Well for the last 2 days i have been stifening my frame up. I test drove it tonight and it does seem better, but still needs something. my thinking is--when I built this car i used a stock 39 frame. I had it sandblasted. then installed a factory m2 crossmember. I cut out the driveshaft center piece and plated it top amd bottom for late model driveshaft clearance. I am not running front and rear bumbers and the frame always did seem like it had some flex to it. It has never been a problem, but the Big-O guy mentioned a guy who had a kit car of some sort with the same problem and any vibration at all would transfer through the frame. so It sounded possible, so I spent the last 2 days putting cross braces, and 1/4x2 angle along the inside of the frame. Its all bolted in so it can always come out. It was on of those jobs were I was thinking, no one in there right mind would go to this much trouble. The car does seem more solid now. I do have some rotor shake on slow braking, so tomorrow I am going to take the rotors to have turned, just to eliminate that.
You want a dynamic balance,should have done this.you would have weights on both sides of the wheel.Mark the tire and rim together,then drive to make sure the tire is not spinning on the rim.I have seen this when the installer used white grease spray to install the tires.they kept coming back shaking.
Well now I am thinking, try different tires. I had the Death wabble on a newer 2003 Van. People would literlly think that my whol.e truck was going to come apart. I couldn't figure it out but I did have my front right tire get worn on the inside after dealing with the vibration for about a year. I had to replace all the tires anyway as they were getting old. After I replaced the tires, its as smooth as glass. When I hit the brakes it would hop before. I was thinking for sure it was the front end needing work. It's amazing what a bad tire/tires can do.
Do you have a Ford pinto Mii front end or afthermarket. I have a 39 Ford standard, Heights ftend with coil overs very stiff only boxed up front,and chassic engeering kit at trans,with there rearend kit,Granda rear,No boxing at at all.It could be your drive shaft is out of ballance.I guess you have granada rotors up front.My car was to low went with new wheels and tires.If you have reg shocks make sure they are tight up top no up and down play.
Borrow a fellow HAMB'rs rims/tires and see what happens. Maybe your tires need truing. I'm currently experimenting with Dyna Beads that go inside the tire. This has been addressed here before and not everyone has had luck with the beads.
I bought a 62 bel air wagon that had a vibration. Replaced the crappy wheels and tires with new wheel vintiques steel wheels and new tires and still had the vibration. Went through the whole car ( eng, trans, rear and brakes) had the tires balanced several times with no improvement. turns out the lug stud holes were stamped off center. The wheels went up and down like a clown car. Ended up trading the car off. Just one more thing to check.
Sounds like belts are separating, at speed the tyre tends to bulge in that spot due to centrifugal force, hence the shudder. The tyres on my old '66 Fairlane did that after a while and I ended up replacing them all after a tyre literally blew apart at speed (60mph). No more problems after that. I ran a box cutter through the old tyre sidewalls once I'd solved the problem, that way no one else had the same problem as me. When stationary you could not detect any fault, only when driving was it evident.
Thanks all. today I took the rotors off to have them trued because I had some brake pedal surging on braking. I dont really think it was my vibration because I could increase pedal pressure while driving and it didnt effect anything. When i removed the drivers rotor I saw some black in my red grease. the inner race I could spin with my fingers? I have a new rotor that should be here tomorrow. I will see if that makes a difference and then go from there. thanks again for all the input. I will update wed. after i drive it again.
I haven't seen here where you have had the front end aligned? I would suggest maybe checking your front end components for a bad tie rod or ball joint too. Good luck.
Just a couple of items nobody mentioned that can cause vibrations: 1. Transmission tailshaft bushings can get worn out and cause the yoke to "orbit" at speed. 2. Any car running a two-piece driveshaft must inspect the center bearing and also be sure the 2 halves are properly phased. 3. Weak/worn motor and transmission mounts can allow engine pulsations to get magnified (wobbling). 4. Most tire balancers use "hub-centric" balancing (the machine holds the wheel by the hub with the cones instead of by the lugs). A lot of older cars have the wheels mounted "lug-centric" to the car. If there's a difference in centricity a hub balanced wheel will be off-balance when mounted on a lug-centric car. 5. Brake drums can be unbalanced. 6. Brake rotors can be warped.
I am ruling out the driveshaft because in years past i have put the rear on jack stands and run it up to 65mph and no vibration. but after the new rotor if I still have trouble I will repeat that test again. I also crawl under the car every spring to check all bolts, but that doesnt mean i didnt miss something. I pick up the rotor this afternoon on the way to work,2nd shift, and will install it in the morning. thursday morning I am heading to the hot rod reunion. I am trying not to buy new tires yet since those dont have probably 5k miles on them. will update tomorrow, thanks for all the great ideas. Greg
Back in the old days they would spin balance on the car.I had that problem ,and when the got the tire spindling i thought the bumper were going to fall of the car. Tuned it in and smooth after that,days gone by. If you can get someone that can think,put the wheel, tire, and rotor on and balance whole thing.You need 2 tapers that slide on shaft,may be worth the try it.If you have weights 180 out from other i,d say tire ng.
The inner race on the drivers rotor was loose. I replaced the rotor and bearings, and had the passenger rotor turned. It wasnt out much at all. It done better on the test drive. Everything little thing I did helped. I am REALLY glad I decided to check the rotors. That loose race could have left me setting on I-65. Going to bowling green in the morning to get a real feel of how it does on the long haul. Thanks for all the input, I will update after the weekend.
I had this problem on my car years ago, finned buick drums on 40 spindles, with five spoke americans. Rebalanced the crap out of front wheels, still shaked. Couldnt find anyone with an on car balancer which would have fixed it, so I took the drums to a local engine builder who was able to balance them. Perfect ever since.
That was a good find and relatively easy fix. To check front wheel bearings, spin a front tire by hand and put a finger on the bumper... any roughness you'll be able to feel. Sometimes a big problem is a few little things that add up, hope it worked out. Bob
UPDATE, I still have a shake in the car. I really tried to narrow down what the car is doing. going down it wasnt as bad, but i was usually running over 70. coming home, between 62-70 i still have a shake in the steering, and in the peddals, and the doors, with my arm havging out. I could slow down to 60 and after a few miles creep up to 62, then 65 and travel several miles with no problem. then would get the slight shake back so I would slow down and could slowly get back up to speed again for several miles. I could not see that any slight hills, or downhills made any difference. the weird part is that after about 1.5 hours on the road it got much better and I ran about 65-70 and it wasnt bad at all. I raised it up today, and everthing in the front is tight. the front wheels look good and tru. I do have a little runout in the rear tires, which are about 6 years old. Dont really know what else to say but, I am still scratching my head. new tires may be the answer? but which ones? I really dont want to buy 4 just to do it.
I still think you should drop the driveshaft and check for a tight u-joint. Just to rule that completely out, it's a pretty fast & simple procedure. What was good 6 years ago, may be different now.
Go find a shop with the old bubble balancer and you will be happy. I started in the early 70's and that was what we had.(state of the art) As we come to newer technology everything changes. I had a spin balancer in my shop and never like the results. Bought a bubble balancer and now have alot of happy customers. Just because its new doesn't mean its better.
Jeff k , let me know if you try it. Thanks all. I am keeping ALL suggestions and will just keep going and I will update if I find a solution. I wont have time to do much with it this week. My son is coming home from college thursday, and we are going to the road rocket rumble sat. I priced tires for the front earlier and american made big o, made by cooper, are 120 each, so about 250 for fronts, which would be ok if that was the problem. when I drop the drive shaft I am going to have the balance checked while its out. If I can find a set of tires to borrow for the front first maybe I wont need to do that. thanks, greg
I have seen the same problem happen if the drive shaft is just a little too short. It then doesn't go into the trans tail shaft far enough and orbits around at certain speeds or bumps. The other thing to try is balancing beads in the tires. The beads would also take care of a drum or rotor out of balance. Good luck and let us know what it was when you finally figure it out.
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