Front end making more noise over bumpy roads

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Front end making more noise over bumpy roads

December 08, 2020, 11:31:40 am

2003 U295 90K miles Tracking fine, barely need hands on the steering wheel.

On our last trip from Santa Rosa, CA to Congress, AZ I was feeling and hearing more noise than I was used to.

Mostly a good clunk over expansion joints and on patched roads.

FOT had checked king pins in 2018, and I had new front wheel bearing installed in 2019 (noise was there before too)

I've searched and can't locate a diagram/parts on the front end assembly. My first guess is there're some bushings somewhere that need replacement, or something. I called the Motorcade "hotline" number, they sent over Meritor front axle parts diagrams? (king pins etc) no FT application listed.

Thanks in advance, Paul

i

Re: Front end making more noise over bumpy roads

Reply #1 – December 08, 2020, 12:42:40 pm

Shock bolts might be your issue. The front end parts usually go over 100k.

Re: Front end making more noise over bumpy roads

Reply #2 – December 08, 2020, 01:36:24 pm

Quote

Shock bolts might be your issue. The front end parts usually go over 100k.

I had the same problem on one of our rigs. Just a loose shock making lots of racket.
In my limited experience, at 100K there is no noticeable wear in the front end parts. My current rig is at 165 and still tight.
jor

Re: Front end making more noise over bumpy roads

Reply #3 – December 08, 2020, 01:44:03 pm

I agree check your shock bolts.

Re: Front end making more noise over bumpy roads

Reply #4 – December 08, 2020, 03:03:45 pm

Could be a bushing in the trailing arms or panhard bar.

Mike

Re: Front end making more noise over bumpy roads

Reply #5 – December 08, 2020, 05:50:44 pm

I have a clank that is only noticeable at slow speeds and rough roads. I believe it is this part that is causing the clank.

Mike is this a "panhard bar"?

Re: Front end making more noise over bumpy roads

Reply #6 – December 08, 2020, 08:01:40 pm

Check your shocks foe a loose or broken bolt.

Re: Front end making more noise over bumpy roads

Reply #7 – December 08, 2020, 08:14:30 pm

Quote from: stevec22 – December 08, 2020, 05:50:44 pm

Mike is this a "panhard bar"?

Yes.

Mike

Re: Front end making more noise over bumpy roads

Reply #8 – December 08, 2020, 08:41:38 pm

Quote from: stevec22 – December 08, 2020, 05:50:44 pm

I have a clank that is only noticeable at slow speeds and rough roads. I believe it is this part that is causing the clank.

Mike is this a "panhard bar"?

Yep, I agree Steve

Re: Front end making more noise over bumpy roads

Reply #9 – December 08, 2020, 08:45:54 pm

I had a similar noise to what you descibe in my FT.. I was traveling on to a hwy and had to go 15 miles at 35 mph as I thought for sure something was about to break. After hiring a mobile mechanic and truck alignment shop to find the noise, I could not believe this steel rod (a large 12 inch socket extension) under a slide tray was echoing up into the rv as it did, and made a sound similar to a broken shock mount.

So my advice is to yes, perform a safety check of front suspension components and if nothing shows up, check your basement area thoroughly for anything similar to my issue that could be making that noise.

Re: Front end making more noise over bumpy roads

Reply #10 – December 08, 2020, 09:07:53 pm

Steve,

I have the part number for those Hutch bushings out in the camper and will look it up tomorrow. They are made out of rubber so they have a limited life. They now make an upgraded nylon that are a big improvement. I will find that part number also.

Mike

Re: Front end making more noise over bumpy roads

Reply #11 – December 08, 2020, 09:08:39 pm

Quote from: Pamela & Mike – December 08, 2020, 09:07:53 pm

Steve,

I have the part number for those Hutch bushings out in the camper and will look it up tomorrow. They are made out of rubber so they have a limited life. They now make an upgraded nylon that are a big improvement. I will find that part number also.

Mike

Mike,
Thank you

Re: Front end making more noise over bumpy roads

Reply #12 – December 08, 2020, 09:42:12 pm

Check the red rubber donuts at the bottom of the generator door. I had the clunk, red donuts were grooved...loosened the center bolt, rotated the donuts, tightened the bolt....clunk is gone.

A lot cheaper than replacing the front end parts.

Woody.

Re: Front end making more noise over bumpy roads

Reply #13 – December 09, 2020, 08:59:25 am

Steve,

OEM the bushings should be Hutch RBT-201 which are pretty much an industry standard. The Hutch Polyurethane PL1119 are a supper upgrade. Yes at ~$35 a set they are pricy but you don't have to replace all at the same time. We have Truck part world here that has either Truck Parts World | Quality Parts Since 1987 any good heavy truck parts store will be able to help out. One thing that you should know is never mention RV or Foretravel. Just take the panhard bar or torque tube and put it up up the counter and tell them that you need some replacement bushings.

There are some discussions in the past that gives more detail so you might do a search for more info.

Mike

Re: Front end making more noise over bumpy roads

Reply #14 – December 09, 2020, 09:39:17 am

I had a banging noise up front whenever encountering bumps in the road. I looked at every possibility including the upper shock mount bolts, to no avail. But when I finally put a impact gun on those top shock mount bolts the noise magically disappeared.

That is where I would start.

Re: Front end making more noise over bumpy roads

Reply #15 – December 09, 2020, 10:01:32 am

Is there any difference between the two in regards to ride and noise ? My previous history with Polyurethane bushing always transfer road noise and could never get them to stop squeaking when in motion. Do Hutch Polyurethane PL1119 PL1119 by ATRO - Torque Rod Bushing
perform the same in comparison to the stock rubber bushings?
25-708 by POWER PRODUCTS - Torque Arm Bushing-OD = 1-29/32", ID = 1", L = 3"
I really don't know the status of my original bushings but I'm sure they are at the end of their life at 60k miles and 20 years old.
Scott

Re: Front end making more noise over bumpy roads

Reply #16 – December 09, 2020, 10:07:39 am

My u-joints in the steering shaft make this noise on washboards but the mechanic says they are fine

Re: Front end making more noise over bumpy roads

Reply #17 – December 09, 2020, 10:46:50 am

Redid all my torque rods over the years,had to cut a few of the 1 inch bolts in 2 places to remove,got the same hard rubber bushings
from Foretravel,you can find the nuts and bolts at Fastenal.I would be leary of the polourethane over the stock rubber,may be
great for a 50K trailer but rough on a Foretravel,you can check them easily with a pry bar,if any play they are worn.Anyone tackling
this themselves I'll be glad to talk you thru the process.Never thought a noisey u-joint is fine.

Re: Front end making more noise over bumpy roads

Reply #18 – December 09, 2020, 11:02:00 am

Quote from: John44 – December 09, 2020, 10:46:50 am

Never thought a noisey u-joint is fine.

Yeah, loose or worn u-joints cause vibration that can be felt.

Re: Front end making more noise over bumpy roads

Reply #19 – December 09, 2020, 11:08:00 am

The Rbt201 and the PL1119 are 2 entirely different assemblies,the RBT201 style (one piece) is not what Foretravel used (at least in
mine) my coach has the PL1119 style only with black hard rubber, the rubber pieces have a shoulder that buffers between the round
side ends of the rod and the mounting flange to help with side to side play,anyone needing another opinion try checking with
James Trianna at Foretravel.

Re: Front end making more noise over bumpy roads

Reply #20 – December 09, 2020, 11:40:26 am

Quote from: dsd – December 09, 2020, 10:01:32 am

Is there any difference between the two in regards to ride and noise ?

I like the polyurethane bushings as I haven't noticed and difference in harshness of ride or noise.

A lot of steering related problems are miss diagnosed as bad steering sector, tie rod ends, tire pressure, wheel bearings, or alignment of the front end. True all of these can cause steering wander and should be checked. The thing is most places don't even look at the torque rod/trailing arms or panhard bar bushings. Due to the geometry of these coaches if these bushings have too much slop it will cause the coach to run doglegged down the road and due to oscillations in the road cause sawing on the wheel effect. Trying to keep this simple the panhard bar lets the axle move vertical and centered under the frame ( this is another reason the ride height is important to be set proper) so with bad bushings the axle can move side to side depending on the slop and arc of panhard bar. A lot of times this is thought of as a shimmy effect.

The trailing arms locate the axle in relation to the length of the coach. If these bushings are sloppy then you can have the dogleg effect. Think have you ever came up behind an 18 wheeler and could see the side of his box from behind? He is running dog legged and this can happen to these coaches when one side of the axle is further forward/rearward than the other side.

Now this isn't here to as an all inclusive education on frame alignment just a simple brief answer some questions that have been sent my way. If you want more info the Hunter truck alignment school is pretty good.

Mike

Re: Front end making more noise over bumpy roads

Reply #21 – December 09, 2020, 12:32:50 pm

When changing these out. Are the Pan hard bars under tension/ compression? ie do they need to be restrained before pulling the bolts? Will the frame "rack" causing problems when reinstalling?

Re: Front end making more noise over bumpy roads

Reply #22 – December 09, 2020, 01:02:28 pm

You do one at a time and you will probably have to raise/lower the coach during the job and remember to put the new bolts back in
the same direction as the old ones to make a removal easier.

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