I'm pickin' up "Bad Vibrations" at speeds over 60 mph

[michaeld]

Yes, to parady the Beach Boys Song, "I'm pickin' up BAD vibrations."

This issue was the icing on the cake of an awful drive last night.  First, "the man" shut down an entire freeway for no apparent reason - without the benefit of any detours - which resulted in my getting hoplelessly lost.  Then I noticed that my engine appeared to be on the brink of overheating (it was getting up to 212 F) in the bumper to bumper traffic.

Finally, I figured out an alternate route and was driving merrily along; when suddenly, I heard a bang or knock that sounded like something hitting the right side or underside of the car.  I pulled over to the side of the road (dangerous on California freeways) and saw nothing.  I pulled away, and within a few miles heard the same bang or knock (it sounded as though I'd driven over a piece of wood that then bounced up and hit the undercarriage).  I pulled over again, and again saw nothing.  But this time, I found that if I accelerated over 60mph, I would start to experience vibration.  The vibration seemed to occur throughout the whole car, but I thought it was concentrated at the front end.  I had 50 miles left to drive, so I drove going 60.  Every time it occurred to me to speed up, the vibration came back and made me think again.

My accelaration, turning (right and left) is fine; but over 60mph the car vibrates.

What do you think?  Could it be as simple as a couple of balancing weights coming of a wheel?  I'm not going to be able to put it up and look at her until the weekend; but I'd sure like to have some idea of what's going on in the meantime!

[michaeld]

Thanks for the response, Styria.

I have an update, which changes my initial situation in my post.

I took the car out today, and this time experienced "issues" at low speeds.  [The other night I was on the highway, and found speeds above 60 mph caused vibration; now I'm seeing that I have problems at lower speeds as well] .

At low speeds, I notice what almost feels like a "bulge" in the tire(s) that results in an uneven roll.  First I thought I noticed it coming more from the driver front wheel, and then later it seemed like it was coming more from the driver rear wheel.  Now I realize that I don't know what part of the car it's coming from; I just know I don't like it!

Interestingly, at 50-60 mph I notice fewer problems than I do at either lower or higher speeds .

I believe it's a wheel/tire issue.  I may have thrown off a balancing weight or two, or I may need to repack my wheel bearings, or something like that ... or perhaps my brakes are causing some kind of drag that is affecting the "true roll" of some wheels?  Heck, maybe a couple of tires have loose lugnuts; I DID have Pep Boys work on the car, and I have recently come to the conclusion that Manny, Moe, and Jack aint too bright (and neither was I for taking my car to them!).

I'd like to have some clearer sense of what's going on before I take the car in for service.  There's that whole, "If you don't have a clue, at least be able to fake that you do" mojo that I like to have going on when I deal with mechanics.  Predatory animals often smell fear and weakness and attack; mechanics frequently smell ignorance and gullibility and take advantage.

[Tomi]

Michael,
If I were you, I would get immediatly under the car and look at those flexible couplings of the main shaft. lift the car so you can turn the wheels and the shaft. use a wrench to see that the bolts are tight in the coupling (they can come loose). check for cracks in the rubber.
If the coupling fails at speed it will get costly and can be dangerous.

It can be your shaft supporting bearing as well, which is hard to see, but can be seen from the trans. side with a flashlight at least partially.

While you are there check also the tires also from the  inside side walls.
regards, Tomi

[Papalangi]

I'd also take a close look at the tread on the tires.  It sounds like you may have broken a belt and that can cause the tread to shift.  It will make the car shift or "roll" side to side at low speed and can explode at high speed.

Michael

[michaeld]

Thanks, guys!

I've got somewhere to start, and that's, well, a start!  In the morning I shall lift the car and start my search for this "bad vibe gremlin!"

[michaeld]

Well, guys, I found my problem!

It's pretty good news, I suppose; my right rear tire tire tread was massively shredded.

I got out of the car twice the other night, but the combination of nighttime and being on the freeway with semi-trucks whizzing by made for poor inspection conditions.  I only hope I didn't do any further damage to the car, as I drove over 50 miles on (what was left of) the tire (albeit at slower speed); I could kick myself for not pulling off the highway and giving the car a more thorough inspection.  What can I say? It was late, I was tired, and I was very frustrated by an inexcusable road closure that created confusion and delay.

Styria and Tomi have a LOT more mechanical expertise than I, I'm sure.  But I was the idiot behind the wheel, and I felt the issue coming from the tires/wheels, rather than from the powertrain.  The weird thing was, I couldn't localize it as coming from one particular wheel.

BTW, does anyone know what brand/model the actual original tires (and spare) were?  The tire that shredded was a Dunlop Formula 70 radial.  It was sitting in the spare compartment and had never been on the road.  I wanted to rotate all the tires on the car into service, and stuck it into the rotation at the first opportunity.  I'm wondering if the tire was in there for years and years, and had simply deteriorated.

Hopefully, a simple tire change will solve my problems.

[oscar]

You know, I've had a rear tyre in a work car make a wobble and thump noise at certain speeds.  Even though we checked it, it wasn't until the tyre was removed that we found the inside had scrubbed thru to the wire.  I was cringing at the thought that something more major was affecting your car.  Let's hope that that's all.

.....  I wanted to rotate all the tires on the car into service, and stuck it into the rotation at the first opportunity.  I'm wondering if the tire was in there for years and years, and had simply deteriorated.

A few years ago I had a rear right tyre literally disintergrate on an F250 whilst doing 130km/h (80mph).  Previously I had seen the fine moulded writing on the tyre was perished with little cracks in it.  I hate thinking about what could've happened.  I have to try and remember that old phrase more often about your car trying to tell you something.  Problems only get worse and cars don't heal themselves.  (except for herbie, christine and brum that we all know are living creatures).

BTW, does anyone know what brand/model the actual original tires (and spare) were?  The tire that shredded was a Dunlop Formula 70 radial. 

Funny you should mention that.  I always thought Merc's were fitted with Michelins or Continentals.  But check this photo of a 1973 350se brochure.  Got a shock the first time I saw it.  Don't tell me your tyre Michaeld had the same advanced, superior tread??  So yes it is possible that Dunlops may have been on your car when new, but I have no idea how old Dunlop Formula 70's would be.

[Papalangi]

I've had several Michelins break apart.  One blew all of it's tread off at 60 MPH on a twisty canyon road.

Early radials were susceptible to taking a set.  If you rotated one to the other side of the car where it would turn in reverse of its original use, it would come apart.  Michelins, at least in my family, are notorious for this.  If your tire was original and had been used before, that's what might have happened.  Of course, it could have been just plain old and tired.

Michael

[michaeld]

Oscar,
Thanks for the info on the Dunlop. 

And to bring in Papalangi also,

The tire had never been on the road.  The wheel looks brand new as well.  I seriously believe the tire was the original spare!  It lasted for under 600 miles, though.  Maybe 29 years is a little too long to wait to use your spare!

Yes, the original radial tires were "directional," and HAD to be installed so that they turned appropriately in the forward ("drive") direction.  Newer tires do not have this limitation.

Here's a pic of what's left of my tire:

The tire lost nearly 2 feet of the inner tread, in a strip over 4" wide!  I'm fortunate I didn't have MUCH bigger problems.
Mike

[OzBenzHead]

... the original radial tires were "directional," and HAD to be installed so that they turned appropriately in the forward ("drive") direction.  Newer tires do not have this limitation.

Interestingly, unidirectional tyres are returning to vogue. Michelin and Pirelli are amongst those brands leading the trend. Particularly beware of this with their ranges of "green" tyres. It makes 5-tyre rotating impossible, meaning one needs only four to rotate (even that's incorrect terminology, as these tyres can only be swapped front-to-rear on the same side of the car) and one as a "permanent" spare - which will, of course, have died from old age and vulcanisation by the time a new set of four is bought, so it's still necessary to buy tyres in lots of five. Is this a conspiracy of forced consumption, or what?   .

As to Michelins cracking up: I believe it depends on where they were made. It is close to (but not entirely) impossible to find "genuine" Michelins (i.e. made in France or the UK) in Oz any more; most Oz-sold Michelins are from China, Thailand, etc. and are not worth the yak poop they're made from. Something I've noticed, too, with oriental Micehlins, is that the country of manufacture is marked on the inside of the tyre, rather than on the usual outside position. Is this an admission from Michelin that they are not proud of their oriental-made tyres?

[Papalangi]

The Michelins that blew on me were either Spanish or French.  They were new in 1972 or so. They were X's, Mom's 1969 Peugeot 504 had XZX's IRRC and they went more than 80K.  Dad's Renault 17 Gordini used XAS's and never had a problem.  Don't suppose it could have been me?

The Tire Rack has info on finding the date of manufacture on tires.
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=11

Michael

[michaeld]

Papalangi makes a point that needs to be emphasized: the age of tires matters greatly!

His link of calculating tire age is a necessity for anyone buying new tires.  Why?  It turns out that it is very common for tires to have been sitting around for five years from the date of manufacture before they finally end up on your car.  As I found out with my situation, time kills.  Try to get 'new' new tires!  Thanks Papalangi!

Ozbenzhead points out the need to do (i.e the correct 5 or 4 tire rotation) tire rotation.  It dramatically prolongs the lifespan of the tires.  It's a good practice; too bad it didn't work better in my case!!!

I'm not quite like some of y'all in choosing tires; I don't necessarily buy the best brand, or even the best tire in a given brand.  Rather, I am price conscious, and seek to buy the best tire in what I consider to be a reasonable price range.  I have found through experience that cheap tires on a larger, heavier car (such as ours) is a bad idea; the tires get shredded.  Rather, I generally seek to buy a solid mid-range tire.  John Hubertz included a link to internet tires that I will consider (I don't have the link, but search under 'tires' and 'John Hubertz.'  The only down side to buying tires from the internet is that you would have no way to avoid buying five year old tires. 
Mike

[Denis]

Hey papalangi

A Michelin X on a W116 sounds like a terrible idea ! this is the original (1948) radial whose design was not intended for a heavy car. Th X was designed for the but Citroen 2CV 

In fact that brilliant little car's suspension directly influenced the carcass and sidewall design of the "X". Lean like mad it did, stick to the road while doing so it also did

Now I know that the W116 did not have "those" tyres but I am pointing out the nature of those early radials.

Denis

Paris, France

[OzBenzHead]

O T but ...

Just in passing, I note that Monsieur Michelin fell through a hole in the universe recently; a relatively young man, too. Likely to be replaced with a non-Family-Michelin bloke at the company helm. Hmmm ...

[Papalangi]

Good morning Denis,
My 450SEL has Firestone Indy 500's.  One of the noisiest set of tires I've owned.  The X's were on my R12 Estate.  My brother lost an X on his R15.  I had X's on my '63 Caravelle S.  Seeing a trend here?  I've even owned a 4CV.  Learned to drive in Mom's '69 504.  I have a picture of my Mom, pegnant with me, driving a Daupine in an autocross.

These days the fleet consists of a 2006 Chevy HHR, 1976 450SEL, 1974 Ford F250 and the 1971 250C.

Michael

PS, the 250C has Toyo's from Les Schwab and I like them a lot.