Chinook RV

Before you say duh, let me state there are no ride indications that I need new shocks. Could this happen if bottoming out? I know I've slowly scraped the rear end getting out of some parking lots maybe two or three times at most. The fiberglass had small spider cracks when I bought it and after 6k miles it looks like this.

Hmm, that's interesting. I have bottomed out a time or two coming out of gas stations with a big "lip" but that has resulted in the very bottom of the trailer hitch scraping -- which makes sense as that is what hits first with our "bad" departure angle on the Chinook (due to long overhang). I can't see hitting the tailpipe in any typical situation.

So let me ask a question: What does it look like on the inside of the fender there? This could provide a clue to what's going on. One thing about cracked fiberglass is that it's usually not too hard to trace what's going on once you can see the whole situation.

Thoughts:

1) Has someone put some sort of exhaust bracket between the tailpipe and the fiberglass shell (there shouldn't be anything like that).

2) Is, as you mention, anything in the suspension allowing the tailpipe to rise up when you go over bumps? Obviously this wouldn't normally happen, so is something worn or improperly installed?

3) What happens if you grab the tailpipe and give it a shake?

4) I don't think a typical scrape would touch there (and evidence is saying that whatever is causing it is happening repeatedly, not just one odd time, so I don't see it being hitting one odd rock or etc).

Here is a crop of the tailpipe area on my rig, looking forward. As you can see it does not attach to the body shell at all.

This looks a lot like the damage I got when pulling out of a site with curbing. But mine has more damage. The tail pipe hit on the curb and was shoved into the body. I had to push the the tail pipe back down as it had pivoted on a clamp forward of the bend. Mine has the Banks exhaust, but I'm betting yours is similar.

Larry
1999 Concourse

When that happens, are there marks on the bottom (ground) side of the tailpipe as evidence? Not that I doubt you, but wondering if the OP could check for that as a clue.

I just looked at the underside and nothing looks unusual to me. When I give the pipe a good shake it has very little movement. It feels nice and tight and the underside of the tailpipe doe's not have any scrapes. I tried to pull the pipe up to see if it would touch the body and it won't. Hmm?

Well I probably didn't describe what really happened very well. More from trying to save typing than embarrassment, or maybe not

I actually hung up the rear bumper on the rock retaining wall for the pad I was parked on. When pulling out I cut too sharp. Had to get some boards and jack up the axle to get enough traction to drive off it.

When I pulled off the bounce was so that the body bottomed out on the axle pads which allow it to hit the exhaust hard enough to break the fiber glass. The exhaust was stuck in the fiberglass and I had to put a bar in it to pry it back down.

yikes...

I don't see anything odd and I didn't see any special suspension systems. Thanks for the ideas. I'm going to have the spouse drive for the oil change and I'll drive along the side to see if I notice anything. I want to get the cracks fixed after I figure out the cause.

Possibly a stupid question... is the clearance between the axle and the exhaust pipe less than the clearance between the axle and the bump stop?

Scott,
I'm pretty ignorant when it comes to automotive terms such as bump stop but I do have additional information. I believe Blue asked how the exhaust pipe felt when I give it a good shake, I replied it felt tight. Today, I laid on my side and put my elbow on the ground and pushed up on the pipe and it moved enough to hit the fiberglass. I was pushing reasonably hard, so it must need a good 'slam' on the road to move it toward the fiberglass. I'm taking it in for servicing next week and I'll have the guys check the exhaust hangers. It appears if it was lowered a little I wouldn't have a problem.