Something Strange at 88 MPH....

[Guest]

OK, so actually it's more like 80+ MPH, but it's got me stumped. My daughter's '87 has a shudder and shake that starts around 80+MPH and gets more agressive beyond 90+.

 

I've replaced everything that I could think of that car, differential, torque tube, struts, springs, two different sets of rebuilt axles and the darn shudder and shake won't go away.

 

Only rotating part I have not changed is the driveshaft. I have a hard time believing it's that. But I guess that's where I gotta go next. What ya'll think?

 

and I know what some of ya'll will say, Why does she need to drive faster than 80+MPH? She drives up and down California, 650 miles at a time, a good stretch of the i-5 fwy if you're doing 75MPH, 18 wheelers will pass you by!

[ColdScrip]

Just an opinion but shouldn't you be looking more towards steering components, ball joints, bushings, wheel bearings, and tire balance/damage? Edited November 26, 2011 by ColdScrip

[psu_Crash]

Just an opinion but shouldn't you be looking more towards steering components, ball joints, bushings, wheel bearings, and tire balance/damage?

 

That's what I would guess too. A worn out ball joint, bad wheel bearings, or steering linkage will make it shake too. Have you had it aligned recently and are you sure the tires are in balance?

[Guest]

Just an opinion but shouldn't you be looking more towards steering components, ball joints, bushings, wheel bearings, and tire balance/damage?

 

Yeah, forgot to mention that. Up front, I replaced hub bearings, ball joints, steering linkage, lower control arm bushings, upper strut mounts, dust covers, struts, springs etc. Swapped out 2 different sets of 7's and 8's on two different set of new tires, have had them balanced twice over and still same problem.

 

In the rear, I replaced struts, springs, upper strut mounts, dust covers, bump stops, along with everything I mentioned earlier.

 

This has been going on for over 3-4 years, it never bothered me when I drove it because I never whent over 75MPH. But it bother's her and it's understandable because of the long distance driving.

Edited November 26, 2011 by louswheel01

[UlrichWolf]

Man, that's tires. You have one that is slightly out of round or something. Either that, or a slightly bent rim. And I'm talking SLIGHT.

 

Most tire balancers won't spin a wheel that fast, only about half that. You get going good and fast, and any imperfections in your tires and wheels come out like that.

 

Tim

[Guest]

Man, that's tires. You have one that is slightly out of round or something. Either that, or a slightly bent rim. And I'm talking SLIGHT.

 

Most tire balancers won't spin a wheel that fast, only about half that. You get going good and fast, and any imperfections in your tires and wheels come out like that.

 

Tim

 

Yeah, I know man, that's the most common logical answer and believe me. I've been to at least 4 different tire shops for tire balance including two sets of 4 new tires. I've even changed two different sets of 7's and 8 wheels including one perfect set with 0 curve rash and dents.

 

I've had Michellins, Falkens, BFGoodrich tires and everytime I've balanced them and it's still the exact same shudder.

[BC_99]

Do you feel it in the steering wheel (shaking in your hands) or thru the seat (vibrating your butt)? If its in the steering wheel you can bet its in the front steering/suspension somewhere. Thru the seat/ rest of the car, it will most likely be drivetrain. You can try flipping the driveshaft 180 degrees before you replace it, and see if its any better or worse.

 

BC_99

[UlrichWolf]

If you suspect driveshaft balance, you can do what we did at Ford for that....two large hose clamps with the screws used as balance weights, so you can fine tune the balance of the shaft.

 

Start with the screws at opposing sides, and move them closer to each other till the vibration goes away.

 

Tim

[ucw458]

Driveshaft may be slightly out of balance. Overdrive gears amplify driveshaft harmonic vibrations. In 5th the engine is spinning slower than the driveshaft and the noise becomes more pronounced. I would say swap driveshafts and see what happens.

 

Also tell your daughter to slow down

[boostdquest89]

 

dust covers,

 

Welp, that was my guess.

[Convette]

I'm going to say drive shaft also. I had one out of balance once and it vibrated like crazy. You could feel it especially in the shifter.

[TRACK BEAST]

Check your flux capictor, once you hit 88 mph.. you'll go back to the future. =)

[Metric-man]

Check your flux capictor, once you hit 88 mph.. you'll go back to the future. =)

That's what I thought too BTTF re-runs lol...I, II, and III

 

Check tire, wheel, spindle, hub, and rotor for run out. engine motor mounts loose or cracked? how about diff mounts ?

Have you or anyone changed the springs in all four corners?

 

If your daughter is excessive in highway speeds check the tire pressure even tire shops don't get it right sometimes.

Check them daily. how do the tires wear ?

[Lance_S]

To check the driveshaft, put the car up on jacks, make sure the suspension is loaded (don't just lift it by the rear end, support the rear A-arms), get the tires a inch or two off the ground and have someone bring the car up to speed. You should be able to visibly see if the driveshaft is at least square on the mounting surface. It may be out of balance, which might not show up on this test, but if it's out of round or isn't bolted perfectly square on the yoke, you will see it when it spins. This is how I found out one of my driveshafts was bent. A bent driveshaft will also cause vibration and it's tough to know if they are unless you see them rotating.

[theRobot]

Check your flux capictor, once you hit 88 mph.. you'll go back to the future. =)

 

Of course, just unplug it, Without a destination date set the whole car will shake violently with nowhere to go.

 

OT;

If you have checked the idler arm(I read through the things you've said you checked and that wasn't there).

 

Then my next guess would be a slightly out of round rim, like was brought up before, the tire places will only spin balance up to about 10-15 mph rotational speeds. That will let them discover most issues, and they can set a weight to counter act that.

But if the rim has a bend, then everytime the tire comes round to the bend, it compresses differently there then it does on the rest of the rim, so you wind up with what feels like a bump. Faster you go, the higher chance you have of tuning that "bump" into something that feels like it'll yank the wheel out your hand.

[BOHO]

I have a driveshaft you can have if you like? It could use some new U-joints but it was fine before I swapped the car.

[BrazilBoy]

Brian had an issue like that it turned out that when he replaced his u joints he got a set with zerk fitting and that threw off his driveshaft balance when he replaced them with non zerk fitting ones issues went away... I believe CarQuest sells the proper ones... Edited November 26, 2011 by BrazilBoy

[Starfighterpilot]

Maybe I missed it in the above posts - but check the drive train mounts for "teeny weeny tiny" cracks.

 

I had similiar issues with vibration at those speeds and I finally resolved it by replacing the tranny mount.

Even tho you don't see 'em - unless you look REALLY REALLYCLOSE - there may be cracks (even internally) in the rubber mounts, and they may cause minute drive train mis-alignments which get aggrivated according to engine RPM and what the drive train's RPM's are.

 

Also check the engine & dif mounts.

 

For What It's Worth.

 

KEN

[nomad]

I vote U joints, driveshaft balance, transmission mount.

[Guest]

I think you guys may have something there about the driveshaft. Its about the only rotating part I haven't replaced. This whole thing started when the U-joints wents out about 4 years ago. The went out about 10 miles from home, I drove it slowly home.

 

I replaced them new with the greaseable type u-joints. It never vibrated til u-joints went out, after the new ones were installed it started the vibration.

 

I'm sure motor mounts, trans mounts, diff mounts, torque tube bushings are toast. So those will be next on my list.

[Fanta]

... I'm not even going to touch this

 

but

 

I'd vote to say driveshaft/u-joints if its at that speed. Fun little trick in a pinch is using hose clamps with the screw/nuts as counterweights and move them closer to each other and see if it helps alleviate the vibrations?

[BOHO]

... I'm not even going to touch this

 

but

 

I'd vote to say driveshaft/u-joints if its at that speed. Fun little trick in a pinch is using hose clamps with the screw/nuts as counterweights and move them closer to each other and see if it helps alleviate the vibrations?

 

Lol.....

[UlrichWolf]

... I'm not even going to touch this

 

but

 

I'd vote to say driveshaft/u-joints if its at that speed. Fun little trick in a pinch is using hose clamps with the screw/nuts as counterweights and move them closer to each other and see if it helps alleviate the vibrations?

 

 

Sometimes I get the impression I am talking to myself. No clue how I come to that conclusion either........

 

Tim

Edited November 27, 2011 by UlrichWolf

[averse]

Have you driven it to experience this or are you just going on your daughter's report? I'm thinking woman driver...

[Guest]

Have you driven it to experience this or are you just going on your daughter's report? I'm thinking woman driver...

Yeah, it was my car until 2 years ago I handed her the keys. Its been having this problem for at least 4 years. I basically replaced all front end steering/ suspension hoping that would fix it

She is making her 650 mile drive back to school today, so I'm gonna have to wait til December to track it down. Maybe have a spare drive shaft with new non serviceable u-joints waiting.