Vibration

I developed a vibration & I cannot tell if it is coming from suspension or drive train, u-joints, trans, e.t.c. I get a heavy vibration when in 9th gear at 1400-1600 rpm's. the vibe is also present in lower & higher speeds but most noticeable in 9th. the truck idles good. top end rolls fine, when in 9th I'm at aprox 45 m.p.h. I took truck out of gear & put in neutral to coast & see if any difference & no difference, still heavy vibration. I was thinking if it was in the drive train, the vibe would go away when put in neutral. since it does not, I think it is in the suspension somewhere. tires, air bag, e.t.c. I know it is not my leveling sys. that I know for sure. the vibe is really strong on my steering wheel & shakes my mirrors. any suggestions.

 

It shakes up & down.

 

I also have centramatics & they have been great. no irregular wear.I do not hear any noise & the rims do not even get warm after a long run, so I thought wheel bearings are o.k. could spring hanger bushings cause this. they have never been replaced. 15 year old truck.

 

oh' and I took it to 2 reputable tire co, 4 months ago t.c.i. which is owned by Michelin & mgriff tire co. both said front end is tight, can't find anything. had new steers put on & 3 axle alignment with the centramatics at t.c.i .aprrox 95,000 milles ago 10 months thereabout.

 

thanks for the replies.truck is at local shop now. not sure if they can figure out what the problem is. I had one of the mechanics go with me for a ride & he said he can feel vibration under his feet. he thinks it may be in the u joint area maybe too much slack, but he will not know until he looks further. mentioned he will also look at motor mounts. I myself am leaning towards the spring hanger bushing. years ago when I had a problem with the drive line I would throw in into neutral & the sound would go away, which told me it was in the drive line. had that fixed 8 years ago. coasting now does not alleviate the problem, so I am thinking suspension, cause suspension is under stress no matter torque on drive line or not. I hope to have a diagnosis today. will post here when prob solved.