Suspension Creak

[BrianE]

When driving on a bumpy or undulating road that excercises the shocks, the front suspension creaks as it flexes up and down. This is an IFS bus and I recently replaced the upper and lower A arm bushings and shocks which did not solve the problem. Am now suspicious of the torsion bar mounting bushings. Has anyone experienced this problem? Solutions?

[lonesome george]

Mine makes a noise like that after the bus has been sitting for awhile and I believe it is the sway bar mount bushings, it seems to get better after driving 500 miles or so. I'm going to take the mounting brackets off and make an attempt to lube the bushing bores with some type of snake oil and see what happens. The bushings on this bus look to be in good conditon but with two on each side it has a ton of surface area to make the rubber groan when the shaft turns in the bushing and I think that is what's making the racket.

[BrianE]

Thanks George. I removed one of them when rebushing the A arms and it was in such good shape I didn't replace them. Please pass on the formula for the snake oil if it works.

[GDeen]

Interesting post Brian - I had the same problem and after replacing all the sway bar bushings the problem was solved. Now I have a different noise. Only noticeable at very low speeds like going over a speed bump in a parking lot, whereas the prior creaking was most evident going down the road on dips that caused the coach to lurch up and down. A couple of weeks ago while at Prevost getting a Transmission service, I had the tech walk around under the coach with me checking things out. He noted the upper A arm bushings were going and said that would make noise......now here comes the question, he also said the bushings were not replaceable - had to replace the whole A arm assembly. Obviously if you were able to swap the bushings this is not correct?

Edit: Called Prevost and questioned the upper A arm bushing comment made by the Tech - he said it is absolutely replaceable, but they normally suggest replacing the entire piece as their labor for pulling it apart to replace the bushing makes it almost as expensive as a new arm.

[Kevin Erion]

Gordon, You must have a very special A-arm set up that is the only one! I did mine on my XLII and I would bet that you have the same A-arm. They must have an overstock of new parts that need to find a new home!

[GDeen]

Certainly what it sounds like Kevin. I told the tech that didn't make any sense to me, and meant to take it up with Ryan the service coordinator, but got off on another tangent and forgot to.
See edit to post above .....

[travelite]

Folks,

What is the life expectancy of the suspension A-arm bushings? (How many miles)?

Thanks,
Prevost Wannabe

[flyu2there]

Brian,

Get in there and squirt around some snake oil, and certainly not WD-40...try Aerokroil....it really does work!

[BrianE]

John, Thanks will try the Aerokroil.

David, My coach had approximately 100K when I replaced the bushings. Don't know if that's typical for an IFS chassis.

Gordon, Replacing the A arm bushings was a snap. It does however take an arbor press to do the job and two sets of hands is helpful also. I believe George came up with a tool that he built for Joe C. that allows changing them without using a press. I also had a bad ball joint in one of the upper A arms. Changing them requires a special fixture which is expensive. When I contacted a Prevost field rep to determine what is involved in replacing them, he advised replacing the whole A arm which the service centers do and which I also did. After reconsidering the project however it occurred to me that the service centers probably send them back to Montreal for a rebuild. And yes, ball joint rebuild kits are available. The cost difference is significant if you're doing the job yourself. Considering Prevost labor cost, replacing the entire assembly probably makes more sense to them.
Kit-Ball stud PN 611108, $65.84ea. Upper V-Link (A arm) with Lub points PN 611347 (old 611203) $381.75ea

[lonesome george]

David, I replaced the upper A-arm bushings at 42K (10 years) I think it is related to time and the amount of time the bus sits at the bottom of the suspension travel, at full bump. The lower A-arm bushings last longer than the uppers and I think it is bacause the upper arms are shorter than the lowers and at full bump tavel the angle of rotation is much higher on the upper arm, more twist in the bushing. The lower A-arm bushing has a larger diameter than the upper bushings and that reduces the rotational stress on that one. The rubber in the bushings I replaced was fractured and not dried out and I believe the fracturing is a function of father time and sustained rotation of the A-arm, IMHO.

How are you doing on the engine compartment detailing, super bling project? I want pictures!