That distinctive loud scream would never get old, sounds amazing on any bus but especially DAF DB250’s. Shame times change and it’s now rarer to find these brilliant sounding beasts.
As a driver I LOVE the DIWA’s retarder as it’s SO powerful compared to ZF’s or Allison’s. It’s engagement is a wee bit ‘rough’, however. At least compared to the others. But THE SOUND 😍😍😍
Yes, I feel sad about that. They used to be common here in Portland, Oregon when Tri-Met first specified the Voith in its 1988 Flxible Metros numbered 500-549.
@@busspotterbg2459 takođe, mi u Rijeci imamo Conecte i Classice sa Voith getribom. Samo steta sta nema vise Avtomontaza jer si prije mogo njih cuti na kilometre
@@jamesfrench7299 Yes, I too wish to know about that unique whine that rises when you hit the throttle. I know the Renk 870 series used in the earlier MAN buses operated in much the same way.
@@aa44tc34 En tout cas dans un NovaBus LFS on entend TRÈS BIEN la Voith. Dans nos bus articulés j’entends presque pas le moteur alors que je suis au volant, mais la transmission? OH QUE OUI 😍
If you mean the whoosh when it slows down. That is the force of the dynamic brake controller initiating the magnetic brake retarder. Dynamic brakes were first used on trains but now most buses since the 1970's have it to reduce wear on the brake pads :). Hope this helps.
Basically, the gearbox selects the reverse gear set and the resulting low ratio spins the torque converter at a very fast speed in the opposite direction. At least that's how I understand it.
If you are referring to the noise from 0:38 to 0:51, that is the hydrodynamic retarder. Most turbines make a whistle or whine sound when spun at high speed. Since the retarder is comprised of a stator and rotor (the torque converter’s impeller & turbine, in this specific case) this is what generates that noise as the turbine is rapidly accelerated to high speeds once the retarder engages. The rest is simply “normal” transmission noises. All gears make noise when meshing together. Straight cut are the noisiest. Not too sure which type Voith uses in the DIWA. 🤔
I think it's the "first gear" gearset spun over in the reverse direction at a crazy-high ratio. Voith do have a video explaining the principle behind it.
All gearboxes make some kind of whining noise, with automatics it's mainly the oil pump, torque converter, retarder and gears you're hearing. Then the housing resonates at different frequencies depending upon the gearbox design, and for example ZF 5HP50x gearboxes sound like ordinary car manual gearboxes while Voith DIWAs 85x sound more like gas turbines. Maintenance plays an important part too. I just replaced gear oil in my car's manual transaxle (with OEM GL-5 oil, same one used in buses ZF rear axles actually) and found it now sounds a little ZF-like louder than it used to when the 20 year old factory fill was still inside (perhaps it thickens away with age and use and then dampens vibrations in a better way). Perhaps the loudest Voiths have just had the old ATF oil flushed and replaced but i could be wrong
@@jaggass Personally, i enjoy loud Voiths more than ZFs. I've too heard pretty silent ZFs or Voiths, on really old buses mostly. To the point i even wondered if the Voith bus had a Voith at all. What i really hate, however, is the deep moaning/groaning/humming noise that rear axles (probably the reducer part, that cylindrical shaped thing where the gearbox output shaft meets the axle so that wheels are driven) seem to create on some buses (awful soundproofing perhaps). This one will follow rpms, make the floor vibrate and cover/ruin any ZF or Voith gearbox noise pretty bad. Pretty sure about the origin, since i've heard the same noise whether the same bus model had a ZF or a Voith, and it's clearly not a power steering or cooling fan noise.
Im a bus mechanic. We have Voiths in our new buses. You guys are strange. The only sound I hear is cha-ching! The configuration we have is gonna be overtime for R&R & servicing
@@user-ck8is5mn9m Ovo što ću Vam proslediti, nije baš direktno IK-202, ali je mehanički identično. Raba D10 (doduše, od 160 KW, slabiji od onog u IK-202), Voith sa tri brzine i Raba BDI pogonska osovina. A čini se da je i sam autobus u dobrom stanju. Audio snimak (pažljivo gledajte naslov i opis videa) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CiWDacsIaRA.html Video u enterijeru istog autobusa ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JfefYgACVV4.html ENG: This, what I am forwarding to you, isn't quite an IK-202 directly, but it is mechanically identical. Raba D10 (although it's a 160 KW version, less powerful than the one in the IK-202), three-speed Voith and the Raba BDI driving axle. And it also seems that the bus itself is in good condition. Audio recording (watch the title and the description carefully) - *adress* Video from inside the same bus *adress*
