Vibration witchhunt - Printable Version
+- Newell Gurus (https://newellgurus.com)
+-- Forum: Technical Discussions (https://newellgurus.com/forumdisplay.php?fid=3)
+--- Forum: Suspension/Tires/Wheels (https://newellgurus.com/forumdisplay.php?fid=5)
+--- Thread: Vibration witchhunt (/showthread.php?tid=1264)
+- Newell Gurus (https://newellgurus.com)
+-- Forum: Technical Discussions (https://newellgurus.com/forumdisplay.php?fid=3)
+--- Forum: Suspension/Tires/Wheels (https://newellgurus.com/forumdisplay.php?fid=5)
+--- Thread: Vibration witchhunt (/showthread.php?tid=1264)
Vibration witchhunt - Richard - 02-14-2014
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
RE: Vibration witchhunt - bikestuff - 02-14-2014
Richard,
Was the vibration something that you felt or was it more like a noise? I pilot friend of mine said that his most important instrument was his butt! (He was talking about how the helicopter felt in the seat rather than what the instruments say).
I assume that the vibration was speed specific, and did not relate to how hard the engine was working?
I have only ever ridden in one Newell and that is the one that I have driven for almost 40k miles. I am not sure what it is that I am supposed to listen for.
RE: Vibration witchhunt - Richard - 02-14-2014
I felt it in the floor, more so than in the steering wheel. I intentionally shifted gears to change the engine speed to decouple engine rpm from speed in the witchhunt it did not track the engine rpm
RE: Vibration witchhunt - Fulltiming - 02-14-2014
Congrats on getting Tuga/Marc's coach Richard. I always liked that coach.
RE: Vibration witchhunt - Airplane Guy - 02-15-2014
I admire your tenacity Richard, well done.
RE: Vibration witchhunt - qcj - 02-15-2014
Richard, I have only driven one Newell and it is the one I have now and it drives so much better than any of the 6 MHs I owned before. I do not have a rear sway bar and am thinking maybe having one installed next time I'm at Newell. I called Newell last week and was told that they didn't install rear sway bars until late 04s when they install the new type of rear axle?? Steve said his 99 looked like it came from the factory with a rear sway bar, because of the way it was installed with welds and factory insulation on the bar. How was yours installed? Did they use U bolts or welds and was it fairly expensive to have done? There is no doubt that you certainly recommend having one installed, but did you drive 512 before one was installed, and if so is there a lot of difference?
RE: Vibration witchhunt - Chester Stone - 02-15-2014
Richard, when you get a chance, how about posting some pictures of your new rig.
RE: Vibration witchhunt - Richard - 02-15-2014
Chapple
As part of the problem solving effort we removed the sway bar. It made a huge difference in the side to side tippy feeling Count on two grand and up depending on what they run into. Lots of welding of 3/8 steel plates for mounting of the bar. There was lots of reinforcing to handle the forces after seeing it done it would have been way over my head it is definitely not a bolt on. It looks to be about 1 3/8 diameter. It's massive. I think it was money well spent and I would do it again.
RE: Vibration witchhunt - qcj - 02-15-2014
Thanks Richard, and I'm sure you will enjoy your new coach.
RE: Vibration witchhunt - qcj - 02-16-2014
Just drove my coach about 75 miles home from a 4 day campout with our local club. About half was on two lane roads and other half on 4 lane. I really have no issue in the way it handles. I got to thinking on the way home that maybe coaches with rear baths might have more of a problem. The baths have got to weight twelve to fifteen hundred pounds and with that much weight at the rear of the coach might cause more of a sway than with the bath in mid-ship?? Just a thought. Also the tag has to give us a little stabilization on these longer coaches. It is sort of like going to the eye Dr. You feel you can see just fine and then when fitted with a new set of glasses, wow I just thought I see just fine. Soooo it come down to weather or not one wants to risk a couple of grand to see if you might like it better, when one is already happy. One good thing about it is if I should feel like it does have side to side tipsy feeling it can be fixed.
Forest and Chester has about the same lay-out in their coaches as I do and they might already have rear sway, I don't know, but if they don't will they please let me know if they had an issue in the way their coach drives.