Monaco Tag Axle Trailing Arm Break

[EBROG]

I just completed a cross country trip to California. About 80 miles from my destination I pulled in to fuel up. I noticed something unusual about the trail axle wheels, they were slightly bowed out. I raised the axle which somewhat helped while I limped into my destination. I took the attached photos which show the breaks in the metal on both sides of the coach. Is this something that can be fixed such as welded, or does it require replacement? I appreciate any help or suggestions you can provide.

Roger

[hermanmullins]

Rodger,

Welcome to the Forum.

Sorry for your problem. Are you speaking about your tag axle? There was a recall on the single axle but not on the tag. The unfortunate thing is that the recall was when Monaco owned the company but since it has changed hands the warranty on the older units are not applicable. You mentioned pictures but none were attached. Can you post them. It will give folks a chance to give better answers.

Herman

[wolfe10]

Herman,

Yes, the issue with trailing arms was on the 4 air bag Monaco suspension. Unrelated to the trailing arms on his 10 bag suspension.

Roger,

OK, the engineer who designed the 10 bag chassis now has his own company. I would contact him-- may be tough in the short term, as I believe he is down at the Monaco Rally in Coos Bay, Oregon right now and will be at the FMCA Convention in Redmond next week.

Scott Zimmer

http://www.rv-chassis.com/about_us.html

[EBROG]

Thanks! Yes, I meant the tag axle. This has got me flustered to say the least. I'm just glad the wheels didn't come off while I was on the road.

Let me know if the picture comes through.

[hermanmullins]

Roger,

From what I an see there was a metal failure and not a weld. It looks like the fracture is in the rectangle tubing. Can you see if the fracture is fresh or does it look as if has occurred over time? Such a break can be repaired but it will take a very good welder along with good dimensions and drawings. Please be sure to look at the other side for signs of structure failure there also.

Like many things I wonder what caused a failure. You can replace a blown fuse but what caused it to blow. A structure like yours can be repaired but what caused it to fail in the first place.

Find Scott Zimmer and see what he has to say.

Good luck and glad there was no more damage.

Herman

[wolfe10]

I took the liberty of contacting Scott-- sent him a link to this thread.

Here is his reply:

Hello Brett, I've seen several of these tag assemblies break at the driveline cut out, the later coaches had a tag axle that had a hump in the middle so the axle would not need to be cut and the center section welded in for this very reason. The fix is to get it back straight re weld and ad some additional structure in that area to beef it up that's all you can do

Also, this guy needs to make sure the tag air pressure regulator is working properly and adjusted properly if the tag is loaded to heavy it makes the problem worse.....Scott

[billbaldwin]

This looks like a failure in the heat affection zone from the original weld.

You should not square up and re-weld (IMHO).

A good welder can rebuild.

A good pre-heat procedure or post weld heat treating will be required.

[kebowers47]

I would replace the broken metal section--cut it out, replace with one wider and thicker.and high strength steel, not scrap iron. An easy job for a GOOD metal fabricator . Cut the old one out with ?? plasma torch. Re-weld with MIG. PWHT with oxy-acet torch with rosebud tip. What the picture tells me is this was a progressive 'fatigue' failure starting from a brittle spot in the weld affected zone. Getting a good weld etc might require removing the part from the coach for access.