I have a vibration at 80mph.75 mph is nothing and 95 is not as bad as 80mph.I've tried a different driveshaft,rims and tires with no difference to vibration.My car has KVR rotors,Strange 12 bolt and LG torque arm( no rubber mounts)
Any idea's? Last fall when I drove it I do not remember this.It is very noticable now.Stearing wheel is bouncing.

 

Do you feel any vibration (not counting the ABS) in the brake pedal? Could be warped rotors, or even warped rear rotors. My rear rotors are slightly warped, but I can't yet feel it in the pedal (passed a cop and used the e-brake to bleed off a few mph one day and noticed the warp). It could be brake related or an internal tranny problem of some type (internal axle trouble as well). YOu've tried almost everything else. Any extra info you have may help.

 

My brakes have no pulsing at all,but I will try the E-brake deal.thanks.
I think I'll also try my stock rotors in the rear since the vibration seams to be coming from there.
I narrowed it by coasting in nutral at 80 so it wasn't engine related and there is no oil leaks from the tranny tailshaft or axle seals to indicate problems.

 

I had a problem similiar to that on a car once, well it was my sisters car and it happened at like 45mph...but anyways...it was the front tires going bald that caused this to happen, so my advice is to check the tires, ie pressure and balancing...if it was the rotors more than likely you would notice it more when you brake if it was the front...and if it was the rear it would be there all the time...hope this helps

 

there's no way I'm aware of to check balance on rotors, so you might continue with your idea to swap the rear rotors back to original if you think vibes are rear related. when did you change over to new rotors? best of luck

 

sorry to waste space here, but I would agree with malibu and check balancing on all four tires before doing any hardware swaps. it's an easier thing to do and most vibration troubles I've had were tire balance related. BEST...

 

YOu said that the steering wheel is "bouncing"....Don't rule out a dead shock absorber. Are any of them leaking fluid? It could be a bad shock or an out of balance front rotor as well. Good luck!

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by gmag:
<strong> sorry to waste space here, but I would agree with malibu and check balancing on all four tires before doing any hardware swaps. it's an easier thing to do and most vibration troubles I've had were tire balance related. BEST... </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I've tried 2 different wheel/tire combo's already and the same problem is there with both.
I have HAL shocks on there now,but it did it before the HALS.

 

Sound like you need a front-end alignment and maybe have the wheels balaced again. In every vehicle I've owned, what you are describing, has turned out to be an alignment issue.

 

Alignment is another good point......

 

Its called RFV, why do you think my cars name is EVA?

 

It's done it with 2 alignments so far.I'm having deeper gears installed today so I'll check the axles.

love2xlr8-Glad to see your still out there <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Don, you got a PM

 

Hey I have also have small harmonic vibration at 80mph to 85 also. It is harmonic because it will build up in amplitude with constant speed. I think it comes from the rearend gears and the chassis because changing the tire/wheel combo doesn't change the vibration at all, and the driveshaft shouldn't have any critical harmonic vibe issues at 80-85mph. I have 3.42 stock gears and a BMR poly donut torque arm. I think the vibe is normal and unsolvable except by going back to the stock torque arm.

 

Ok I had this problem with my car also. I had Stock WS6 Rims, F1's and a Random Tech Torque Arm. This started after 18K miles or so on my car and only between 65 to 75 mph. It was so bad it would knock the wheel weights off the car. So I replaced the following parts and the vibrations is STILL there

Replace Drive Shaft no go
Replaced Tranny Mount with Poly, no go
balanced wheels over 8 times no go
alignment redone, no go
replaced rear wheels with known good working wheel no go
replace rear end form stock to Ford 9 inch with 4.11's no go
Changed front sway bar, no go

I am at the end of my wits, what else could be causing this VIBRATION!! Sorry just a little mad that even after replacing all the above still no go, should I change out shocks and springs? change out tranny alltogether? I am lost I had a 01 SS with ZERO problems, this damn TA is pissing me off.

Please help!

Thanks

 

ttt any ideas?

 

Check your motor mounts. Something big and non-harmonic is vibrating imo. Maybe when something was installed the mounts were snafu'd.

 

I have a cam and headers is about it. I dont know where the motor mounts are and how to fix em

 

Interesting.
I have a 94 bird suffering from the same problem at about 55-65 mph.It's fine til then and smooth after it up to over 100.Have also gone with different wheel/tire combos,alignment,balance,rotate,upgraded to 98 up front suspension for the brakes but though the control arm bushings/struts might help-didn't.
I only have a 3.4/auto,3.42 posi disc rear.
I am gonna check mine out this week,hopefully.There is some play in the steering and it feels like the intermediate shaft.
Other areas to check;tie rods,control arm bushings,rack,front hubs/bearings,ball joints.
I can't see how mine can be anything but the front end(somewhere) since it is the steering wheel that is just going apeshit on me.But it does sound what others are describing here.
If someone finds out,please post because I am dying to know.

 

At this point should I get a new NR Dennys DS, or invest in LCAs and ADJ PHR combo to combat this vibration issue?

Thanks