Hitch failure on 2015 Siesta

[mnapier49]

Originally Posted by Winterbagoal

The specs I found were based on a guess as to which specific model you had. You weren't specific in your OP, and so I guessed that it was the lighter weight unit on the Sprinter chassis, based on the damage visible in your picture. Not the one on the Ford chassis, which is probably rated at 5,000 lbs. at the hitch drawbar.

The chassis is Mercedes not Ford.

[AC Orange]

Originally Posted by mnapier49

I still have Thor's equipment sticker which lists the Standard Equipment on the vehicle at 5000lbs which was the reason we did not go with the same floorplan on Coachman's version which listed the hitch rating at 3500lbs.

.
Well, after all is said and done you've got documents showing a 5k weight rating. And I've been restoring antique cars and tractors for 45 years and done welding on all sorts of frames, etc. and looking at that photo, it's pretty clear that the weld on that frame section is garbage. You should definitely turn that into the NTSB. I wonder if there have been any other failures reported on that unit ? That sort of thing is a real catastrophe waiting to happen for the owner and anyone driving around that vehicle.


Yet another example of the shoddy quality the RV manufacturers are churning out these days.
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[Hooligan]

Just looked the hitch on my 2016 Siesta Sprinter. Same hitch/frame. Photo is the bottom of a heavy 9 inch angle iron frame that is torn . Hitch moved down and forward. (hard braking?) From the rust this metal had been cracked for some time. The only weld is the short box section at the rear of the frame.
The hitch is rated at 5000#. My Suzuki toad is 3400# and my hitch assembly shows no damage or rust..

I understand that the frame extensions on the THOR Sprinter chassis' are done by MOR/ryde

[mnapier49]

We were braking at the time as we were just exiting the freeway (very lucky), but I wouldn't say hard braking. Yes, the only welds involved are the end caps, however, my son (Structural Engineer) said that the end caps were critical to this particular design, especially considering the gauge of the steel used on the frame. Unfortunately, the welds were very poorly done. This is the one thing everyone has agreed on.

I speculate that the bottom flange cracked during the bending process (steel probably too brittle) which allowed moisture to penetrate causing the rust you see. With effectively no end caps to help support because of the bad weld, the bottom flange failed.

The dealer we purchased the motorhome from is sending the pictures I supplied to Thor to see if they will do anything. The unit is 2 years old and therefore out of warranty. We will see.

I do suggest anyone with a Thor motorhome on a Sprinter chassis that is towing inspect the frame where the hitch is attached before they take off.

[twinboat]

That crack didn't just happen when the hitch collapsed.

With all of the rust along the seam, its been cracked for a while.

Thete is no clean break in the picture.

It is a poor install. A bit support up the side of the frame would have locked it in.

Sent from my VS835 using iRV2 - RV Forum mobile app

[Hooligan]

Originally Posted by mnapier49

We were braking at the time as we were just exiting the freeway (very lucky), but I wouldn't say hard braking. Yes, the only welds involved are the end caps, however, my son (Structural Engineer) said that the end caps were critical to this particular design, especially considering the gauge of the steel used on the frame. Unfortunately, the welds were very poorly done. This is the one thing everyone has agreed on.

I speculate that the bottom flange cracked during the bending process (steel probably too brittle) which allowed moisture to penetrate causing the rust you see. With effectively no end caps to help support because of the bad weld, the bottom flange failed.

The dealer we purchased the motorhome from is sending the pictures I supplied to Thor to see if they will do anything. The unit is 2 years old and therefore out of warranty. We will see.

I do suggest anyone with a Thor motorhome on a Sprinter chassis that is towing inspect the frame where the hitch is attached before they take off.

I agree with your analysis. Hard to be precise but my frame bend (angle) seems to be more of a curve along the fracture area. I hope THOR does provide real support as this seems to be an unusual failure.

[hoosierrun]

I just had a Roadmaster base plate rip away (split) from my Toyota RAV 4. This was pulling up a steep incline in Lassen Volcanic National Park. It was nearly a disaster but nobody got hurt. I have a lot of property damage to the toad. Roadmaster is analyzing this for steel and design deficiencies. We towed 27,000 miles with this setup. Everything was inspected prior to leaving for vacation and was good. There was never a clue that something was wrong. We camped the night before and were on our way out in the morning. Too scary.... plus I found that the towing safety cables are attached to the base plate which means when it snaps off, toad could roll away. Fortunately we have a brake break-a-way switch. I hear people don't always install braking systems on their small toads. Here is an example of why you need one!!! I'm researching similar occurrences of this issue and came across your post. Anyone else ever had this happen?