RE: the harmonic thingy post

I read a while back the post about the harmonic modifier thingy mounted on the propshaft of vertian models of range rovers i think.

Now i dont actually own a landrover or owt, just building a motorhome on an Iveco daily van,

But i liked the description of this thing, i.e to adjust the harmonics of the propshaft/rotating mass of the drive train to a frequancy not likely to be encountered in normal driving,

I've had the diff re-placed on my van, and will be having the propshaft re-balanced when i can find a place to do it, (it's the extra long wheel base van, something like a 4 meter long shaft, 2 centre bearings, couple of sliding joints and so on)

Anyways, i have an anoying hum at certian speeds, and it's down to the propshaft/drive train from the box to the diff, and apparantly even after i have the shaft re-balanced, i'll still get harmonics at certian speeds, seems the turbo joins in at about 72 mph and maked a pulsing harmonic when combined with the propshaft one (let off the loud pedal an inch so the boost drops a few psi, and the pulsing harmonics go away, but it dosent do it at any other speeds in other gears when at the same boost, it's deffo something to do with a few things making frequencys that are coliding with each other, and making my ears hurt :)

Anways, what exactly does the harmonic modifier thingy mount to?? is it the prop shaft, the diff, i read that it fall off every now and again, so i imagine it dosent go around the shaft,

you can guess that i want to fit one to my van if i can, (i have always done that kind of thing, if i like something another vehicle has, i'll try and get it and make it work with my van, hence the self build coachbuilt, i've taken all the best parts i like from about 20 different motorhomes, and am building one that has everything i want, and nothing i dont :)

oh, i'd best ask if anyone knows how much they go for too, and what models they are fitted to, there's a few rangies down the scrapper, but unless i know what model i'm looking for, and roughly where to look, i may come away with the wrong thing (ok, so an exhaust brake or telmar brake would be a nice thing to come away with by mistake, but i dont think range rovers had em.. do 101's by any chance?? :)

Reply to
CampinGazz
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On the Disco it's the steering bar, although my memory could be playing tricks on me here. I guess a toroidal one around the prop shaft could work if you could balance it properly, but I think it would do more harm than good.

You could easily experiment by clamping different masses of metal to different (non-rotating) bits of your van. Just make sure they have no chance of going through somebody's windscreen :) There's nothing specialised about the Land Rover one, it's really just a lump of steel.

David

Reply to
David French

"CampinGazz" wrote in news:brdkma$3rg$ snipped-for-privacy@hercules.btinternet.com:

I think the article you want may be one in Land Rover International June Issue 7 2001. If you phone the Back Number Department (sorry, don't know the number but they must have a web page) they may be able to supply a copy. The article is "Bad Vibrations". If you can't get a copy, email me and I will send you mine.

Derry

Reply to
Derry Argue

What you're trying to do is change the resonant frequency of the part, so a metal ring around the shaft would do something. But you'd still have to balance the shaft, and I've no idea how much difference it would make.

I know one buzz, on one vehicle, is the gear lever.

Reply to
David G. Bell

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