a broken belt in a tire??

Hey everyone,

Sorry to wait so long to bring this to a solution, but my simple mind only recently came to a definitive answer as to the shaking and vibrations my car suffered with for way too long.

The main, and unrelenting, problem was that all of the Torque Rod bushings needed to be replaced. Even though my terrible examination and testing of these bushings seemed fine, they certainly were not. Hence, I would get vibrations accelerating, cruising, braking at most speeds between 20mph-75mph + as the driveshaft was able to "flop" around wreaking all sorts of havoc through the entire drivetrain. Getting these bushings sorted out and keeping the bolts torqued (I didn't use any thread lock at first) solved all the shaking and vibrations I was experiencing.

Along the way I replaced so many parts, and each was an improvement. So, even though my mind was strained, the car is now the epitome of luxury and handles incredibly (with the addition of some suspension modifications including bigger sway bars front and back, lower chassis braces, and greater positive caster and negative camber). I certainly don't beat on any car but it is nice to be able to drive mountain roads with more confidence and a bit of fun.

Anyway, thank you everyone for sticking with me and I very much appreciate all of the help and kindness helping this old goat get his wagon back up to snuff. I haven't read back through all the posts but I'm sure I ignored some excellent advice along the way as I tend to do, so sorry for that and again thank you ladies and gents. If anyone needs any clarification or elaboration on anything please let me know.

Maybe I'm just a paranoid, neurotic, ... fella.

While waiting on a center bearing and carrier to be shipped out to me I have been driving my S80 T6 and a Chrysler mini van a few times. Both cars, to me, vibrate and shake. Others who drive them say I'm crazy.

So after several months, a few hundred bucks, and a lot of aggregation I think I'm putting an end to my quest for a silky smooth ride. And to everyone's rancor while I go on and on with this thread.

On the plus side, many much needed parts were replaced and I'm happy about that.

Thus, I will put this thread to rest.

Thanks for all the help and for putting up with me

:)

Update on my ongoing vibrations:

I installed the new guibo/flex disc , and while I fell less vibrations, the issue continues. I also tried shimming the center bearing mount up and down. This changed the speed and intensity at which the vibrations occurred but didn't stop them. Also tried matching the angle of the transmission and the front part of my 2 peice driveshaft.

Something I noticed while shimming the carrier bearing:

Right at the center bearing, the driveshaft is very hot. The first u joint and second piece of the driveshaft is not hot. The first piece of the drive shaft is hot near the center bearing but not hot where it attaches to the guibo.

I also just started to hear a scratchy whine from under the car, I believe it's the center bearing. Also while putting in the guibo the carrier for the center bearing seemed pretty soft and floppy.

I just installed the new FAG center bearing and Febi center bearing carrier less than two years ago.

Y'all think the center bearing and carrier are the problem with my car vibrating?

Thanks again for all the help everyone.

Hey everyone,

Thought I would give an update on this as its been a while.

Since I last posted I installed new inner tie rods on my steering rack, replaced struts, strut mounts, strut bearings, front wheel hubs, and rear shocks on both sides with good used parts.

Still have vibrations, although now it is less of intermittent vibrations but more like intermittent times of smooth driving. Inspecting my driveshaft agian, all checks out good except for a suspect guibo/flex disc. Ordered one today but I'm not too confident this will cure the problem.

Anyway, I'll let y'all know if I ever get to the bottom of this

Hello,

I replaced the steering rack and inner tie rods with a good junkyard unit after finding up and down play in my old rack. I was hopeful this would solve my issue but the wheel shudder and vibrations remain.

Also took my car into an alignment shop today and they couldn't find anything amis.

The vibrations seem to be getting worse and still occur with no pattern that I can gather. After messing with my strut mount I did find that the front stunts are bad. Could this be a possible cause?

Any other suggestions on where to look? Sorry again for dragging this out but I'm at my wits end.

Thank you much

Hi,

Highly confident that my cam rack or p.s. pump or both are to blame for my steering wheel vibrations. Found a pinched return line from the pump to reservoir thanks to the new engine mounts lifting the oil pan off the line. Never gave it much thought before but my car developed a whine, similar sounding to an electric motor months ago. Put a Stethoscope on the ps pump to confirm.

Anyway I replaced the pinched line in hopes that the pump is still good. I didn't bleed the fluid properly and the vibration was got exponentially worse. Now the car is parked uphill with the wheel at full lock to the left. Atf fluid in reservoir is saturated with tiny air bubbles currently.

A few questions:
1) Should I follow these directions?
http://www.swedishbricks.net/700900FAQ/Steering1.html#Cam%20Gear%20Rack%20Power%20Steering%20Fluid%20Bleeding%20Procedure
Or should I leave the car like I have it now, put wheel to full right after a day and wait again. Then follow the above procedure?

2) Or is my pump maybe to far gone and causing the air in the fluid?

The rack is bone dry under the dust boots.

Sorry for the long post and drawn out process I'm going through, but I much appreciate all the help.

Hey all,

I was able to replace the strut mount stud that I snapped and have driven the car a bit. For anyone else as dumb as me, you can pound the stud out fairly easily to replace.

I still have the steering wheel shake at seemingly random times. In the next week or so I will replace the inner tie rods and more thoroughly inspect my brake calipers, in particular the slides. Also, while replacing the strut mount stud I snapped the sway bar end links so those got replaced as well. The bushings at the control arms were shot.

I'll let y'all know what happens in the coming weeks.

*As an aside the new Corteco motor mounts have made the car significantly smoother. The throttle seems more responsive with the tourque going where it needs to instead of rocking the engine to the side. Also, I don't know if genuine mounts are like this but without the engine running the engine kind of jiggles if I try to rock it side to side by hand. Lastly, the low end sounding knock I've had for the last 70K miles or so (almost sounded like rod knock) has completely gone away with the new mounts.

Thanks again for all the help everyone

Hi all,

Update: got the corteco motor mounts in today and took the car for a quick spin.
Steering wheel shake is still there. I didn't take it for a long run but got it up to 60. I will update again when I get it on the highway as to whether the vibration in the seat and floor are still there.

On the plus side the passenger mount was completely done for. Now my engine sits well above the crossmember. Much smoother feel at idle and much smoother ride in general so far. Also, a knock emminating from the lower engine seems to be gone. Very happy about that.

Back to the drawing board I suppose. I have a set of inner tie rods I never installed. After separating the inner and outers there was no in and out play but you could swivel the tie rods in their ball joint with extreme ease. Also, the passenger steering rack boot had separated and there was some debri in the inner tie rod ball joint. What do you all think about that?

Will probably examine the brake calipers again as well but I am confounded.

Any other input is much appreciated.

Hello and thank you for the suggestions,

I'm not sure on the motor mounts. I can pull the engine a bit if I grab the oil fill and yank. But the engine doesn't move much, if any, while idling. Do you know how much clearance I should have between the oil pan and crossmember?

Haven't checked out the rear yet but will tommorow.

The car has disabled abs (unplugged the wheel sensors)

Today I just pulled the brake calipers off. Rotors seem fine (I don't really have a way to check for runout) and the pads are wearing evenly with a lot of life on them. Tires spin pretty freely. Also greased the guide pins but they seem to move relatively freely. It's been a while but on Bendix front calipers can you pull the hollow rod, that the bolt goes through, out of the rubber boot for greasing? I didn't want to pull it out and not be able to get it back into the boot.

Marked the harmonic balancer, however, I just timing with a timing light using the mark on the harmonic balancer and it was at 12 btdc.

I do have a mechanical, clutch type fan that has all its blades.

A/c works just fine, already had to use it this year. Do you recommend that I take the belt off of the compressor to disable?

Today I also checked the driveshaft center bearing and bushing and greased the u joints, all seems well there. Rotated tires front to back again for the fun of it.

Also, and I know this is ill advised, I cut the engine off at speed with no change in vibration.

Probably should also mention that the alignment is a touch off with the car pulling very slightly right. But this has always been the case, at least for the last 70K miles.

Leaving for work so I'll let y'all know if anything changed.

Put a chalk line on your front damper to see if it has come apart.

Check your fan to see if a blade might have come off.

Disconnect power to your AC compressor.

After an episode of bad shake, pull your plugs and look at them.

While I see that killing the engine would eliminate the items above, they are quick and easy to check.

Did you check the condition of your rotors and pads?

Does your car have anti-lock brakes?

A fan clutch?

Weird!
No brilliant answer here. Just a few things to check. Motor mounts, rear end/axle and rear suspension bushings.