Cause of Steering Vibration/Normal for ford cars of this era?

Topic: Cause of Steering Vibration/Normal for ford cars of this era? (Read 6967 times) previous topic - next topic

Cause of Steering Vibration/Normal for ford cars of this era?

November 20, 2015, 07:46:38 PM

Hey Guys,

Just got my car back from the garage today with new Mastercraft G/T tires put on and my mechanic, Mike Jr., is concerned about the cars steering vibration at cruising speed of 45 mph or so. It was his first time driving the Cougar following the tire swap. (the tires are perfectly balanced and feel better than the previous tires, they're not the problem here)

However, his dad, Mike Senior, who also worked on my car over summer (did a complete brake overhaul after I bought it), said it was "normal" for "80's Mercuries and Fords" to have a bit of wobble/hop.

So that's two different isolated opinions from two very good mechanics. Mike Jr. suspects the driveshaft to be causing the vibration. Bend driveshaft? bad u-joint?

What do you guys recommend I do? It isn't too severe; it smooths out below and above 45 mph, feels strong on 1st and 2nd gear pulls. But if a new U-Joint or something affordable/simple can cure the problem, it's worth getting fixed now I would assume.

Suggestions? Mike Jr. wants me to drive the car and call the garage back. I may have them take 30 min on Monday to inspect the driveshaft.

Thanks,
Chris :bowdown:

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #1 – November 20, 2015, 08:24:15 PM

Is the steering wheel shaking from side to side or up and down? If it's side to side it's a front wheel/wheel balance issue on the front tires. If it's up and down you should also feel it in the seat/floor/see it in the rear view mirror. If that's the case it can be a rear wheel/wheel balance issue, a driveshaft issue, or a differential issue.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #2 – November 20, 2015, 08:40:54 PM

Ill check tomorrow but i think its usually side to side. If i grab the steering wheel closer to 12 o clock the shaking lessens

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #3 – November 20, 2015, 08:46:11 PM

It could be up and down too though, lol. I need to check tomorrow...

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #4 – November 20, 2015, 09:04:09 PM

Also worth mentioning (I read on Coolcats i think) that the slight "bump'lurch feel" when letting off the throttle is also caused by driveshaft u-joint problems.

I get that "lurch" when letting off the throttle in 4th gear around 45mph.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #5 – November 21, 2015, 01:50:06 AM

Punt your car in drive then pop it in reverse with your foot on the brakes. If it makes a loud thud, you need u joints.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #6 – November 21, 2015, 04:17:55 PM

A thud everytime...

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #7 – November 21, 2015, 05:49:23 PM

U joints are quick and easy. My first time it took about 5 mins. Before you actually do it, crawl under the car while it's in park and jack up the rear wheels, use jackstands of course. Then you can physically grab the driveshaft near the ujoints and feel them for play. A little is okay, alot is bad. Once fixed there will be no play. It's not fun loosing a ujoint. I lost the front yoke out of the trans when I downsiftes on the freeway to pass a semi

I recommend you remove the driveshaft, marking the pinion to driveshaft as it shoopuld be balanced. You will need snap ring pliers, a large c clamp or rent the tool and a 12 point 1/2" or 13mm for the rear driveshaft and some thread lock for those bolts. The tbird ujoint did not fit mine, I ended up ordering one for a 87 gt and it fit fine. Good ujoints are greaseable and will last longer.

I used duralast (autozone) gold and forgot to grease them. I only replaced one and didn't have a problem. It's not much harder then changing spark plugs. With tools and parts on hand, you could probably do it start to finish in 30 mins, maybe an hour your first time.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #8 – November 21, 2015, 05:52:35 PM

I forgot to mention the trans yoke seals in fluid. When you remove it it might just drip, it might gush out. Have a rag and drain pan ready just in case. Once rear wheels are off the ground, put it in neutral to turn the driveshaft.

Always use jack stands and make sure tires are chocked properly before crawling under a car, and do a bounce test.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #9 – November 21, 2015, 06:08:06 PM

Thanks Haystack for all the infomation; however, I'm not a wrencher at all! My mechanic is literally down the street and they are extremely precise and do a superb job; they are well known here in CT and are sometimes booked three weeks ahead. They enjoy working on muscle cars and have done a great job on this cougar since I had gotten it in June. I don't think they will bill me badly for changing out some u joints ( I hope not, I'm 24 and in college and my step dad is about to have a stroke because of the work this car has needed). It has mostly been with parts susceptible to mileadge i.e. brakes, tires, lubricating etc

Now that you have mentioned yoke seals and fluid, I have been noticing small drips beneath the car that don't appear directly beneath the motor, I wonder if that's also from the driveshaft.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #10 – November 24, 2015, 09:03:06 AM

Another possible cause:

http://www.foxtbirdcougarforums.com/showthread.php?39205-Vibration-shakes-steering-wheel-up-and-down-Speed-related-Pinion-bearing

Darren

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #11 – November 24, 2015, 01:18:16 PM

Quote from: Aerocoupe;452513

Another possible cause:

http://www.foxtbirdcougarforums.com/showthread.php?39205-Vibration-shakes-steering-wheel-up-and-down-Speed-related-Pinion-bearing

Darren

Yeah but in my case it was hella violent :hick:. I think most of the issue was from trying to shove the power of a healthy 306 through what was basically a stock 7.5" rear with 3.73 gears and a Traction-Lok.

I'm betting the OP has a u-joint/driveshaft balance issue or a wheel balance issue.

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #12 – November 26, 2015, 07:56:26 PM

Perfectly balanced or perfectly road force balanced??

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #13 – November 26, 2015, 08:39:23 PM

The car's wheels with the new tires seems to performing great; the ride is better than it was before (having the old tires and balancing readjusted twice before). The wheel does indeed shake in a twisting manner as it always had i.e. clockwise and counterclockwise when cruising, especially on shiznitty roads around 1800rpms. I don't get any unusual sounds other than motor and tires, and lurches when changing gears (lurching being the torsional force on ujoints under throttle?)

Even with the wobble, it is not severe at all, passenger doesn't really notice; I just want to get all the problem squared away... I'm bringing her in on the 8th to get the driveshaft inspected so we can see once and for all.

Other than the cars' minor imperfections, I do love the stupid thing. I'm happy I have it. I also got the Reagan-nomics Silencer out of the fender with the help of my twin, definite difference in sound and maybe a little more torque or "placebo".

Cause of Steering Vibration/Normal for ford cars of this era?

Reply #14 – November 26, 2015, 11:32:24 PM

The reason why I asked that earlier is that maybe one of your front tires might be a little out-of-round. That would only show up with a road-force balance, not with a regular spin balance. I'm going thru sort of the same issue with my black bird but I also have to change out the worn shocks and struts and get it re-aligned. Good luck and hope you get it figured out. Oh and my blue bird, when I first got it and put new goodyear eagle aquatreads on it, was smooth riding up to it's red-line.......

Sorry this is a really old picture