slider2828
02-27-2008, 10:55 PM
Hey everyone:
Here is I think what plagues most people on wheel shimmy. Here is the list you should do in order. Move on if check ok!
Wheel Bearing Check - 6 oclock 12 oclock shake. If ANY play its time to replace them. (Hub centric rings for spacers, eh... most people don't use them and are fine with it. So I don't hub centric stuff.)
Tension Rods Check - retorque bolts, replace bushings
Suspension check for blown
Tire Balance - go to a friends shop if possible and look at the rim while balancing for rim bent. Also look to see if the tire itself jumps up and down a little which is a check for flat spot check.
Ball Joints Check - check for lube leak, check with crow bar with excessive movent, also 6 oclock 12 oclock movement shake
Tie Rods and Tie Rod Ends - Check 3 oclock 9 oclock shake. Pull down on rod with elbow strength, should be 0 movement. Push toward front and rear of the car, should be 0 movement.
Rack Play - 3 oclock 6 oclock shake, should be minimal about 2mm movement at most
Check suspension all suspension bolts.
Check engine and tranny mounts.
Check DriveShaft bolts and differential output shaft bolts
Steering Rack Bushings - Replace if worn.
Subframe bushings - Use collars because I know most 240's are cracked if not worn by now.
Full Alignment - Weird tow can cause some vibrations. (But it is up to debate that is why at the end.
Here are some symptons: after mentioned checks above
Shaking at high speeds -
if steering wheel also shakes while braking - replace rotors. Also check for frozen caliper. Rotate wheel with brakes off, should be minimal friction front end, and relatively low friction when spining rear.
Preload spring - Nissan Tech Bulletin - I changed this too, but it didn't help too much
Shaking over bump - Here is the kicker, ok probably experiencing bumpsteer and need to get new tie rod ends with bumpsteer adjustment. BUT EVEN if you replaced your rack bushigs with NISMO ones, my problem was here. I FINALLY FIGURED IT out. My Rack was shaking.
What you say even with the Nismo bushings? YUP! I had my mechanic friend rack the car and I turned the wheel with 0 load on the front with the car on. The WHOLE rack was shifting with 0 load. I was like WTF? New bushings that have probably less than 6 months on them. So far I used a heater hose to shim just the top, it helped SO much , but I think you need to shim those rack bushings all the way around.
Just shim the center of the bushing not the sides which have the lip. I think over time with heat, the rack clamps have stretched or expanded and just not enough clamp load to hold the bushings. A large heater hose might be too thick, so find a nice 5mm tacky rubber strip from somewhere (rubber hose from Home Depot?) and shim the INSIDE of the bushing on both sides of the rack and crank the rack back down.
This helped a lot and I hope this helps other people as well.....
Note: I torqued all the rear end suspension links or arms such as the toe bar, traction rod, etc... Didn't move much nor change anything, so I don't think this helps....
Here is I think what plagues most people on wheel shimmy. Here is the list you should do in order. Move on if check ok!
Wheel Bearing Check - 6 oclock 12 oclock shake. If ANY play its time to replace them. (Hub centric rings for spacers, eh... most people don't use them and are fine with it. So I don't hub centric stuff.)
Tension Rods Check - retorque bolts, replace bushings
Suspension check for blown
Tire Balance - go to a friends shop if possible and look at the rim while balancing for rim bent. Also look to see if the tire itself jumps up and down a little which is a check for flat spot check.
Ball Joints Check - check for lube leak, check with crow bar with excessive movent, also 6 oclock 12 oclock movement shake
Tie Rods and Tie Rod Ends - Check 3 oclock 9 oclock shake. Pull down on rod with elbow strength, should be 0 movement. Push toward front and rear of the car, should be 0 movement.
Rack Play - 3 oclock 6 oclock shake, should be minimal about 2mm movement at most
Check suspension all suspension bolts.
Check engine and tranny mounts.
Check DriveShaft bolts and differential output shaft bolts
Steering Rack Bushings - Replace if worn.
Subframe bushings - Use collars because I know most 240's are cracked if not worn by now.
Full Alignment - Weird tow can cause some vibrations. (But it is up to debate that is why at the end.
Here are some symptons: after mentioned checks above
Shaking at high speeds -
if steering wheel also shakes while braking - replace rotors. Also check for frozen caliper. Rotate wheel with brakes off, should be minimal friction front end, and relatively low friction when spining rear.
Preload spring - Nissan Tech Bulletin - I changed this too, but it didn't help too much
Shaking over bump - Here is the kicker, ok probably experiencing bumpsteer and need to get new tie rod ends with bumpsteer adjustment. BUT EVEN if you replaced your rack bushigs with NISMO ones, my problem was here. I FINALLY FIGURED IT out. My Rack was shaking.
What you say even with the Nismo bushings? YUP! I had my mechanic friend rack the car and I turned the wheel with 0 load on the front with the car on. The WHOLE rack was shifting with 0 load. I was like WTF? New bushings that have probably less than 6 months on them. So far I used a heater hose to shim just the top, it helped SO much , but I think you need to shim those rack bushings all the way around.
Just shim the center of the bushing not the sides which have the lip. I think over time with heat, the rack clamps have stretched or expanded and just not enough clamp load to hold the bushings. A large heater hose might be too thick, so find a nice 5mm tacky rubber strip from somewhere (rubber hose from Home Depot?) and shim the INSIDE of the bushing on both sides of the rack and crank the rack back down.
This helped a lot and I hope this helps other people as well.....
Note: I torqued all the rear end suspension links or arms such as the toe bar, traction rod, etc... Didn't move much nor change anything, so I don't think this helps....