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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: someguy on September 26, 2021, 11:08:42 AM

Title: Why is the front axle so rough on this bus ?
Post by: someguy on September 26, 2021, 11:08:42 AM
The front axle on this bus seems to really jolt the bus when going over pavement cracks.   

This is an early 2000s Prevost H3-45.
https://youtu.be/jh5zGBM5kuA?t=344

Am I imagining this to be harsher than it seems in the video ?

Is this bus suffering from loose suspension bushings or worn out shock absorbers, allowing the axle to bottom slightly ?

Were the MCI9s with air beams smoother in this regard ?   

Are the IFS buses smoother ?   

Thanks
Title: Re: Why is the front axle so rough on this bus ?
Post by: lostagain on September 26, 2021, 11:45:15 AM
Even brand new Prevost H cars ride rough and harsh over rough roads, especially empty. The newer H3s have the IFS as an option, but they are rare, as it is expensive and most operators don't order them that way. That is why I prefer the MCI J because they come with the superb ZF IFS. Smooth as silk. Prevost, as good a coach as it is, is overrated in my opinion. I'll take a MCI anytime.
Title: Re: Why is the front axle so rough on this bus ?
Post by: chessie4905 on September 26, 2021, 12:10:57 PM
14,16,20 ply tires over potholes or really rough sections of roads at slow speed with 100+ tire pressure is harsh in any coach. Loaded to close to front axle max rating will smooth out a lot. Also loose kingpins, front end bushings, etc will also bang.Even in our 4104, hitting a smaller pothole at low speed could result in a stream of swear words. sort of like knocking fillings loose.
Title: Re: Why is the front axle so rough on this bus ?
Post by: someguy on September 26, 2021, 12:22:20 PM
Even brand new Prevost H cars ride rough and harsh over rough roads, especially empty. The newer H3s have the IFS as an option, but they are rare, as it is expensive and most operators don't order them that way. That is why I prefer the MCI J because they come with the superb ZF IFS. Smooth as silk. Prevost, as good a coach as it is, is overrated in my opinion.

IFS started on J4500s in 2014.  MCIs older than this have a straight front axle.    How do they ride in comparison ?

Prevost H3s have had IFS since 1998.   I wasn't aware that you could order them with a straight axle.  I thought they all had IFS.   The bus in the video is newer than 1998.   It should have IFS.   And yet is rides pretty harshly, from what I can tell, over those joints. 

MCI retuned the front suspension on the Js.   Here is the company that did the work.
https://www.randle.co.uk/case-studies/mci-renaissance/
Title: Re: Why is the front axle so rough on this bus ?
Post by: luvrbus on September 26, 2021, 06:29:18 PM
Tires don't help on a H-45 they are so front end heavy you need to max the air pressure anyways,I know it is a option on later H-45 for IFS but I never saw one yet. IFS has been around since 1996 on the XL our 1997 was IFS and was very,very exspensive to keep up that is why I got rid of it and went back to my old Eagle that had a trouble free IFS since 1958 
Title: Re: Why is the front axle so rough on this bus ?
Post by: Busted Knuckle on September 27, 2021, 08:12:25 AM
Tires don't help on a H-45 they are so front end heavy you need to max the air pressure anyways,I know it is a option on later H-45 for IFS but I never saw one yet. IFS has been around since 1996 on the XL our 1997 was IFS and was very,very exspensive to keep up that is why I got rid of it and went back to my old Eagle that had a trouble free IFS since 1958

Yup and since the Setra's and Eagles were both originally Kassboro  built Setra has always had excellent trouble free IFS too!
;D  BK  ;D
Title: Re: Why is the front axle so rough on this bus ?
Post by: someguy on September 27, 2021, 08:40:09 AM
Tires don't help on a H-45 they are so front end heavy you need to max the air pressure

Good point.  I wonder how much oversized steer tires would help the ride. 315s ?  335s ?  They would also give the front axle a bit more flotation in soft ground conditions.
Title: Re: Why is the front axle so rough on this bus ?
Post by: Busted Knuckle on September 27, 2021, 08:50:32 AM
Good point.  I wonder how much oversized steer tires would help the ride. 315s ?  335s ?  They would also give the front axle a bit more flotation in soft ground conditions.

You need to google them more!
Now days most Prevost come with 365's!
;D  BK  ;D
Title: Re: Why is the front axle so rough on this bus ?
Post by: buswarrior on September 27, 2021, 09:47:07 AM
You need to google them more!
Now days most Prevost come with 365's!
;D  BK  ;D

BK, the learning here is incredible!
Most of what I knew, turns out to be rubbish.
Even Cliff is learning things!
I look forward to every log-on for what's next.
BCM is getting almost as good as social media?

happy coaching!
buswarrior
Title: Re: Why is the front axle so rough on this bus ?
Post by: Utahclaimjumper on September 27, 2021, 11:50:03 AM

 BW,,, that's because your out in the sticks..>>>Dan  ::)
Title: Re: Why is the front axle so rough on this bus ?
Post by: someguy on September 27, 2021, 03:00:18 PM
Now days most Prevost come with 365's!

I did not know that, thanks for the heads up.   For the weight the front axle carries, they should be running 365s of the front.
Title: Re: Why is the front axle so rough on this bus ?
Post by: RJ on September 27, 2021, 04:00:59 PM
For the weight the front axle carries, they should be running 365s on the front.


Prevost has been running 365s on the front of their buses for the last five, maybe even 10 years now. . .

FWIW & HTH. . . ;)
Title: Re: Why is the front axle so rough on this bus ?
Post by: luvrbus on September 27, 2021, 04:16:02 PM
The 365 tire was made special for Prevost at 1 time Michelin was the only manufacture
Title: Re: Why is the front axle so rough on this bus ?
Post by: chessie4905 on September 27, 2021, 04:21:15 PM
go for a ride on a PrevostCharter bus and ride up front. then you'll get an idea.
Title: Re: Why is the front axle so rough on this bus ?
Post by: Busted Knuckle on September 28, 2021, 07:06:07 AM
I did not know that, thanks for the heads up.   For the weight the front axle carries, they should be running 365s of the front.

Yes the fronts were what I was referring too!
;D  BK  ;D
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