Thank you for the info on the frame. I am going to use a 46 pickup frame for my 40 Ford pickup and I want it to sit like yours. I know it will need a kick up
I'd go along with finding a shop with an on the car spin balancer and have them spin the front wheels up to speed. If you were closer we would use one of mine. Over the years I have found a lot of drums that were out of balance and a few rotors that were out of balance. I have also found a couple of hubcaps that were way of on balance. That was a big part of what I did when I did front end work at a Pontiac dealer in Texas years ago. You can just jack the truck up with the front tires a couple of inches off the shop floor and set something close to the tread and turn the tire by hand to see if it isn't running true. That will give a quick eyeball of if one isn't running true. Tire stores should have a dial indicator gauge to check run out more accurately. It's a pretty simple job to check the runout in the tire both around it and sideways.
I agree with spin balancing the wheel assemblies on the car FIRST. I had a similar problem with a vibration and threw away money from on the car1 end to the other. Finally figured out the torque convertor and flywheel was where the problem was coming from. I changed both at the same time = problem solved . I would have bet money that it was coming from the front end.
Hello, In our 2nd 40 Ford Sedan Delivery, we also had some high speed shakes in the front end. We tried having the tires/rims balanced off the car, no improvement on the shakes. Next came a set of new front shocks, a full brake drum rebuild, cleaning, truing the drums. Before the next step of using an “on car balancing”, I took the sedan delivery to a tire shop in Inglewood for truing all of the tires. As much as we all think the factory tires are round, the shop’s machine proved us wrong. There was so much rubber on the ground that I thought I just drove to Seattle and back three times for tire wear. But, the tires were now, perfectly round. Now, on to the balancing for the final fix it. So, finally, we tried the balancing of the rims and tires while still on the car. That helped tremendously. No more shakes or wobbles at any speed, even after a few road bumps. The tire shop said the out of round tires, however slight will create problems at different speeds while driving. Jnaki All of the ideas of others are also a fix of sorts. Balancing tires/wheels on the car, truing the tires, new front shocks, cleaning and truing the drums, all led to the fix of the shakes on the 40 Ford Sedan Delivery. If your shop does not have the "on the car" balancing machine, the off car machine is pretty accurate. Just make an appointment on a Wednesday. (days of the week maladies...) So maybe the tire truing will help, then balance on the big machine.
OK I can see this may be a little dangerous if not done safely but how about jacking up the rear axle, put on jack stands and run it up to speed. This way you know if it is the drive shaft, rear wheels, u-joints shaft angle and all of that. And you would know if it is in the front wheels, this cuts the possibilities in half. Just don't crash into anything, and mess up that VERY nice truck.
While you're checking everything else for balance, check the rear drums. Austin-Healeys suffer from "scuttle shake" right at the 55 mph area and smooths out as you drive through it. For years, everyone tried all the front end fixes without curing it. Turns out the rear drums in these cars were very poorly manufactured and most were out of balance. Balancing them cured the problem. Funny thing is when driving the car you would swear the problem was in the front end somewhere and never think a problem in the rear would affect the front that way.
My '37 Chev has a steering wheel shake I have never fixed. Has similar running gear as o/p; MII ft end, 350/350, 10 bolt. I have replace almost everything in the last 25 years with no fix. New wheels/tires, balanced wheels on car, new driveshaft, rebuild front end, new steering rack, steering damper, harmonic balancer, torque converter, and who knows what else over the years. 57-62 miles an hour in neutral or in gear it shakes.
Exactly proartguy, that's where I'm at. The only thing I have not checked is the rotors, new rear end with new drums, new wheels and tires, new rear springs, checked everything I can think of. Gonna check each front wheel for out of round and if so, why. Thanks guys.
The shakes, come on much in the way a childhood 'swing' gets a push, each time an out of balance 'rotating' mass comes around. Let us know if you find the culprit.
More frustration, used a highly scientific method of checking for round, wood block freshly cut with a sharp edge up against the tire,........perfect, tire is round. Move same block to side of wheel with pencil marking the rim all round, you got it, deadly, right on, no wobble or out of round. Tomorrow, got help coming, will jack her up and check rear stuff at speed. Tires were inflated to 32 pounds, dropped to 30, truck weighs 2770 pounds, gonna try that too. Hang tight, more action to come. LeRoy.
Please read my quote above, again. It is possible that you are experiencing a harmonic vibration in your truck that is not due to a specific part or parts that are out of balance. Everything has a natural harmonic frequency at which it will vibrate if stimulated. Many cars have had harmonic balance weights placed strategically to dampen this/these vibrations. For examples, I seem to remember certain models of early Camaros having what looked like large black (weighted) tin cans in the far corners of the trunk......many Fords have weights hung off the back of the transmission and/or differential. No doubt there are more examples, but you get the idea. These solutions were engineered at the ‘Factory’ to eliminate unwanted sympathetic vibrations resulting from a specific combination of parts, no single one of which was ‘out of balance’ in the conventional sense. You might try ‘weighting’ your steering wheel or the upper column, with a firmly attached weight, of a few pounds mass, and go for a drive and see if anything changes. Ray
You might be right Ray, I'm leaning now to the rear of the truck, gonna jack it up tomorrow and see it at speed on jackstands.
Some vibrations can be eliminated by a steering damper. I'd model Ray's concern, to a tuning fork behavior. Possible, but if components are mounted securely, and sized to handle the loads, I've not had a chassis build exhibit a ''pronounced" resonant frequency vibration. It seemed to require one rotator out-of-balance, a wobble, else radial or axial 'eccentric'.
So....underneath today with the truck in drive, driveshaft turning slowly. IT'S BENT, right in the middle, ever so slightly, you can barely see it, but it's there. Never been off the truck till this winter, all i can think is it got bent or was bent when it was made, twenty years ago. It'll be some time till I can fix it, but a new one is next. LeRoy.
Regards bent drive shaft,thing about parts your going to replace anyways,is giving a try at fixing it,is only lost time if it dose not work. So if it were me, I'd carefully mark highist point of bend an besure there is no kink on other side from that at all. Then lock shaft on place with highpoint up with "X"add a wood block on the top,use what ever,jack,press,strap etc. to push down on high spot,slow a little,stop check,repete as needed tell,it checks straight. Try it again too see if that fixed vib. If not,all you lost is time. Get new one ! "If part is no good as is,trying to fix it can't hert the part"
With driveshafts, and other things like that, being straight doesn't guarantee balanced. You need a straight AND balanced driveshaft. A new one made by a pro sounds in order.
To balance a drive shaft, I heard you can fill the bath tub with water and put shaft in, it will float with the heavy side down. Use a hose clamp to balance by rotating it so the screw on the clamp is at the light side of the shaft. Guess you could use two clamps if needed. I never tried this but it sounds like it would work. Now to get the dirt ring out of the tub when you are done.
Perhaps theoretically, but I don't think most driveshafts will float...even after removing useless weight of u-joints and yoke. Maybe a large diameter aluminum shaft...maybe. most certain skinny steel driveshafts will not float. It's all about displacement. Ray
My roadster has Ford hubs and spindles and Buick Drums in the front, and although not a heavy shake, you can feel some vibration at speed. Part of this may be an old set of Coker bias ply WW tires I'm planning on replacing soon. Gonna give Diamondback WW radials a try, I think If I still have a shake, I'm gonna get on the lathe and make myself a mandrel and adaptors to precisely mount up the assy. of hub and drum, check for any eccentricity in the hubs and lug studs as wheels are lug centric rather than hub centric, also consider checking concentricity of the hub register shoulder used for lug centric wheels and maybe trim that if out of true. Will be a bit of trouble to do all this, but having 50+years as a machinist plus a big old Monarch lathe will come in handy Then I plan to talk an automotive machinist friend of mine who has a nice engine balancer in his shop to spin up those hub/drum assemblies and balance them.
I had a bent drive shaft in my '68 Mustang GT. The vibration came in at 2500 RPMs and got worse with speed. That was about 50 MPH. But I knew it was dinged when I installed it. I was able to find another one quickly. Take it to a driveshaft shop and see what they say.
The Jalopy Journal
