New Cougar Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter · #1 ·
Many of you seeing the title of this post might think, "not another post on the same topic!" Indeed, I have read many of the posts on this forum about the infamous high-speed vibration that occurs ~65 mph and that usually is caused by bad tires or a bent wheel. My case might be similar, but I could use some help thinking through my options and next steps.

I'll try to keep the history as short as I can while giving the relevant details, although I probably won't succeed:
  • 99 Cougar V6 MTX - I am the only owner - 119k miles
  • Car is super-fun to drive at speeds 0 to 45mph
  • Above 50mph, closer to 65mph, I get a vibration that I can feel in the steering wheel and through the seats, never through the pedals. The vibration makes this the least fun car to drive, if not scary sometimes. Most of the time it's just an annoying little vibration - and sometimes my passengers don't even notice - but occasionally it's more severe and makes the car feel hard to control. Either way, the vibration is always there - and has been for over 20 years. Not sure why I've lived with it, but I like the car otherwise and I always thought I could figure out how to fix it (but have so far failed).
  • I had an accident in this car about 6 months after I bought it. Hit a rock going backwards that did damage to the right rear and scuffed up the body. I didn't realize the repair shop would only fix the cosmetics, so in some cases it took years to find the extent of the damage and get it replaced, which included:
    • Bent wheel sent for repair to straighten (this one was obvious and done right away)
    • Bent right rear control arm replaced (about 3 years later)
    • Bent right rear wheel hub replaced (18 years later)
  • One of the reasons that some issues took so long to correct was that I took the car to multiple (too many to count) shops (over time), always complaining about the vibration and asking them to figure out the root cause. None of them ever got past saying that I needed new tires - even in cases where I told them to look past the tires. It wasn't until I became more proficient with car work and took the time to examine these parts more closely with the right tools.
  • At one point in my frustration with all the "replace the tires" recommendations (which never actually worked), I decided to get both new wheels and tires, thinking it was a good opportunity for an upgrade. So I made the jump to 17" after-market wheels with low-profile tires. Didn't solve the problem (although this was prior to the wheel hub replacement).
  • Over time I have replaced most of the other things that I thought could have some influence on the vibration:
    • brake rotors all around
    • both front lower control arms
    • front struts and stabilizer links
    • front right outer tie rod (left was good)
    • I didn't really mind replacing all these things because I've enjoyed learning how to do the work myself and I figured I'd keep this car for a long, long time. However, no repair has ever made the vibration go away.
  • At my last tire rotation, I found 2 of the wheels are bent. I took them to my tire shop and their experts said that they can't be trued because the warping is in the face (~20 thousandths). They said they can only fix out-of-round wheels and warping on the back side. They didn't think the wheels were that bad and that they would cause the vibration, but it was visible by naked eye to see the tread weaving back and forth on the balancing machine.
So this brings me to what to do next. The thought of buying yet another set of wheels when I'm not certain that will solve the vibration issue (having been down that road) makes me sick (as well as convincing my wife to spend that money on a 20+ year old car). I do still have the original 16" wheels, but I have no good tires for those. (And last time I drove on that combination, quite recently - those wheels with the old tires - the vibration was there.)

So do I....?
  • Bite the bullet and get new wheels anyway, realizing this might not solve the vibration problem
  • Try to find used 17" wheels to go with my relatively new tires (<10k miles on them) - I know some 01s and 02s came with 17" wheels, but those might be hard to find
  • Try to borrow a set of good wheels/tires to determine if that makes the vibration go away (although I'm not sure how to locate a set to borrow) - That would at least give me incentive for spending the money on new wheels
  • Go back to my original 16" wheels (maybe try to get a replacement for the one that was repaired, if I can figure out which one it was) and buy new tires (thus giving up on my newish 17" tires)
  • Keep looking elsewhere for the true source of the vibration - Anyone know how to check the front driveshafts? Anyone have other ideas for where it could be coming from? I know, it's hard to go here without first eliminating the wheels/tires as a source, similar to my prior mechanics' advice.
  • Move on from this car and find something that isn't a constant source of irritation
  • Something else (you decide)
Then other related questions:
  • Have others experienced this same headache from these Cougars? Are they troublesome cars, or have I just had bad luck?
  • Are after-market wheels really this fragile? Or perhaps it's the combination of +1 wheel sizing and low-profile tires that's the culprit for my current state. And really, these can't be fixed?
If you made it all the way though my really l-o-n-g post, I no doubt owe you a beer if we have the fortune to meet in person. I do appreciate any helpful advice you can offer.
 

·
Administrator
1999 3.0 SilFro
Joined
·
24,844 Posts
Sometimes you'll find that there is some rust or debris between the wheel hub and the rotor, preventing it from seating flush. It's a common place for rust to build up, and it isn't terribly simple to get it all perfectly clean. It's a free step towards troubleshooting that you have not mentioned yet.

Pull the wheels and rotors, and use a wire wheel to completely clean off the face of the hub, in between the wheel studs, and all around the center bore. Then look on the inside of the rotor hat and make sure there's no rust or scale in there either and zip it clean, too. With both mating surfaces extra clean and spotless, you'll be able to see if that makes a difference, or at least eliminate that as a potential cause.
 

·
Registered
Joined
·
24 Posts
Discussion Starter · #3 ·
Thank you for the quick reply. That is something that I checked when I replaced all the rotors. This is a very clean car, generally. Always garaged and only seen snow <5 times (each time inadvertently) despite living in Indiana. I've even had people ask me if it's new. However, good advice and not difficult to double check.
 

·
Moderator
Joined
·
8,590 Posts
The driveshaft idea is interesting - we had that happen on our Accord. A weird front end vibration that turned out to be the driveshafts; I was skeptical, but the shop replaced them, and the vibration was gone. The Accord started doing it about 7 years in, give or take, and it was one of those things that was so gradual it took me a while to even realize it. Perhaps one of yours was defective from the factory, or something damaged it early on.

I still struggle with the idea of a driveshaft being the problem - it's just a hunk of metal - but I think it's more likely the issue was with one or more of the CV joints and they just said "driveshaft" to simplify matters (since that's how they'd replace them anyway).

My car, at 130,000 miles, rides smoothly at any speed, if that makes you feel better about the platform in general!
 

·
Registered
Joined
·
24 Posts
Discussion Starter · #5 ·
Yes, thank you. It's nice to hold out hope that I will eventually figure this out. And fortunately, if it comes down to the driveshafts, I don't believe they are actually that expensive to replace.
 

·
Administrator
1999 3.0 SilFro
Joined
·
24,844 Posts
I had a heck of a vibration on my track car from the drive shaft, but it was only apparent under power at higher speeds. But who knows - you're right, they aren't too costly.
 

·
Registered
Joined
·
1,151 Posts
I had a CV shaft/axle failing that did something similar.
 

·
Premium Member
Joined
·
4,217 Posts
A bad strut gave me a vibration like that.

The good news is, our suspension and steering really is pretty simple and the list of wear and tear items is pretty short.

For the front:
Strut mounts
strut bearings
struts
ball joints
control arm bushings (normally replace the ball joints and control arms together)
Tie rods
wheel bearings
swaybar bushings
swaybar endlinks

For the rear:
strut mounts
struts
sway bar bushings (sometimes the mounting brackets tear right off of the subframe)
sway bar endlinks (almost always bad if you haven't upgraded)
trailing arm bushings
control arm bushings (normally replace the arm)
toe arms (frequently bent)
Wheel bearings

And that's about it.

I suppose motor and transmission mounts and roll resistors, as well as the axles are worth looking into as well. Maybe the steering rack too.
Even though you mention having the problem with factory wheels, I have to ask if your aftermarket wheels have the correct hub hole size, or if you have hub-centric spacers in there.

Its a little weird to have so many bent wheels...I wonder if some of those are incorrectly diagnosed.
 
1 - 8 of 8 Posts
Top