Not so good vibrations

Topic: Not so good vibrations (Read 2584 times) previous topic - next topic

Not so good vibrations

September 28, 2014, 11:20:48 PM

Hello all,

I recently bought a 1985 Thunderbird Elan. I have noticed that it has a bad vibration at interstate speeds (65 MPH and above) and also when braking from highway speeds. I have balanced the tires, and checked the front wheel bearings. It only has 79,000 miles and hasn't been driven much since 1992, so I can't believe that the steering linkages are worn. I spun the front discs to see if they rubbed un-evenly (warped rotors) and I couldn't detect anything abnormal. I am in college out of state, and would like this to be a reliable way for me to get home for Christmas. Any ideas or suggestions would be greatly appreciated.

Not so good vibrations

Reply #1 – September 29, 2014, 03:07:52 AM

Checking your driveshaft for wear is pretty simple. Put it in reverse, and with your foot on the brake put it in drive. If it makes a cluck, your ujoints might need replaced.
Oem wheel bearings used plastic retention clips, these should be replaced with timkien brand bearings if they are original. On brake rotors, dont buy the cheap ones. Chinese junk metal that will warp your first panic stop.

A wheel/rim can be balanced while still being bent. Swap your front and rear tires. Vibrations are more easily felt on the front of the car then rear. This should help you pinpoint if its a tire or not.

Not so good vibrations

Reply #2 – September 29, 2014, 01:49:56 PM

I second rotating the tires. Also check the tires to see if theyve got any bulges/tumors on them. That would be a sign that the belts shifted within the tire. Which is bad.

Not so good vibrations

Reply #3 – September 29, 2014, 03:22:01 PM

Have the rear end gears been changed? I'm asking because I battled a vibration issue for years that ended up being caused by changing from the stock 7.5 rear w/2.73's to a 8.8 w/3.73's. The gear ratio change lowered the critical speed on the driveshaft causing it to vibrate badly at hwy speeds. Ended up having a aluminum DS made and it solved the problem.

Not so good vibrations

Reply #4 – September 29, 2014, 11:34:32 PM

Thanks guys!!!

All of the tires are ok. They're cheap tires so they have some indentations, but no bulges or tumors. It only has 79,000 miles and has been driven sparingly since 1992, so I can't imagine the rear end gears have been changed. I'm going to have a friend turn the rotors for me this Friday, and while I have the rotors off, I'll replace the wheel bearings. I'll also rotate the tires.

Not so good vibrations

Reply #5 – September 30, 2014, 07:34:35 PM

For me the vibration like that was due to having the drive shaft off and then putting it back on 180 degrees the wrong the way. I just disconnected it again and rotated 180 degrees and no more vibration.

Not so good vibrations

Reply #6 – October 02, 2014, 08:44:14 AM

When you were braking did the steering wheel shimmy in your hand? This is a direct indication of warped rotors up front. Just because things look good to your naked eye does not mean much with regards to tires and rotors. Get the tires to a shop and have them spin them up and check for separated belts and being out of balance. When you have the front of the car up on jack stands put your hands at the 9:00 and 3:00 on one of the tires and see if there is any play in it by trying to move it side to side. This will give you indication if you have any tie-rod issues or possibly a bad rack. Now put your hands at the 12:00 and 6:00 and do the same thing. This will give you an indication of worn ball joints or something loose in the strut assembly. Repeat for the other side.

You may know all of this but just wanted to make sure you did some basic trouble shooting. Good luck.

Darren

Not so good vibrations

Reply #7 – October 02, 2014, 10:36:23 AM

Hey aero coupe,
Put your hands at 12:00 and 6:00, i thought this was to check your wheel bearings. To check ball joints ive always picked the car up so the tire is a few inches off the ground. Put a pry bar on the ground under the tire, then put one hand on top of the tire. use other hand to pry up. Basically youre cycling the suspension with the pry bar. And if your hand on top of the tire feels a klunk, then youve got bad ball joints.

Not so good vibrations

Reply #8 – October 02, 2014, 11:30:00 AM

You can grab the wheel on opposite sides anywhere on the wheel to check bearing play. I see what you are doing and agree it is a better way but I have had pretty good luck doing it they way I mentioned above. Maybe I am muscling it a little more than I think I am but your way is much easier.

Darren

Not so good vibrations

Reply #9 – October 02, 2014, 01:43:37 PM

Thanks guys!!!

Not so good vibrations

Reply #10 – October 21, 2014, 10:00:16 PM

Hey guys,

Update: The vibration is much less noticeable now. I replaced the rear brakes a few weeks ago (turns out the left rear brake wasn't working at all). I can cruise on the interstate at 75-80 with very little vibration. The issue now is sometimes when I'm leaving the interstate and coming down the off ramp, it will vibrate pretty good around 35-45 MPH while braking. There is no pulsation in the brake pedal, just some shimmy in the steering wheel and the whole car kind of shakes. I've checked out the ball joints and wheel bearings up front and everything is tight. The rotors were fine. I'm planning on taking the car home 425 miles for Thanksgiving, and I'd like to know for sure that nothing's going to fall off when going 75 MPH down the interstate. Any ideas?

Not so good vibrations

Reply #11 – October 21, 2014, 11:43:27 PM

Possibly a bent axle? Did you check the inner and outer tie rods? Does it only do it under braking?

Darren

Not so good vibrations

Reply #12 – October 21, 2014, 11:54:38 PM

Yes, it only does it under braking. I mean, there is a little vibration at highway speeds, but not near like it was. And the vibration during braking is an intermittent thing, and I've only noticed it when I'm coming off the interstate.

Not so good vibrations

Reply #13 – October 22, 2014, 05:24:25 PM

The rotors or drums are not running true. You can seperate them by applying the parking brake slightly whike moving. If it vibrates you know it is the rears. If not it is the front rotors. Braking vibrations are normally always front rotors, Good luck!!

Not so good vibrations

Reply #14 – October 25, 2014, 12:42:44 AM

Hello,

I have been giving this vibration issue more thought. I'm thinking that it could also be that the car was sitting for a few years and that the tires are old and separating.
I am getting the wheels balanced and two new tires put on the front.