TimC

Got a fairly big vibration whose resonance node seems to be at about 50, varies slightly but 45-55 is problem area. This happens regardless of rpm or gear, though is worse when accelerating harder. I am thinking possibly u-joint/halfshaft wear issue?

Thoughts?
TIA,
T

led

Bent wheel? I just felt the same thing today but at almost twice the speed

dgz924s

Possible areas....wheel nut has backed off and loose.............wheel weight fell off......bad motor/tranny mounts.....loose lugs.....flat spot on tire.. axle bearing is going out and CV as mentioned. Dal

Legoland951

Wheel bearings or irregular treadwear on the tires from worn shocks/struts.

CT944

I would say tire/wheel/suspension related. look for irregular tire wear patterns.

xsboost90

mine always does this when i have a wheel w/ clip on wheel weights, but switch to stick on centered weights and it stops.

Red1

That would get my vote. When my rear wheel bearings went bad, I had a serious vibration that got progressively worse with speed, independent of whether the car was in gear or not.

Luis de Prat

I'll second the vote for rear wheel bearings. Ask me how I know...

Z-man

My money's on loose lug nuts!

ALWAYS make sure your nuts on nice and tight.

Did I just say that???
-Z-man.

mick944

Yeah,I had the same scenario and it went from wheel bearing(s) to transmission bearing to tires.Obviously,(for once) the tire culprit was the least expensive(after extensive R&D we moved the rear tires to the front and noise went with it.I've had 4 944's and they have all made weird noises from time to time and they extremely hard to diagnose.The noises are just part of the 944 experience(its best to learn to live with them or you will either go crazy or broke).

Rock

Dan mine did this on the way to your house. I think its the exact same thing i was telling you about. I couldnt tell what speed it was at, but it was around 2100 RPMS in fifth (it happened regardless of gear, but thats all i could give you in terms of how fast i was going). IT was horrible. I thought i was going to have to pull off and turn around. It felt like the tires were going to fall off.

dgz924s

If the wheel axle nuts have been removed and not replaced with new ones they will loosen and back off. The nuts are a one time use in this case due to the spinning and inertia. If they were left handed threads this would not be an issue as the nut would tighten as it is spinning. Torque is 130 ft lbs on them and they are locking nuts at that. Pop the center cap and torque the nuts to see if under 130. If so there lies the problem
I will be willing to bet this is the case.

Dal

Steve in New Hampshire

My money is on either a rear wheel bearing or tire. Have dealt with both issues...know the sound well!

-Steve

Oddjob

Check the tires first. Sounds like out of balance tires that have started to cup.

TimC

Followup - mechanic guessed CV joint - not much play but enough. 2 new half-shafts, problem solved. Left outer was worst, which made sense as that kinda felt like source area. Used reman shafts, which brings us to a couple of points - one, ARI apparently does not make the correct halfshaft for late NAs - this is longer shaft; they sent shorter, and they (or at least on this day) only show longer shaft for Turbo, which has different number of mounting bolts. Since this was case, mechanic swapped out all the good bits onto old shafts. In process, he noted that there was WAY too little grease in the boots - be sure if you use reman shafts to check this. Sure is nice to have vibration problem solved!

T