Yes, just as the thread title shows, I've still got that stupid nagging vibration I can't seem to get rid of. I got my motor mounts replaced which helped soften the feel of the vibration, but it's still there. I've got a harmonic balancer picked out and will purchase soon too. Anyway...so I've noticed over the last week at highway speeds that sometimes it will pick up a vibration that is fairly strong. When I let off the gas, it goes away and doesn't pick right back up. It's random and that's what worries me. I can't MAKE it happen, it just does occasionally...usually once or twice per drive to/from work, which is around 35 miles @90% highway miles. It doesn't seem to be anything with like tie-rods (new), alignment (recent), thrown wheel weights or anything like that. Can power steering pumps cause vibration issues? Can a dying harmonic balancer give intermitten vibrations like that? Any other ideas?
Have you replaced the transmission mounts? That will also, cause the vibration. I don't think it would be the harmonic balancer.
Yeah, my transmission mounts were replaced around a year and a half ago. I gave it a look when under my car replacing the motor mounts and it looked good and was still mounted nice and tight.
Do you feel the vibration through the steering wheel or through the seat/floor? If through the steering wheel then most likely it is suspension/steering related. If through the seat then could be engine/drivetrain related.
It seems much more in the seat/floor than anything else. It's odd because it just randomly starts while at a constant speed on flat road going straight.
U-Joints are also only about a year old and when I recently got my driveshaft balanced, the guy doing the work said they looked good.
I replaced those around 2 years ago, and I don't feel any binding/grinding or any loose play in them...but still a possibility.
that sounds like a driveshaft vibration. a common mistake is to put the wrong u-joint in the rear of the shaft. the ford uses what is called a big cap 1310 u joint yoke on the diffs. the cap should fit perfectly into the yoke. if a standard 1310 u joint has been put in it will not be supported properly in the yoke. also the two tabs on the yoke can get worn out and not keep the u joint centered in the yoke. this will cause it to vibrate like you describe because some times it sits centered and other times it will be off center.
Everything fit up snug and I haven't had a problem up until recently with it, so the only way I could see this being the problem is if the two tabs on the yoke got worn out, like you suggested. I'll give it a look and see if there's any play there.
I went through all of this for the past few years, and finally found that it was exhaust drone. So, have you made any changes to your exhaust? Are you running loud mufflers?
No, I haven't made any changes to my exhaust yet. Is there an easy way to troubleshoot this? My car still has the single exhaust/muffler. The guy who had it before me put some louder muffler on it and it sounds alright, but not too impressive. I've got some flowmasters to put on when I can afford it, but not at the moment. I've been waiting to add them because of the drone they produce until I can get this vibration figured out. This recent addition to my vibration problem hasn't been around long and that's why I'm wondering if something big is about to go out on me, namely the balancer. I hope it hangs tight until I can replace it.
the other thing that could be wrong with the drive shaft is if the u bolts that hold the u joint into the yoke are over tightened they will distort the caps. i will put blue lock tite on the u bolt nuts and tighten them while i hold the drive shaft with my hand. when i cant hold it from turning that is tight enough. i dont know how many times i find those too tight.
I did loc-tite and a lock washer, and quit tightening it when the washer gap flattened out. It wasn't tight, but tight enough. I did catch myself using the wrong u-joint once. O'Reilly said it was correct but all four caps were the same size, and two have to be larger, which I realized after being able tighten the nuts and still slide the shaft side to side about 1/16" each way. But someone has mentioned that issue above. I also swapped out the motor mounts, trans mounts, trans output shaft bushing, eventually a new transmission, had the drive shaft straightened and balanced, and new u-joints a couple of times. New balancer, new flexplate, changed the pinion angle 2 degrees, probably some other stuff. It was a lot of expensive fixes, but mine ended up being exhaust drone. At least I know everything else is aligned and balanced, now.
