Shimmy int the stearing wheel
10-06-2016, 06:15 PM
#1
Instructor
Thread Starter
Shimmy int the stearing wheel
Hey guys I have a shimmy in my steering wheel. I've had the car checked out by mechanic ball joints tie rod stuff like that is good. I had the tires road force tested. Steering wheel shimmies at higher speeds. It's not a back-and-forth it's almost like a side to side. The rest of the car seems to be smooth if you put your hand on the shifter the shifter is smooth the passenger seat when nobody's in it doesn't shake or anything. I'm not sure what this could be. Any input would be great. We're talking about a 1985 the 4+3 trans. Input would be great. We're talking about a 1985 to 4+3 trans
Thanks
Thanks
10-06-2016, 06:23 PM
#2
Le Mans Master
I would get them rebalanced. I dont know how many times I have had to have tires balanced & rebalanced. If there are a lot of weights in one area of the wheel the tires need to be rotated on the wheel.
Last edited by kimmer; 10-06-2016 at 06:24 PM.
10-06-2016, 07:38 PM
#3
Safety Car
If you have the tires swapped to the rear and then can feel the vibration through the seat, it is the tires. If the shimmy stays in the steering wheel, it is something else. This is a good rule of thumb for diagnosing balancing/tire issues.
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fflumpy (10-07-2016)
10-07-2016, 02:55 PM
#4
Instructor
Thread Starter
All the tires have been bubble tested 3x and road forced 1x. The shop that did the last bubble and road force balancing is really good and come highly recommend from several sources.
10-07-2016, 03:41 PM
#5
alignment.
cowl shake.
if you have non-staggered wheels, do the switch test above.
cowl shake.
if you have non-staggered wheels, do the switch test above.
10-07-2016, 06:46 PM
#7
If the balance is fine, and the vibration still exists - check the tire/wheel for excessive runout.... Tires get flat spots - and while most of the time flat spots resolve themselves - it could be that the tire is not quite round - jack up each front corner and rotate the tire with some type non moving reference point close but not quite touching the tire (or better yet use a dial indicator) - does the distance vary as you rotate the wheel ???
If it isn't the tires / wheels - double check the tie rod ends yourself... Chances are with the age of the car - that if they haven't been replaced - they are at least questionable. Get under the car with a light and have someone sit in the car and aggressively move the steering wheel left and right - look for any apparent "lost movement" in the tie rod ends and steering linkage. I've seen a car where a shop said everything was fine - but there was a 1/16" slop in one of the outer tie rod ends...
If it isn't the tires / wheels - double check the tie rod ends yourself... Chances are with the age of the car - that if they haven't been replaced - they are at least questionable. Get under the car with a light and have someone sit in the car and aggressively move the steering wheel left and right - look for any apparent "lost movement" in the tie rod ends and steering linkage. I've seen a car where a shop said everything was fine - but there was a 1/16" slop in one of the outer tie rod ends...
10-07-2016, 10:56 PM
#8
Instructor
Thread Starter
If the balance is fine, and the vibration still exists - check the tire/wheel for excessive runout.... Tires get flat spots - and while most of the time flat spots resolve themselves - it could be that the tire is not quite round - jack up each front corner and rotate the tire with some type non moving reference point close but not quite touching the tire (or better yet use a dial indicator) - does the distance vary as you rotate the wheel ???
If it isn't the tires / wheels - double check the tie rod ends yourself... Chances are with the age of the car - that if they haven't been replaced - they are at least questionable. Get under the car with a light and have someone sit in the car and aggressively move the steering wheel left and right - look for any apparent "lost movement" in the tie rod ends and steering linkage. I've seen a car where a shop said everything was fine - but there was a 1/16" slop in one of the outer tie rod ends...
If it isn't the tires / wheels - double check the tie rod ends yourself... Chances are with the age of the car - that if they haven't been replaced - they are at least questionable. Get under the car with a light and have someone sit in the car and aggressively move the steering wheel left and right - look for any apparent "lost movement" in the tie rod ends and steering linkage. I've seen a car where a shop said everything was fine - but there was a 1/16" slop in one of the outer tie rod ends...
10-08-2016, 12:04 AM
#9
Instructor
I ran into this issue with my '09 Pontiac G8 GT, Some how the front tires developed a flat spot and had some significant run out that would shake the steering wheel L/R at 50-80mph...drove me nuts. I had replaced all the bushing with poly and replaced all ball joints in front but still had the vibration (all the stock bushings where shot at 88K) Today I swapped the rear tires to the front and the shimmy went away!
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fflumpy (10-08-2016)
10-08-2016, 01:37 AM
#10
Race Director
Tire pressure can increase/decrease issues with tires. Even with a "good" balance, lower pressure can highlight imperfection.
I also think ball-joints, bearings, and/or tie-rod ends can be "marginal". By that, I mean they can "pass" but have just enough slop to amplify marginal balancing of tires.
From what I've seen, most balancing is done at the equivalent of 50mph...which doesn't necessarily eliminate all vibration. There is also a difference between cheap/better tires. At least there used to be.... Better tires normally require less weight to balance. Tires that require more weight to balance seem more likely to reveal imperfection at lower tire pressure.
I also think ball-joints, bearings, and/or tie-rod ends can be "marginal". By that, I mean they can "pass" but have just enough slop to amplify marginal balancing of tires.
From what I've seen, most balancing is done at the equivalent of 50mph...which doesn't necessarily eliminate all vibration. There is also a difference between cheap/better tires. At least there used to be.... Better tires normally require less weight to balance. Tires that require more weight to balance seem more likely to reveal imperfection at lower tire pressure.
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fflumpy (10-08-2016)
10-08-2016, 08:24 AM
#11
Safety Car
If you want to check runout with a dial indicator, Harbor Freight sells an OK 1" travel dial and magnetic bases. Get a piece of steel plate, scrap, sledge hammer, anything steel you can put the mag base on and it won't move.
Then when you set Zero, pull the stem out (at the back) rotate the tire and let the stem go back, keep doing this all the way around the tire. If you picked a low spot to set 0, you might have to move the indicator in more and start over.
You don't want the tip to fall off the into the tread voids as the next edge will move the indicator.
I used this method (dial indicator on metal) to shim in disk brakes on the '65 I had and check its wheel runout. Works amazingly accurate. Disk brakes shimmed to .001 total runout stop real nice.
Then when you set Zero, pull the stem out (at the back) rotate the tire and let the stem go back, keep doing this all the way around the tire. If you picked a low spot to set 0, you might have to move the indicator in more and start over.
You don't want the tip to fall off the into the tread voids as the next edge will move the indicator.
I used this method (dial indicator on metal) to shim in disk brakes on the '65 I had and check its wheel runout. Works amazingly accurate. Disk brakes shimmed to .001 total runout stop real nice.
10-08-2016, 09:42 AM
#12
Instructor
Thread Starter
If you want to check runout with a dial indicator, Harbor Freight sells an OK 1" travel dial and magnetic bases. Get a piece of steel plate, scrap, sledge hammer, anything steel you can put the mag base on and it won't move.
Then when you set Zero, pull the stem out (at the back) rotate the tire and let the stem go back, keep doing this all the way around the tire. If you picked a low spot to set 0, you might have to move the indicator in more and start over.
You don't want the tip to fall off the into the tread voids as the next edge will move the indicator.
I used this method (dial indicator on metal) to shim in disk brakes on the '65 I had and check its wheel runout. Works amazingly accurate. Disk brakes shimmed to .001 total runout stop real nice.
Then when you set Zero, pull the stem out (at the back) rotate the tire and let the stem go back, keep doing this all the way around the tire. If you picked a low spot to set 0, you might have to move the indicator in more and start over.
You don't want the tip to fall off the into the tread voids as the next edge will move the indicator.
I used this method (dial indicator on metal) to shim in disk brakes on the '65 I had and check its wheel runout. Works amazingly accurate. Disk brakes shimmed to .001 total runout stop real nice.
10-21-2016, 08:03 AM
#13
Instructor
Thread Starter
Update…so with some of the advice here…i checked for slop in the steering and when you move the steering wheel Back and forth, i can hear a clunking coming from the rack. So im thinking maybe the rack and pinion is the culprit? Steering nuckle? Also the shimmy gets way worse when the top is off.
Last edited by fflumpy; 10-21-2016 at 08:14 AM.
10-22-2016, 09:45 AM
#15
There are two "tie rod ends" on either side (four total)... One at the outer end of the steering rack, where the rack connects to the steering knuckle or front upright, and the other one - & the inner tie rod end. Those inner rod ends can be replaced without pulling the rack. They are also a LOT cheaper than a replacement rack. I haven't done that job - but a number of people on the forum have - supposedly it isn't all that difficult. I would certainly try that before pulling the rack. Check the FSM for the procedure.
BTW - on C4's the top is somewhat structural in that it helps prevent torsional flex. Legend has it that the original C4 designers never designed the car to be topless, but at the very end - the top off option was mandated by the product planners @ GM. Supposedly the engineers massively beefed up the two frame rails that run down the right & left sides to add strength (which would be why you have the horrible entry / egress isuses), but even that wasn't enough. If you corner aggressively with a C4, you want to keep the roof on, and the bolts tight..... Some places have an "X" brace that supposedly stiffens things from the bottom - I haven't heard much positive about it...
BTW - on C4's the top is somewhat structural in that it helps prevent torsional flex. Legend has it that the original C4 designers never designed the car to be topless, but at the very end - the top off option was mandated by the product planners @ GM. Supposedly the engineers massively beefed up the two frame rails that run down the right & left sides to add strength (which would be why you have the horrible entry / egress isuses), but even that wasn't enough. If you corner aggressively with a C4, you want to keep the roof on, and the bolts tight..... Some places have an "X" brace that supposedly stiffens things from the bottom - I haven't heard much positive about it...
10-22-2016, 09:50 AM
#17
Instructor
Thread Starter
There are two "tie rod ends" on either side (four total)... One at the outer end of the steering rack, where the rack connects to the steering knuckle or front upright, and the other one - & the inner tie rod end. Those inner rod ends can be replaced without pulling the rack. They are also a LOT cheaper than a replacement rack. I haven't done that job - but a number of people on the forum have - supposedly it isn't all that difficult. I would certainly try that before pulling the rack. Check the FSM for the procedure.
BTW - on C4's the top is somewhat structural in that it helps prevent torsional flex. Legend has it that the original C4 designers never designed the car to be topless, but at the very end - the top off option was mandated by the product planners @ GM. Supposedly the engineers massively beefed up the two frame rails that run down the right & left sides to add strength (which would be why you have the horrible entry / egress isuses), but even that wasn't enough. If you corner aggressively with a C4, you want to keep the roof on, and the bolts tight..... Some places have an "X" brace that supposedly stiffens things from the bottom - I haven't heard much positive about it...
BTW - on C4's the top is somewhat structural in that it helps prevent torsional flex. Legend has it that the original C4 designers never designed the car to be topless, but at the very end - the top off option was mandated by the product planners @ GM. Supposedly the engineers massively beefed up the two frame rails that run down the right & left sides to add strength (which would be why you have the horrible entry / egress isuses), but even that wasn't enough. If you corner aggressively with a C4, you want to keep the roof on, and the bolts tight..... Some places have an "X" brace that supposedly stiffens things from the bottom - I haven't heard much positive about it...
That would make sense…i def can feel the difference in handling when the top is off. Thanks
10-22-2016, 12:55 PM
#18
Melting Slicks
Mine has had a vibe in the steering wheel that gets worse the more you drive it but is fine after parked for awhile(among other things LOL). Anyways I finally did both my front wheel bearings and it seemed to fix it, but I parked the car. So I'll have to wait and see after a couple months next year.
10-22-2016, 01:17 PM
#19
Instructor
Thread Starter
Mine has had a vibe in the steering wheel that gets worse the more you drive it but is fine after parked for awhile(among other things LOL). Anyways I finally did both my front wheel bearings and it seemed to fix it, but I parked the car. So I'll have to wait and see after a couple months next year.
10-22-2016, 08:11 PM
#20
If all the parts check out good, have the alignment checked by a good shop. Get a print out of before & after. What you will be looking for is (cross) caster reading. It should be even side to side, from around 4-6 degrees. If ones at 3.8 & the other is a 5.2, I could see you having an issue.
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fflumpy (10-23-2016)