Heat the bolt or the nut?

mtelliott · 10-09-2004, 08:41 PM

Trying to remove a stuck nut. It's the nut that holds the swing plate tight. I need to loosen it so that I can make a minor (3/8" increase) ride height adjustment. I got the nut for adjusting the height loose but am having a bear of a time getting the other nut loose. I've been spraying it with penetrating oil for two days and been working a 1/2" breaker bar with no luck. I only have a 3/8 air gun and it's doesn't have what it takes. 1/2 inch air gun would probably do it but don't have one in my tool chest. Thought I might try to heat the sucker up and work it but not sure which one to heat, the bolt or the nut?

Thoughts?

Michael

steve911 · steve911's Garage

You want to heat the nut, so it expands and can be loosened. If you heat the bolt, it will expand INTO the nut and become tighter...

Jeff Alton · 10-09-2004, 10:34 PM

Heat the nut and cool the bolt with a damp rag.

Jeff

vanwyk4257 · vanwyk4257's Garage

Michael,

Another thought if you're not already doing it. Slide a piece of pipe over the handle of the breaker bar and use it to remove the nut. The longer handle gives you more leverage. I have a 30-36" piece of pipe in my garage that's proven invaluable for this. Good Luck!

Zeke · 10-10-2004, 07:45 AM

It's hard to heat one and not the other. After all, they are solidly connected at this point. What happens is that the whole assembley exapnds and contracts and the stresses work the bond in the threads.

What I have found that works best is too heat the nut, but not cherry red if you want to reuse it. While it's cooling, hit it with the penetrating spary. Be careful, if it's too hot, some penetrants can combust. The nut/bolt will draw in the penetrant. Do this in cycles until you can break the nut. Always tighen it first. It doens't even have to turn, just "crack." thenit will come off easily.

This works 99% of the time. Impatience always breaks the bolt.

fredmeister · fredmeister's Garage

Worse comes to worse, cut the head of the nut with a dremel tool until it splits, without touching the thread of the bolt. Replace the nut and call it good....unless the nut is a special size and it is hard or $$ to get.

mtelliott · 10-10-2004, 08:27 AM

Thanks for the suggestions. I'm going to try and heat the nut and see if I can get it to break free. If that doesn't work, I'll either go by some pipe or call around and see if I can find someone who can loan me a 1/2" air wratchet.

Formerly Steve Wilkinson · 10-10-2004, 09:14 AM

Be aware that the biggest, baddest air ratchet in the world is only as good as your compressor. If all you've got is the standard little Sears tank-on-wheels compressor, it won't even be as strong as you are with a breaker bar. I actually bought a boss air wrench to remove a nut (from the end of a crankshaft) and it didn't do squat. Took it to a local shop and they hit it with their air wrench (supplied from one of those room-high tanks) and it came off like it hadn't even been tight.

Stephan

mtelliott · 10-10-2004, 09:19 AM

Stephan, Good point. I've got a large (although Sears) tank. It works pretty well except when I'm doing media blasting.

To all, thanks for the suggestions. Second time I used the heat (MAPP gas) and then brute strength it broke free. Now I can finally get the ride height dialed in.

Michael

Grady Clay · 10-10-2004, 10:53 AM

Michael,

Go over to King Soopers and get some dry ice. Get everything very cold (bolt, nut, spring plate.) When everything is cold, hit the nut only with lots of sudden heat.

It is the DIFFERENTIAL expansion that can release the nut. That comes from having the bolt still cold while suddenly heating the nut and getting the wrench on it right away.

I have several full T-cylinders of Nitrogen (2300 PSI) and ½” drive air wrenches.
I have ¾” stuff also.
If you need, you may borrow my oxy-acetylene setup, just not me.
I wanted to be at PCA DE Second Creek yesterday and today but the bod won’t let me. I probably shouldn’t have gone out and run laps on Thursday and Friday but I had fun.

Best,
Grady

Randy Webb · 10-10-2004, 10:59 AM

Right - be careful with the dry ice - it will 'burn' you. rub it on the bolt so it hollows out to maximize contact with the bolt. then heat the nut.

Zeke also gve good advice.

The impact even a wimpy one will still be impact - but you can hit your manual breaker bar with a hammer.

Wear eye protection.

nostatic · nostatic's Garage

if you're going to play with dry ice, be VERY careful, and wear very thick gloves. That stuff will give you very nasty burns.

anthony · 10-10-2004, 11:49 AM

Quote:

If all you've got is the standard little Sears tank-on-wheels compressor, it won't even be as strong as you are with a breaker bar.

I think the impact gun is more important than the compressor in this case. Even a small compressor will provide enough air to run my Ingersol Rand impact gun that will do 600 ft. pounds of torque in reverse.

Zeke · 10-10-2004, 01:05 PM

Quote:

Originally posted by anthony
I think the impact gun is more important than the compressor in this case. Even a small compressor will provide enough air to run my Ingersol Rand impact gun that will do 600 ft. pounds of torque in reverse.

WE just went over this last week. Pressure and volume are two COMPLETELY different things. You can have a 1 gallon tank with 100 lbs. in it. If you just need a short burst, that and a large air hose would do it (flow volume).

If you've got to sit on the air gun for a whole minute, you need more volume (this time, ballst volume) at the same pressure. It doesn't matter what capacity pumps it up, you need enough reserve and enough flow to match the output of the air gun.

Almost any air gun will deplete all but the biggset rotary compressors. But, they won't do jacksh)t if you can't move the air to the gun.

I've said it everyway I can think of. If that isn't convincing enough, I'll just go my way and others can go their's.

Anthony, I'm not disagreeing with you. In fact, in my mind you are correct. I just need to add the part about the hose and fittings. There is so much disinformation here about air tools. If someone here is using one of those hard plastic coiled up air hoses and can't get results from an impact gun, well, no freakin' wonder!

[/RANT ON]

oneblueyedog · oneblueyedog's Garage

The spring plate bolts (eccentric and clamp bolt) are torqued on at a huge amount. I got mine loose by using a floor jack as suggested by a poster. Breaker bar on the nut, jack on the end of breaker bar, pump it up. The weight of the car helps you.

I only did one this way though. I had not loosened one side on the car and tried to get it loose clamping it into a vise and using a breaker bar. No luck. I took it to a shop with a big compressor and that didn't work either. I then used a 24mm box end extension on the end of the breaker bar and it finally came loose.

The jack method to loosen it was simple and quick.

These bolts are expensive so try not to destroy them, although I doubt you will.

Lee78sc