front end vibration

[marine165]

Hey, folks.

I've struggled with this problem for as long as I've had the car, but I figured I'd throw it out to you guys to see what you think.
The Cougar has a bad front end vibration at moderate to high speeds (you can start feeling it at 50 or so, and it gets worse from there).
Does anyone else have this problem with their LTD II based car? Even better, has anyone had this problem and managed to fix it? I've replaced the wheels and tires, the idler arm, the radius arm bushings, and the sway bar bushings thus far. Still no good. I want to put a bushing kit in it, but I want to be certain before I spend over $200 that it'll fix the problem. Does anyone think that it might be a problem with the ford steering box? I've been kicking around the idea of getting a saginaw 800-style box out of a Ranchero and putting Gen. 2 Camaro steering box guts in it... do you think this might fix or help the problem? Has anyone put a steering damper on their car with any success? Any thoughts/comments/suggestions would be appreciated.

Mike

[marine165]

Well, an update. One of my outer tie rod ends were worn out (wonder why, huh...) and so I had to replace it for inspection. So I replaced it, got the car alligned and all lubed up... and the vibration got WORSE, by an order of magnitude. What could this possilby be? Does anybody else have this problem at high speeds with their car? Nobody would happen to know any Ford chassis engineers that worked in the late 70's, do you? 'Cause if you do, I'd sure like to bounce some questions off 'em...

Mike

[Gearworks]

im assuming you have eliminated all the obvious things like rocks in the tread, out of balance tire, slipped belt, etc. is it a vertical vibration or a horizontal one? what i mean is, does the vibration show up throughout the chassis? or does the steering wheel wobble?

[Gearworks]

by the way, (iguess it would help if i read the whole thing! hehehe) i have a scan of the necessary parts to update the ford box with the GM guts. i did it on my ttop 79 and LOVE IT! 1 3/4 lock to lock!
email me ill send it too you
[email protected]

[Gearworks]

you know? come to think of it. (after i left the site, of course!) there is a pressed in weight thats SUPPOSE to be inside one of the cooling fins in the brake rotor for balance! check that! Could aslo be a "Shady" or loose wheel bearing!

[marine165]

Hey, Gearworks, thanks for the replies! This board is slow, and the only way to liven it up is if somebody puts enough out there so that somebody will reply. That said...
Rocks in the tread and whatnot is not the problem. This problem has been there through three seperate sets of wheels and tires now.
The vibration is pervasive, but its fairly obviously in the front end. The steering wheel shudders, but only as much as the rest of the car does.
The brake rotors have the weights where they're supposed to be. I replaced both front rotors, so they're not warped or anything.
I've checked the wheel bearings several times for grease, spalling/wear, and tightness, and everything looks fine. I repacked them just recently.
As for the steering box conversion, I'd like to do that, but I have the ford box. I'd have to convert over to the saginaw box before I could use any of the GM guts. Do you know if there is any differences in steering shaft length or anything between the two? I know that the steering box and pump are different... Now that I think about it, I don't even know if the center link is the same or not. There used to be a Ranchero GT in the local junkyard that had the saginaw box and all the steering stuff on it, but by the time I got in there to get it all, they had hauled it off... :(
I'm beginning to think the only way I'll be able to fix this problem is to fabricate a tension rod out of brackets and all thread that I could use to put compression or tension on the tie rods by tightening down on a nut... I've been trying to think how to make one without messing up the steering and getting funky bump steer or something... I'm on my last ideas, really. I wish I could figure out what the bloody hell is wrong!
Anyway, thanks for all the suggestions. Keep firing away!

Mike

[Gearworks]

ok try this (i live for driveability probs on these birds) at speed we MAY be looking at wrong area but i'll give you my latest ideas..

1) strut rod bushings? if they are even remotely worn or loose that would do it.

2) spin a weight off the driveshaft?

3) ball joints in good shape?

[marine165]

Allright, between you and I, Gearworks, we'll get this figured out. ;)

-Strut rod bushings recently replaced.
-Drive shaft is balanced (put the car up on jack stands and ran it up to 85 mph... no shake)
-Ball joints are good; just confirmed by allignment guy when I replaced my PS outer tie rod end.

Keep on trying! Eventually you'll think of something I haven't either confirmed or fixed...

Mike

[Gearworks]

alright, try this... is the "rag unit" good?
that is the slang term for the rubber isolator between the steering column and the steering box. i had one "go south" on me and it was like trying to stand flat footed on the peak of a house! and it vibrated...

[Gearworks]

it may also be the control arm bushings. although you would think that would have showed up on the alignment rack, but not always.
Idler arm?
Pitman Arm?
Center link...

[marine165]

Yeah, the rag joint is good. It went bad on me just after I got the car, so its been recently replaced.
Idler arm has been replaced.
pitman arm looks fine... it doesn't seem like one of those things that would 'go bad'. its just an iron thing on some splines on the output shaft of the steering box... ditto the center link.
And the control arm bushings are something I want to replace, but I haven't yet. I'm waiting to put the polyurethane front end rebuild kit in for that. So yeah, that's basically what I'm down to, as well. I've basically replaced every damn thing... :rolleyes:

[Gearworks]

if and when you do go urethane, go here! these guys are awesome AND CHEAP!! www.suspensions.com
other wise im at a loss so far.

[2-77s, 1-85, 2-86 TCs]

Just taking a wild guess, but are you sure one of the A-frames aren't bent? What about the frame? Couldn't the frame cause that, too?

Rick

[Sean Boyle]

I'd double check the rotors if I were you. I've had new rotors before that were out of round. I've also had rotors freshly turned that were out or round once they were on the car. I think this is part of the reason why it is better to turn rotors while they are on the car. Put I dial indicator on there and confirm that they are true while they are on the car.

Good Luck With It. I know how frustrating a front end vibration can be.

Sean Boyle

[Gearworks]

mike,

did you ever get it figured out?