[Richard]

I picked up 512 at Miami. Marc was nice enough to deliver it there because I wanted Newell to install a rear sway bar. First so all super thanks to Tuga for taking such great care of the coach. Thanks Marc for babysitting it till I had the chance to buy it It was even nicer thn what I remembered. Rhonda is very happy.

In addition the sway bar I asked Newell to put new tires on the rear. Yeah I know, advantage program would have been far cheaper but my local Michelin truck guy employs gorillas and I didn't like the way they handled the rims last time I used them. Plus I was looking at 800 miles of snowy weather and I wanted the best shoes I could have . Other than the normall Newell pace everything is great. I was able to take advantage of being over the pit to get a real good look under and install my toad brake line.

All is well until we hit the interstate in Joplin Hmmm. A low freq vibration that starts at 62 and gets stronger until about 72. This won't do for Mr OCD. So we turn around and head back. Test drive with techs confirms vibration. There is much discussion and theorizing about tires or sway bar being the culprit. Next morning sway bar is removed and test drive is repeated. The vibration is still there. That's kinda good because the sway bar makes a huge difference in the handling. Ok we check runout on the tires and one is out of spec. A deflate, spin 180, and reflate brings it in spec . We are really pushing the weather to get back home so we leave for the second time. Hit the slab in Joplin and no difference Stopped in Springfield and had tires spin balanced. No difference. Those of you who know my legendary patience are crying laughing right now. Stopped and pumped universal joints full of grease and it seemed to get a little better. I could feel a little slop in one of them just a tiny bit maybe a couple of thou. Stopped in St. Louis at Inland truck parts. A drive train specialist. Cept I picked the only shop that did not have a service bay. Oh yeah it's now sleeting and snowing at 25 degrees. They did loan me some specialized tools to get the drive shaft out. Three hours in the snow under the coach later I have it out. One bad diff, runout out of spec and corrected, and a spin balance gets me ready for the reinstall. 30 minutes tops! It's now fixed. Woo hoo! My apologies to the whole crew at Newell for putting them through the paces on the problem solving effort. They were real troopers. The winners prize goes to Pete who correctly Indentified it as drivetrain. So if you have a low frequency rumble / vibration at highway speeds it may be worth looking at the driveshaft especially if the frequency is 9.3 hz at 65 mph. Not that I used some high powered vibration phone app to find the root cause.

All the vibrating and driving has me reall tuned into the difference in road feel between 512 and 390. My theory is the two coaches have different resonance frequencies because of the difference in wheelbase and slides. Although the drive shaft fix cured the constant vibration , now that I am tuned to that frequency I. Oit e road imperfections cause the same resonance. It is a muc different resonance than 390