tight nuts and a rubber mallet

[ricksplace]

Ever have a nut that you just can't loosen, even when you use a cheater bar or a hammer to hit the wrench? The wrench bends.

Put a wrench on the nut and hit the wrench with a rubber mallet, and the nut comes off like it wasn't tight at all. I've been doing this for years. I think it was my Dad who showed me.

My son was helping a friend do some car repairs yesterday and this happened. His friend was dumbfounded that the rubber mallet worked. He asked me to explain why the rubber mallet works when a steel hammer would not budge the wrench. I couldn't explain. I told him it was just FM. (f'in magic).

Can anybody explain this FM?

[Your Old Dog]

I'll have to try that one! When absolutly nothing else will help me get my nuts off, I'll try that one but only in desperation

Maybe it works on the same principle that a rubber tire gives you more pull in a pulling situation besides the obvious softening of the jar. Maybe someone will cough up an answer.

[J Tiers]

Dunno, but someone showed me years ago... you hit the wrench close to the nut (steel hammer). That way works better, even thopugh the theoretical leverage is lower.

I NEVER get any particular success with a rubber hammer.

BTW. impact wrench is the only way to go, IMO short of the blue wrench.

[Rustybolt]

Here's another one my late father-in-law showed me.
Instead of a pickle fork or pry clamp to remove idler arms etc. Place a large hammer like a sledge on one side of the tapered hosing and whap the housing witha large ballpeen. The reluctant idler arm will fall right out. Loosen the nut first.

[andy_b]

i've done the rubber mallet trick before as well. i agree that an impact wrench will get a stuck fastener off IF THE FASTENER IS IN GOOD CONDITION. try the ol' impact wrench on a badly rusted nut, and you will end up with a round nut in short order.

the trick we use is to clamp on a good pair of Vise Grips. then spray with some good penetrating oil. then tap the grip with a mallet in the loosening direction (just a tap or two), then tap in the tightening direction. i've had rusted and rounded-off nuts and bolts come loose in a few minutes of tapping that i was ready to grind off.

andy b.

[Wirecutter]

<font face="Verdana, Arial" size="2">Originally posted by Rustybolt:
Here's another one my late father-in-law showed me.
Instead of a pickle fork or pry clamp to remove idler arms etc. Place a large hammer like a sledge on one side of the tapered hosing and whap the housing witha large ballpeen. The reluctant idler arm will fall right out. Loosen the nut first.</font>

I've heard of this trick for car tie rod ends, too. What you're doing is setting up a kind of ringing in the metal, causing it to fall right out. It's also not so much the hardness of the whack as the speed. You want the metal to really sing.

You probably do the same thing with a ballpeen hammer when you hit the wrench close to the nut.

I tried the rubber hammer trick, but it was a "Harbor Freight" grade dead blow, and it ruined the hammer.

I've also used andy_b's trick - I imagine I'm just loosening the rust. Tighten, loosen, etc. I used this to unstick a rusty WWII vintage trench shovel I got from my pop.

-M

[CCWKen]

The BEST WAY is the way that works in that situation. Heat, oil, air wrench, big hammer, leverage, etc. Don't bother putting wheel locks on your car. I can get them off before you can find the key.

[Wirecutter]

I still chuckle every time I scroll past this subject line.

[ricksplace]

Wirecutter -someone else with a sense of humour like mine? Scary.

[spope14]

The answer is in "bounce back". The same reason you use a rubber mallett to seat a part in a vise on parallels. Use a metal hammer, even an aluminum or brass hammer, things clink and clank like crazy. Can't get that energy to focus on the task at hand...

I have used the rubber mallett trick many a time, and actually have found that a NASCAR fender adjuster hammer (DEAD BLOW) works best to focus the force fully, and to have no bounce back.

[john hobdeclipe]

When I was about 14 or so, I was visiting one of my classmates at their farm. His grandfather was working on the tractor, trying to get something loosened from the underside, as I remember. The bolt would not budge, and the cussing was really impressive. He got a bigger wrench, then a long pipe, all to no avail. The cussing was getting very loud, very creative, downright scary. The old guy was throwing a tantrum, throwing wrenches, blaming everyone on, above, and below Earth for all his troubles, threatening to blow things up, etc., etc., and we were edging away when a neighbor drove up and asked what the problem was. After patiently tolerating a few more minutes of blasphemous cussing and kicking and stomping, the neighbor picked up the wrench, applied it to the bolt, and spun it right off. Or should I say “spun it left off,†as it was a reverse thread.

This was over 40 years ago, and I still haven’t figured out what some of those words meant. But I did learn to look at things a bit more closely before getting too crazy with the extra force.

[Paul Alciatore]

I think the explanation is in the shock value. A sharp strike with a hammer will produce a large force. Ever try pressing a nail into wood? Your full weight (even my weight) will not budge it. But a quick, sharp blow with a hammer will easily drive it.

Same thing with the nut. The instantenous force of the blow will tend to break the bond between the threads. But it won't last long enough to damage anything. Several quick shocks are better than applying the same amount of force constantly. Once the grip is broken, it comes off easily.

I suspect a steel hammer or an impact wrench would do as well. But a steel hammer would damage your wrench.

Paul A.

[ahidley]

I just use the "gas wrench" and burn the bastards off!! Works every time

[panchula]

Here's my take on it. With a rubber mallet you have a longer duration impact. More energy is transfered to the nut due to the deformation of the rubber, it's in contact longer. A metal hammer rebounds much quicker, and transfers less energy. Some of the stuff from mucking around with model rockets as a kid seems to have stuck, Impulse power and impluse duration have very different graphs. Remember to impulsively lenghten the duration when your nuts are tight. Or something like that.

-Mike

[ricksplace]

Mike -

The tighter my nuts, the more difficult to lengthen the duration....

(I just couldn't resist)