different experiences and success in performing their own repairs, if you're uncomfortable performing the task take it to your dealer and let him repair it or take it to a machine shop and let them get it out. In either case take some money along. What I've suggested may seem extreme and may not be necessary for your situation. Try other methods first. Whatever method you decide to use (you know this part) put plenty of anti-seize or grease on the new bolt. Good luck.

 

[Oldschooldeathwish]

I Have allwats had great success wiht "shocking" the part. get It as hot as possible without melting it then dunp Ice cold water on it very quickly. It will help. Allways works for me