First, I'm a moderate mechanic that has fair skills and experience, but this has me baffled.

My 2001 has a slow pulsing lightly-violent shimmy that occurs only above 60 mph and into the standard 70-75 highway speeds; and is best described as gradually increasing from smooth to an uncomfortable steering wheel shake that grows over a few seconds to a crescendo then diminishes to smooth again over a second or two...and it is consistent and comes in waves.

Here's what I've done in my attempts to correct:
Replaced steering rack bushings (they were worn and had play in them)
Full four wheel alignment
New set of balanced Michelin LTX MS2 tires

Analysis of other related components:
The shocks and struts don't have a great deal of play and seems to fall within the rule of thumb 'bumper push down and release' test. Although I haven't replaced the front wheel bearings, they don't make the familiar 'bearing gone bad' sound and the tires don't seem to have any play when the frame is supported off the ground, but I don't know how else to test them. There is slight movement (1/4" max at edge of tire) when I attempt to turn a hanging wheel (as the steering would do) when the entire front of the truck is suspended, but I'm not sure if a bit of play is normal. Also, the drive-shaft seems as solid and immovable as possible in all directions when I have attempted to move it by hand with the truck in park; when it is in drive, the end attached to the transmission has a 1mm movement with a slight click...not sure if this is within spec or not. The rear u-joint has no play or sound.

Any ideas???

Thanks in advance for any help!

 

How are your upper and lower ball joints and tie rod ends looking?

 

if you grab the tire (while lifted off the ground) at 3 and 9 o clock and shake, you should have zero play. thats a check of the tie rod ends. if you grab at 6 and 12 o clock and shake you should have almost zero play. a tiny bit of shake is fine but if its obviously loose you have bad wheel bearings.

does the shake happen when you brake at all?

 

there is also this:
http://www.ttora.com/forum/showthread.php?t=161689

my truck has this issue but very minor. it hasnt become a problem just yet.

 

Jack it up and put it on stands fire it up and lock her in and check for bent wheels or axle, flat spots on tires from a previous skid, etc..

 

Thanks for the help! When I grab the wheel (lifted off the ground) at 12 and 6 o'clock there is zero play. If I grab the wheel 3 and 9 o'clock there is play and a clank sound. As I move my hands to say 1:30 and 10:30 there is almost no play at all. So are the tie rod ends bad? Inner or outer? How do I tell exactly...

Oh, and there is a quick reduction of shake when the speed gets close to 60 and below when breaking and the breaking itself does not increase the shaking at all.

Thanks and I look forward to your reply!

 

Thanks! I assume that you're talking about putting the truck up on four stands and simulating the same rpms of the wheels that would equal 70-75 mph road speeds? Hummmm....never tried that before. Sounds fun; I have but two jack stands at this time.

 

It does sound like your tierods are worn, you can never tell the difference if it's the inner or outer, or it can be both. The best bet would be to replace both of em as an assembly. Also would help what model it is 2001 what? Tundra, Tacoma, 4runner?

 

ya i say they are bad. in my experience its usually the outer rods that go bad. keep in mind that after replacing tie rods you need to get an alignment done. might as well do all inners and outers.

 

It's a 4Runner. You know the best place to get/order them?

 

I would order from rockauto Moog parts are what most people choose, but sometimes beck/arnley are oem it's a gamble though sometimes its cheap china knockoffs. Moog so what I've heard is made in USA, I haven't had any suspension problem with my 86 and it almost has 400K miles! I'm sure someone will chime into this.

edit: I've also heard that Deeza and raybestos is of quality too Moog aswell, again i have no experience with these parts I just read a lot of good and bad things of all brands i mentioned but mostly good.

 

Thanks! I found the Moog parts on Rockauto and ordered two inner and one of each side outer. Is there a 'puller' tool that is needed to remove the inner tie rod parts??

 

You can rent an inner tie rod removal tool from your local auto parts store. It's a long cylindrical tube that has fitting on the end for different sized inners. Don't forget to line up your outer tie rods as close as possible so when you go get it aligned it would be easier for them.

 

i usually count the threads on the old one and install the new tie rods ends with the same amount of threads. i have done this several times. it is important to do because you have to drive your car to get the alignment done right? the few times i have done this the alignment shop told me the alignment was almost perfect so it have been a good practice for me.

 

grease all the U-joints and see if it has any impact. If it lessens it, you could have a U-joint going south.

 

I had this problem when I ditched the OEM CV's for a set of O'Reilly ones on my 3" lifted ADD Tacoma.

Went back to normal once I found and installed another set of OEM's.

 

Any update?


Andreas