The saga of the death wobble
02-04-11, 09:03 PM
#1
The saga of the death wobble
For the past two months, I have been fighting a crazy death wobble I would get in the steering wheel whenever I reached speeds of 60+ mph. I finally found the problem today and just wanted to post this up in order to help save a headache or $$$ for anyone in the future that may have this problem.
It started when I drove up to see a good friend of mine on christmas. As I drove up, my steering wheel started to shake at speeds of 50+mph. The steering wheel would go about 10 degrees left and right as I drove. I was a bit concerned but drove anyway. A week later, I drove to make the same trip and halfway through my drive the steering wobble got to the point where I deemed I needed to turn around or risk getting stranded, wrecking the car, or worse.
Keep in mind two things have happend at this point to my car prior to the death wobble. I changed over to winter tires, and I had a moment when my car spun out in the middle of the road due to my dumbass using falken tires on the weather we were having. When I spun out, I did not hit anything and just spun on flat road.
I got home, raised the front of the car, removed the wheels and started to inspect things. I grabbed the wheels at the 6&12'oclock position and gave it a good shake. I had play in the wheels! Since our cars have a McPherson strut and lower ball joint, I quickly determined it was a wheel bearing problem (the balljoints are not "loaded" when the wheels are in the air!).
I took the dust caps off and re-set the preload on the bearings. I noticed when I preloaded the bearings to 22lbft the bearings felt loose and didn't tighten up like I know they do when preloading in the past. I backed off and set the proper "tightening" spec using a pull scale. The wheels where nice and tight again.
I looked around some more, my front drivers side coilover adjuster (the big "nut") was loose! I immediately tightened the adjuster nut. Basically my coilover was flopping around a bit. Besides this, everything on the car was snug!
I get the car back on the highway, the death wobble got better, but now only showed at speeds of 60+mph and would come and go, it was unpredictable!
I took my car back to the tire store and had them recheck the balance. They come back and tell me my balance was "way off". Great, this was my problem all along. Wrong. That day I drove back up to the main cities and the vibration was worse, I couldn't accelerate as that cause washer machine vibrations now! I took it to the nearest discount tire and had them rebalanced. The balance was off by 2 oz.!!! Damn discount tire people!!! Ok so this time my car will be running great right? Wrong, the washer machine vibration went away, but the death wobble was there at 60+mph. WTF!!!
I drove back home. Remembering the wheel bearings were feeling "loose" when I checked them, I went ahead and bought new wheel bearings. I cave-manned the old races out of the hub and slapped new bearings in. Preloaded the bearings (this time they felt nice and tight), and set the "tightness" of the nut using the pull scale method. Ok, this will fix my problem now!!! I go on the highway, it's still there!!!!
At this point I am baffled. I noticed my steering rack is a tiny bit too loose. I took the rack apart and retighten and the the preload according to the fsm and the flyingmiata method. I reinstall the rack, it's nice and firm again. I go for a drive, the damn vibration is there!!!! I am really baffeled now.
I took my car to sears and had a front end check to get a second opinion. The guy tells me everything is tight and snug, and if this started to happen after I got my tires. I told him yes and he said it probably is defective tires. I go back to discount tire frustrated and they agree to send me new tires. I was really happy, I was hoping this would fix the death wobble.
Got my new 4 tires, this time in the O.E. size. They noticed I had a "slight" bend in one of my wheels, but shouldn't be causing this to happen. I note it and go for a drive, the damn death wobble is there. At this point I was going to drive the car into a lake.
I searched the web and i looked in the FSM, I looked over everything I possibly could. The fsm did say bad "stabilizer bushings" could cause a steering wheel vibration/shake. I didn't have a front or rear sway bar before this and the car was fine, desperate I installed the front sway bar and went out for a drive. The front was much stiffer, on the highway though, the death wobble was still there. I ordered a new wheel thinking this may be the problem.
Come today, I got my new wheel in. I looked in the FSM and the last possible thing I have not looked at was the wheel alignment. Note: it is very rare for the alignment to cause steering wheel vibrations/shaking, it usually is loose steering/suspension components or bad balance that cause this. I decided to have sears check the balance (and swap out the "bad" wheel) on my wheels and re-do a front end check. If all is good do a alignment. The guys did the work and I asked for the alignment spec. sheet that gives the before and after data.
I walked out and went in the car. When I looked at the sheet, my front drivers wheel had crazy toe out while my passenger side had crazy toe in. I couldn't believe it, the front wheels where tracking in crazy directions. I go for a drive on the highway, I felt safe and confident driving the rx7 again. The last thing I could have ever though was wrong on my car, was wrong.
Moral of the story: if you have a death wobble and the front end checks out good (everything snug), have the alignment checked asap (sears does free front end checks!). Don't be stubborn like me : P Also, if you install new wheel bearings, re-check them after 100+miles of driving, they tend to loosen up just a bit and need re-adjusting.
It started when I drove up to see a good friend of mine on christmas. As I drove up, my steering wheel started to shake at speeds of 50+mph. The steering wheel would go about 10 degrees left and right as I drove. I was a bit concerned but drove anyway. A week later, I drove to make the same trip and halfway through my drive the steering wobble got to the point where I deemed I needed to turn around or risk getting stranded, wrecking the car, or worse.
Keep in mind two things have happend at this point to my car prior to the death wobble. I changed over to winter tires, and I had a moment when my car spun out in the middle of the road due to my dumbass using falken tires on the weather we were having. When I spun out, I did not hit anything and just spun on flat road.
I got home, raised the front of the car, removed the wheels and started to inspect things. I grabbed the wheels at the 6&12'oclock position and gave it a good shake. I had play in the wheels! Since our cars have a McPherson strut and lower ball joint, I quickly determined it was a wheel bearing problem (the balljoints are not "loaded" when the wheels are in the air!).
I took the dust caps off and re-set the preload on the bearings. I noticed when I preloaded the bearings to 22lbft the bearings felt loose and didn't tighten up like I know they do when preloading in the past. I backed off and set the proper "tightening" spec using a pull scale. The wheels where nice and tight again.
I looked around some more, my front drivers side coilover adjuster (the big "nut") was loose! I immediately tightened the adjuster nut. Basically my coilover was flopping around a bit. Besides this, everything on the car was snug!
I get the car back on the highway, the death wobble got better, but now only showed at speeds of 60+mph and would come and go, it was unpredictable!
I took my car back to the tire store and had them recheck the balance. They come back and tell me my balance was "way off". Great, this was my problem all along. Wrong. That day I drove back up to the main cities and the vibration was worse, I couldn't accelerate as that cause washer machine vibrations now! I took it to the nearest discount tire and had them rebalanced. The balance was off by 2 oz.!!! Damn discount tire people!!! Ok so this time my car will be running great right? Wrong, the washer machine vibration went away, but the death wobble was there at 60+mph. WTF!!!
I drove back home. Remembering the wheel bearings were feeling "loose" when I checked them, I went ahead and bought new wheel bearings. I cave-manned the old races out of the hub and slapped new bearings in. Preloaded the bearings (this time they felt nice and tight), and set the "tightness" of the nut using the pull scale method. Ok, this will fix my problem now!!! I go on the highway, it's still there!!!!
At this point I am baffled. I noticed my steering rack is a tiny bit too loose. I took the rack apart and retighten and the the preload according to the fsm and the flyingmiata method. I reinstall the rack, it's nice and firm again. I go for a drive, the damn vibration is there!!!! I am really baffeled now.
I took my car to sears and had a front end check to get a second opinion. The guy tells me everything is tight and snug, and if this started to happen after I got my tires. I told him yes and he said it probably is defective tires. I go back to discount tire frustrated and they agree to send me new tires. I was really happy, I was hoping this would fix the death wobble.
Got my new 4 tires, this time in the O.E. size. They noticed I had a "slight" bend in one of my wheels, but shouldn't be causing this to happen. I note it and go for a drive, the damn death wobble is there. At this point I was going to drive the car into a lake.
I searched the web and i looked in the FSM, I looked over everything I possibly could. The fsm did say bad "stabilizer bushings" could cause a steering wheel vibration/shake. I didn't have a front or rear sway bar before this and the car was fine, desperate I installed the front sway bar and went out for a drive. The front was much stiffer, on the highway though, the death wobble was still there. I ordered a new wheel thinking this may be the problem.
Come today, I got my new wheel in. I looked in the FSM and the last possible thing I have not looked at was the wheel alignment. Note: it is very rare for the alignment to cause steering wheel vibrations/shaking, it usually is loose steering/suspension components or bad balance that cause this. I decided to have sears check the balance (and swap out the "bad" wheel) on my wheels and re-do a front end check. If all is good do a alignment. The guys did the work and I asked for the alignment spec. sheet that gives the before and after data.
I walked out and went in the car. When I looked at the sheet, my front drivers wheel had crazy toe out while my passenger side had crazy toe in. I couldn't believe it, the front wheels where tracking in crazy directions. I go for a drive on the highway, I felt safe and confident driving the rx7 again. The last thing I could have ever though was wrong on my car, was wrong.
Moral of the story: if you have a death wobble and the front end checks out good (everything snug), have the alignment checked asap (sears does free front end checks!). Don't be stubborn like me : P Also, if you install new wheel bearings, re-check them after 100+miles of driving, they tend to loosen up just a bit and need re-adjusting.
02-05-11, 10:39 AM
#5
Full Member
Join Date: Dec 2010
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
When analyzing the front, toe-out on one side cancels toe-in on the other. It just means the monkey doing the alignment didn't have the wheels straight. You have to zero one side to get the toe. For example: LH +4, RH -5 is equivalent to -1 toe.
