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Discussion Starter · #1 ·
The last couple days I've been getting some pretty bad vibration at speeds above 65MPH. Symptoms are very strange. Both times, I got on to the highway and accelerated to about 70MPH. I drove a couple miles at that speed with no problems. After about two miles the car starts to shake, then gets worse and worse over the course of about a minute. The vibration can be felt though the steering wheel as well as under my seat, and even seen on the hood. Basically the whole car is vibrating. Tried shifting to neutral, but no difference. When I slow down, the vibration goes away. I got off the freeway and checked everything I could think of out. I took back roads home with no problems since I didn't get past about 50MPH.

I don't think it's a wheel balancing or alignment problem, because I feel like the vibration would be present as soon as I got up to speed, not a few minutes later. My tires are good. I just checked them and each one is at 25 PSI. The car is running at normal temperature, not overheating. I checked the transmission fluid with the car warmed up and idling in park. It was right at the "F" mark like it should be.

It should be noted that I just took off the brake drums to put on new adjusters since the old ones kept going out of adjustment. Maybe I put one of the front wheel bearings back in the wrong way??? But I think if that was the case, the problem would present itself immediately, not after a few minutes of cruising at 70MPH.

Any thoughts on what I should test? U-joint? Any help is greatly appreciated. Thanks in advance.

About the car: Stock 1963 Galaxie 500 4-door sedan, 352, cruise-o-matic auto, power drum brakes, power steering. The car is a well-maintained, smooth riding daily driver and has not shown these symptoms before.
 

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Check your U joint!

I don't know how rare this situation is, but my 63's U joint was going and I didn't know what was happening. Sounds like how your s is acting. It vibrated so much I shook the bolts loose on my rear license plate and I lost it. Come to find out, I could have had a catastrophic driveline break, and probably only narrowly avoided it.
 

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How long have you had those tires? Since it doesn't do it right from the get go but only after something warms up it could be tire issue. What tires do you have that only uses 25psi? Average tires are 32-35psi. I assume you drive it at that psi all the time so that wouldn't be the issue now.
It could be the bearing is too tight and once it heats up it like warps or maybe not tight enough. I am just guessing if it was fine before you messed with the drums then it has to be something to do with them. I'd take them off and check them out, make sure the lug nuts are tight also just for the heck of it.
Are the brakes adjusted too tight?

That's bout all i can think of at the moment. The Ujoints can act up only at certain speeds also. That's easy enough to check, just get under there, grab the driveline and see if you can wiggle it. I like to block the tires and put it in neutral so i can rotate the driveline and shake it at different angles or however that would be said.
 

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You might lost a brake drum balance weight, some drums have real big ones. I'd check the u joint too, and the tires might start to separate.
 

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Discussion Starter · #6 ·
How long have you had those tires? Since it doesn't do it right from the get go but only after something warms up it could be tire issue. What tires do you have that only uses 25psi? Average tires are 32-35psi. I assume you drive it at that psi all the time so that wouldn't be the issue now.
It could be the bearing is too tight and once it heats up it like warps or maybe not tight enough. I am just guessing if it was fine before you messed with the drums then it has to be something to do with them. I'd take them off and check them out, make sure the lug nuts are tight also just for the heck of it.
Are the brakes adjusted too tight?

That's bout all i can think of at the moment. The Ujoints can act up only at certain speeds also. That's easy enough to check, just get under there, grab the driveline and see if you can wiggle it. I like to block the tires and put it in neutral so i can rotate the driveline and shake it at different angles or however that would be said.
Thanks everyone for the valuable info. I won't have a chance to work on the car until tomorrow morning. I looked pretty thoroughly for a weight around the area I was working and I found nothing. In fact, I don't recall seeing any weights on the drums at all when I took them off. Perhaps they were balanced well enough that they didn't need weights???

Regarding the tire pressure: In the manual, it recommends 24 PSI on the front and rear tires. Is this for old style, non-radial tires? Should modern radial tires be kept at higher pressure than listed in the manual. I've been keeping them at 25 PSI, should I put more air in them?

Anyways, the front tires are only about a year old, and have no signs of wear. The rear tires are about 3-4 years and have very little wear on them. I actually checked out the tires pretty thoroughly when I had them off the other day. I don't think they're the issue.

I don't think the brakes are too tight. That was one of my first thoughts when I pulled over initially, but I gave each wheel a few sniffs and didn't smell anything. If the brakes were dragging, I'm pretty sure I would be able to smell them burning after driving it.

Anyways, I'm going to jack the car up and test all the things that everyone has recommended tomorrow. I will test the driveshaft for play, check the wheels for wobble, and the brakes for binding, and give the tires another once over. I'll report back with my findings.
 

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Regarding the tire pressure: In the manual, it recommends 24 PSI on the front and rear tires. Is this for old style, non-radial tires? Should modern radial tires be kept at higher pressure than listed in the manual. I've been keeping them at 25 PSI, should I put more air in them?
Go by what is recommended on the tire itself not the manual. Tires change, the manuals stay the same. Even the old biased ply tires of yesteryear most always used 32psi so not sure what tires the manual is referring to. But the best bet is read the sides of the tires and see what they recommend.

Good luck on finding the issue! The weights almost look like rectangle shaped pieces of iron welded to the drum on the front of it about 1/2 to 1" in from the edge. You might not have them and would probably notice one missing because of discoloration where it used to be. They look like they are welded on and aren't real obvious though.
 

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Discussion Starter · #9 ·
It's been raining for the last few days here so I haven't been able to get under the car and diagnose the problem. I will report back in a few days when the weather clears up.
 

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Discussion Starter · #11 ·
I took the car over to my friends shop yesterday and we checked out a bunch of things. We checked the U-joint, driveshaft, etc. Everything was fine there. No tire weights or drum weights were missing. All tires were on securely and had no wobble in them when jacked up. We took out the front wheel bearings and they were fine. We repacked them with grease and he showed me how to properly set the bearings in place and tighten them to the right torque. And we properly adjusted the brakes for all four wheels.

I took the car out on the road and lo and behold, exactly the same problem. Got up to 70MPH and went for a few minutes before the car started vibrating. I pulled over and checked all four tires. It seems that the brakes were dragging a bit since they were hot and smelled faintly of burning brakes.

I had to back off each wheel several clicks. Now the high speed vibration issues have stopped, but the brake pedal has to be pushed to the floor to get the car to stop. It's on the verge of being unsafe to drive. I have tried several adjustments since and have had the same problems.

There seems to be no medium between a good brake adjustment and dragging. My theory is that something is sticking in the power brake booster that is causing the brakes to be slightly applied. The booster appears to be original (i.e. 50 years old) so it seems likely that it could be sticking. Tomorrow, I'm going to try readjusting the brakes and blocking off the vacuum line to the booster and see if that solves the problem. Any thoughts?
 

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My car smoothened out a lot after I put on new swaybar links, got another 10 mph before shaking.
 

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Geoffunkel,
I've got a thought. I've had the inside of the flexable brake line going from the frame to wheel seperate inside and keep the brakes applied. Change these flexable brake lines if they are old. Check the springs which pull the brake shoe off the drum to make sure they are hooked to the right place on the shoe. These springs should be ample enough to pull the brake shoe back off the drum. Jim
 

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Durn i actually guessed something right for a change! lol Glad you found it and hopefully it is just they were too tight from when they were installed recently. At least now if they do it again you'll know where to look first and replace the hoses as mentioned.
 

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Will these brakes self adjust with old "backing up and slamming on the brakes" technique?

If the vibration stopped after backing off the brake shoes, then maybe the drum is out of round, or when it was reinstalled it was not indexed to the same position as when it came off. The parts may have been used to each other in a certain orientation, but when not put back the exact same, they now don't get along as well as the used to. If the brakes are properly adjusted and the car vibrates, then I'd think the brakes are the problem. Maybe a rebuild, new drums, shoes and hardware, are in order?
 

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If the front brakes they shouldn't have the self adjusters on them. Rear will or normally the fronts don't have self adjusters at least. If it happens again it would be something to look into for sure like mentioned below/above
 

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You should have self adjusters on ALL 4 wheels, that is the way it came from the factory.

In reading your posts I would look into the possibility that your drum(s) are out of round, or too thin in spots so that the friction of full adjusted shoes is warping a drum, causing the shimmy. Take them off and get them machined. A new drum's bore is 11.030 and can be safely machined to 11.090 if you have to go more than that throw it away and get another drum.
 

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I don't remember my front ones having them, but more than likely do only they just aren't the same as the rear so don't think of them as self adjusters. Never had them work right regardless front rear or both.

If he says it's fine now then the problem he will have is if it does it again. Then it has to be the adjusters or something causing the brakes to adjust too tightly, if he doesn't feel like it or can't afford it right now, then i don't see any emergency to do all that. It could of been they were just adjusted up too tightly to start with which caused them to maybe misshape while hot. But that's just my opinion. Because i am thinking if drums over heat and warp that easily then we would, or people in the past would be changing them very frequently after leaving the emergency brake on til they figure out that smell is from their own car. lol Unless of course it continues to shimmy...

And voice of reason? You could of put your 2 cents in anytime too
 
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