Used Class C -- Rattle upon deceleration

[atarsha]

Hello All!

My wife and I recently bought a used 2003 Fleetwood Tioga SL 31 foot Class C. On our current trip, we noticed a noise, I can best describe as a rattle/very slight grinding noise only when decelerating at around 55-65 MPH. No noise is heard while accelerating or maintaining speed.

I first thought it was a loose exhaust heat shield, so I checked those very thoroughly. I then greased the U-joints, and although there is no zerk on the driveshaft support bearings, I packed grease around them the best that I could, but doubt I really got any inside them.

From the drivers seat it sounds like it's directly over my right shoulder on the floor, but my wife believes it's further back near the rear axle.

I know diagnosing noises based on online descriptions is difficult, but I'm not having much luck myself here. Any suggestions? We are away from home by thousands of miles, so I'd love to track this down before having to make the trek back.

Thanks for any suggestions you may have.
-Alex

[pnichols]

John,

Wish I could help you ... but I haven't got around to it yet ... sorry. We're in the middle of a major home remodel and have other projects, plus we must live in our motorhome in the back yard for awhile the rest of the summer.

This noise seems "harmless" but irritating. We don't hear it at highway speeds and not always at lower speeds. It doesn't seem like this noise should affect your selling of the motorhome. The sound sure sounds like some shroud around the motor has come loose ... probably a screw somewhere has fallen out holding one corner of it in place.

Have you pulled off your doghouse and poked around the motor yet? Maybe you can help me! :h

[Jaward]

Hey pnichols I have the same noise with my coachman 3150 SS and have not been able to fin it. Metallic sound from floor area between the two front seats. Intermittent noise at different speeds. Will do it at low speeds or at high speeds.

Rough roads make the noise more often

Can't figure it out

I'm in the middle of selling it and can't figure it out!!!

Please help

Thanks

John

[Cousin_Eddie93]

I have the same issue on my 1993 29' ford chassis e350 but I'm almost certain its center differential U joint. I lubed it up last year and noise decreased but not totally. A family mechanic said its a common ford thing and that I would need to replace it if the sound increases. He said its fine for now. The rattle noise is rather minimal and mostly occurs at low speed before or after gear shifts.

[woodgeezer]

atarsha wrote:

woodgeezer wrote:
You don't say what chassis you have, but I would have the drive shaft professionally checked. I experienced a similar "rattle" on two Fords I owned and had a warn rear u-joint on one and a bad center bearing on the other. Just checking the fit by hand is not the same as doing a fine inspection without load. Cheap check and easy repair.

It is the 2003 Ford E450 Cutaway Chassis, I'm not sure if that's the detail you're looking for? Also, where might I take a 31 foot RV to have that checked? A general mechanic, an RV dealership? (Especially considering we're living in it now.)

I have used a company called SLYCO http://www.slycodrivelines.com/ in Salt Lake. Because your rattle is speed related and not universal when decelerating, I'd check with them. Semi Service in Salt Lake and Six State Supply could also help. I know Slyco does a lot of commercial vehicle work, and was the last place I had work done on a vehicle where the quote was spot on, on time and under $100. Can't beat that.:)

[bobm253]

Mine was broken baffles in the muffler. Also could be pinging on deceleration.

[atarsha]

cgmartine wrote:
There is a rectangular metal plate about one and a half feet long that is located above the muffler, close to where the muffler ends. This plate protects the plastic storage compartment from being melted by the muffler. The plate has a couple of hangers, which if broken, will allow the plate to make contact with the muffler, creating a rattle. This rattle is possibly being transmitted all the way up to the manifold at certain speeds. It can't hurt to check.

I didn't find any such plate, but in looking I did find a loose exhaust hanger that I missed before. I wont know for awhile if tightening it fixes the problem, but I'll make a note to fix that before I head out again. Thanks.

I am still open to other ideas as well, I can't be certain the one loose hanger is the cause.

[cgmartine]

There is a rectangular metal plate about one and a half feet long that is located above the muffler, close to where the muffler ends. This plate protects the plastic storage compartment from being melted by the muffler. The plate has a couple of hangers, which if broken, will allow the plate to make contact with the muffler, creating a rattle. This rattle is possibly being transmitted all the way up to the manifold at certain speeds. It can't hurt to check.

[atarsha]

othertonka wrote:
I would check for loose baffles' in the cat convertor or mufflers

Wouldn't both of those make noise outside of 65MPH and outside of only during deceleration?

[atarsha]

j-d wrote:
Is the Rear Axle (Differential) Lube full?

It is. Just below the bottom of the fill plug. I checked it while on the road, so I didn't inspect it very thoroughly, but I do remember thinking it was a bit dark. Not sure if it's supposed to be.

[othertonka]

I would check for loose baffles' in the cat convertor or mufflers

[j-d]

Is the Rear Axle (Differential) Lube full?

[Handbasket]

Your best bet may be a truck mechanic for what's apparently a chassis issue. For the little that I don't DIY, my mechanic operates in a truck tire shop, mostly doing alignments but also brakes & such as needed. Our Chevy dealer has a truck shop too, as do some area Ford dealers.

Jim, "There's a fine line between 'hobby' and 'mental illness'."

[atarsha]

woodgeezer wrote:
You don't say what chassis you have, but I would have the drive shaft professionally checked. I experienced a similar "rattle" on two Fords I owned and had a warn rear u-joint on one and a bad center bearing on the other. Just checking the fit by hand is not the same as doing a fine inspection without load. Cheap check and easy repair.

It is the 2003 Ford E450 Cutaway Chassis, I'm not sure if that's the detail you're looking for? Also, where might I take a 31 foot RV to have that checked? A general mechanic, an RV dealership? (Especially considering we're living in it now.)

[woodgeezer]

You don't say what chassis you have, but I would have the drive shaft professionally checked. I experienced a similar "rattle" on two Fords I owned and had a warn rear u-joint on one and a bad center bearing on the other. Just checking the fit by hand is not the same as doing a fine inspection without load. Cheap check and easy repair.