JessZ Posted June 30, 2005 Share Posted June 30, 2005 Well I'm excited to be back here at HybridZ, it has been quite some time. Anyway, I was almost ready to sell my Z, but have decided to give one more chance. Here's the deal... The problem: ever since I've owned the car it has shaken up to about 55 mph, and gets worse as I go faster. The steering wheel shakes, the dash board and the seats. What I know: I've had it on a lift and when I put the car in gear and spin the rear wheels and the RPM gauge gets to about 2500 or above, the transmission and drive shaft to shakes pretty bad. Also the motor mount is broken. What I've tried: I changed the U-joints, trasmission mount and stub axle (why, it was a lame idea), and also bought new tires. What should I try: balancing the drive shaft? Would a new motor mount help? Something in the tranny shaking? please any ideas would be awsome. I've owened this car for two years. It is a 71 240Z in great condition, except for this one problem. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted June 30, 2005 Share Posted June 30, 2005 Well I would deffinetly start with that motor mount. You should replace it regardless if it will help or not. Guy Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted June 30, 2005 Share Posted June 30, 2005 Definitely new motor mounts. Then I would try tightening the bell housing bolts and torque converter bolts (assuming you are running an automatic). Balancing the driveshaft isn't a bad idea either but I would try the other things first. Quote Link to comment Share on other sites More sharing options...
PeterZ Posted June 30, 2005 Share Posted June 30, 2005 What I have learned from my time as a mechanic: Steering wheel shakes are from the front suspension (wheel balance) and seat/floorboard vibrations are from drivetrain and rear wheels. Steering shakes that are difficult to find can come from things like: perfectly spin-balanced wheels that don't center properly when bolted to the hub. (You can spin the wheel in the air and see the runout.); The Z cars I have seen like the heavy steel wheels. Many aftermarket aluminum seem to shake more (some sort of centripidal/centrifugal effect) especially if there's any looseness in the steering rack, linkages or the wheels don't center to the hub. I recommend checking steering and suspension with the car on the ground or on the alignment rack. (When the suspension is drooping the bushings and joints can hide wear because the joints are in a different position than when on the ground.) A bad motor maount can effect the driveshaft working angles and certainly cause a driveshaft vibration if it is severe enough. I agree with the others-replace it anyway because it is bad...You can trace driveline vibrations on the lift by carefully removing items one at a time until the vibration goes away. Please tightem the drums to the hubs if testing with the rear wheels off the car. I saw a drum come off in the paddock at Sears Point Raceway; almost took somebody's leg off. Good luck. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 1, 2005 Share Posted July 1, 2005 Before you go any further read this!! Please don't post the same post in multiple forums. http://forums.hybridz.org/announcement.php?f=58&announcementid=2 All other posts deleted. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 1, 2005 Share Posted July 1, 2005 Steering shakes that are difficult to find can come from things like: perfectly spin-balanced wheels that don't center properly when bolted to the hub. (You can spin the wheel in the air and see the runout.); The Z cars I have seen like the heavy steel wheels. Many aftermarket aluminum seem to shake more (some sort of centripidal/centrifugal effect) especially if there's any looseness in the steering rack, linkages or the wheels don't center to the hub. I had a problem related to this issue that was very difficult to figure out. I had a set of wheel spacers that were .010 or something like that too small. They looked like they sat flush on the hub, but they weren't quite there. I had the wheels balanced over and over and over again, never quite got it right. Finally the wheel spacer started to crack and I looked really closely and figured it out. Switched to a lug centric spacer from Coleman Racing and never had a problem again with wheel balance. Quote Link to comment Share on other sites More sharing options...
Trecani Posted July 1, 2005 Share Posted July 1, 2005 First, get that motor mount fixed, should stop the tranny and motor from shaking. If the steering wheel is still shaking, my guess would be the wheels. One of my wheels was bent very, very slightly and caused the car to shake at 50+ mph. Quote Link to comment Share on other sites More sharing options...
Phantom Posted July 1, 2005 Share Posted July 1, 2005 The litany of items that can cause the steering wheel to shake is semingly endless. Ball joints, tie rod ends, TC bushings, bent wheel, aftermarket wheels that are lug centric rather than hub centric like the stock wheel and weren't torqued down with the car in the air, loose rack & pinion, alignment, and tire balance are just a start. Quote Link to comment Share on other sites More sharing options...
Kimi Posted July 1, 2005 Share Posted July 1, 2005 I had similar problems with my hybridZ. The car shaked really bad after 100km/h. The problem was solved when I had the driveshaft balanced. Quote Link to comment Share on other sites More sharing options...
buZy Posted July 1, 2005 Share Posted July 1, 2005 Hey JessZ, Have you checked your driveline running angles??? If your driveshaft and everything else checks out OK chances are this might be causing your vibs. Do a search here and you'll find a wealth of information on this subject. Good luck! Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 2, 2005 Share Posted July 2, 2005 Have you checked your driveline running angles???If your driveshaft and everything else checks out OK chances are this might be causing your vibs. Do a search here and you'll find a wealth of information on this subject. Good luck! Unless he put a staright axle in it and is running 30* that ain't it. The steering wheel shake could be bad balance. I've had bent driveshafts in trucks and a bad balance on my Z. It will shake the shiit out of you and everything else. The easiest way to know would be put the rear in the air and remove the wheel/tires. Put a couple of lug nuts back on so you don't loose your drums and kill someone and run it up to 60 mph. If it vibrates it's your D shaft. Quote Link to comment Share on other sites More sharing options...
dot Posted July 2, 2005 Share Posted July 2, 2005 I tracked my shakes down to a loose lower joint assembly in the steering column. It was noticeable by a mechanical feel in the steering wheel. This was after I tried all the usual suspects, tie rod ends, balancing and a thorough ball joint and rack inspection. Quote Link to comment Share on other sites More sharing options...
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