how do I get a bolt unstuck that just wont move?

Question

The plug for adding rear end fluid to my car won't move. I've already tried penetrating oil and it still wont budge!

Answer 1

Try out heating it a bit.

Answer 2

My favorite trick is to heat the stuck fastener/plug with a propane torch, but you're probably too close to the gas tank and fuel lines for that one. Still, try a heat gun, the kind you might use for stripping paint or softening plastic (but be careful with it anyway!). Direct the heat right on the plug and the area around it. If there is any "rust weld" between the threads, this will break the seal and remove the worst of the resistance.

The next trick is to use vibration. I have a four-pound engineer's hand-drilling hammer (purchased from Sears) which is ideal for the task; it's a short-handled sledge, with about a 12" handle and a four-pound steel head. You want as much mass as you can get in a small area because it doesn't take much motion or speed to get a lot of impact. A series of "light" taps with this hammer will also help crack the corrosion seal between the threads. (If you have an impact gun, it does the same thing but it uses pneumatic power to do so; this is just how you duplicate an impact gun if you don't have a compressor.)

Finally, learn my poem about leverage:

I'm greatly indebted to Archimedes:
Thanks to him, I don't need to eat my Wheaties.

Archimedes, of course, is famous for the quote, "Give me a lever long enough and I will move the Earth." Every toolbox needs about a 2' - 3' (70cm-1m) piece of pipe, of a suitable internal dimension to slip over the end of a breaker bar. A suitable lever multiplies your own force by the length of the lever; a three-foot piece of pipe triples the amount of torque you can apply to the fastener. (As a demonstration: if you weigh 200 pounds and you are hanging from the handle of a 1-foot wrench, you are applying 200 foot-pounds of torque. If you hang from the handle of a 3-foot wrench, you are applying 600 foot-pounds of torque. Make sense?)

Put the appropriate socket on a non-ratcheting tool of some kind (sliding or pivoting is OK, but you WILL break the ratcheting mechanism if you try this on a ratchet), slip that over the plug, and then slide your pipe over the handle of the un-ratchet. (Or if your diffs are like some of my cars, the filler plug has a hole in it that takes a hex key; slip the short end into the hole, slip the pipe over the long end, and lever it THAT way. ...And now that I think of it, I helped a friend once work on a car where the drain plug was removed by the half-inch socket drive key. You surely know more about what your fille plug is like than I do. :-)

Then pull for all you're worth.

You may need to do a combination of all three -- heat, vibration, and the "cheater bar" -- to get a really stuck fastener to come loose.

DO be sure the car is securely on jackstands before you do this -- personally, I HATE working all the way under my cars because I'm terrified of having one fall on me and crush me.

Answer 3

try penetrating oil like you did, make sure you have the proper tool
for removing the plug (you don't want the tool to slip). and use a
johnson (breaker) bar to crack the plug loose. You might not get
the leverage with a ratchet. If this does not work you might have to resort to heating the case . Watch out for fires!

Answer 4

If you are to the point of not having any edges to grab to then it may be time for some power tools. I have encountered this problem and what I suggest is drilling the center out to relieve the outward pressure of the threads against the mating surface. Once a big enough hole is drilled insert a easy-out and remove the thread section of the plug. I always coat my drill bit with grease to catch any filings. This method has never failed me!!!

Answer 5

Please do not heat the bolt if it is for filling the rear differential! There is oil and grease and the like that tends to burn well if heated enough. You don't want to do that. Just keep soaking it in penetrating oil and trying to remove it, it should work eventually.

Answer 6

there is some product called gunk liquid wrench
you spray it on wait a while and wow it will loosen almost anything-it can be purchased at an auto place like where you can buy different auto parts & things,and also like walmart-k-mart and so on i don't want to advertise for anyone but this is an exsample.

Answer 7

This may sound odd, but try to tighten it a little bit and then try to get it loose - I saw a plumber do this successfully with a stuck toilet inlet valve. Good Luck!

Answer 8

WD40 but give it time to work or try a really thick grease?or perhaps phone the AA,RAC?

Answer 9

take a propane torch to the bolt just to get it warm then remove

Answer 10

Liquid Wrench overnight if it is rusted

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