May-29-2014 03:41 AM
Jun-02-2014 11:11 AM
Jun-02-2014 10:55 AM
Jun-02-2014 08:06 AM
Ron Gratz wrote:09KZMXT266 wrote:I'm guessing that the trailer only appeared to have a perfectly good frame when you dropped it off.
How do you explain I dropped the trailer off with a perfectly good frame, and I picked it up with a damaged one. I didn't tow it home with the plate, so the plate could not have caused it on my 7 mile drive home. To be fair I only saw the hole after installing the plate and tightening the chain nuts. Maybe I should have titled the thread did installing the Andersen damage my trailer frame?
It is quite possible that, in the 2000 miles of towing, the horizontal friction force caused by the plate rubbing against the bottom of the weld bead resulted in cumulative low-cycle high-stress fatigue damage between bead and frame metal.
Certain aluminum alloys are know to be susceptible to stress corrosion cracking.
The microscopic cracking might have gotten worse over the winter due to humidity and other factors.
When you got the trailer home, it is quite possible that installing the plate and tightening the chain nuts caused 1) the rear of the plate to push upward against the bottom of the weld bead, and 2) the rear of the plate to rotate to the right.
The right-directed friction force acting on the bottom of the bead could have caused the final failure of the already-weakened weld.
So, I think it is quite possible that the 2000 miles of towing with the plate rubbing against the bottom of the bead weakened the weld,
and the installation of the plate after returning from storage was the "final straw" which caused the bead to separate from the frame metal.
Ron
Jun-02-2014 06:16 AM
09KZMXT266 wrote:I'm guessing that the trailer only appeared to have a perfectly good frame when you dropped it off.
How do you explain I dropped the trailer off with a perfectly good frame, and I picked it up with a damaged one. I didn't tow it home with the plate, so the plate could not have caused it on my 7 mile drive home. To be fair I only saw the hole after installing the plate and tightening the chain nuts. Maybe I should have titled the thread did installing the Andersen damage my trailer frame?
Jun-01-2014 09:14 PM
Ron Gratz wrote:09KZMXT266 wrote:There's been much speculation about the cause of the damage -- so I'll add mine.
---Did the Andersen hitch plate somehow do it? Totally confused, and looking for your thoughts....
IMO, it is most likely that the Andersen plate is the cause of the damage.
We must keep in mind that the plate can move relative to the TT's tongue on all three rotational axes -- pitch, roll, and sway.
A key explanation was provided by Bryan (carringb) --
"They only rotate as one and even then, the urethane springs will allow a small amount of independent rotation until the springs provide enough force for the ball to breakaway and rotate within its friction cup.
"
The plate will also move fore-and-aft relative to the trailer frame as the vertical angle changes between the truck and trailer, such as when entering driveways with dips or going over speed bumps.
The OP's first photo clearly shows the top of the plate was rubbing against the underside of the broken weld bead.
The elongated shape of the worn area is proof that the plate can rotate in yaw just as Bryan explained in his first sentence above.
When the TV turns to the left, the plate will rotate counter-clockwise (viewed from above) relative to the tongue until the static friction between cone and ball spindle is overcome by changing chain forces due to compression and extension of the polyurethane bushings.
Another important thing happens when the TV turns --say, to the left. The relative yaw angle between TV and TT, causes the WD pitch-axis torque applied to the hitch head to exert a roll component of torque which causes the TV to roll to the right (CW when looking at the TV from the rear).
When the TV rolls to the right relative to the TT, the left side of the plate rises up relative to the left side of the front of the tongue.
Keep in mind, the OP stated, "My frame is 8". There may be 1/8" of clearance is all.
It wouldn't take much relative roll to close that 1/8" (or less) gap between plate and tongue.
So, we're in a left turn. The WD torque is attempting to roll the TV to the right, and the left side of the plate now is in contact with the bottom of the left weld bead trying to resist further rolling of the TV.
This provides the opportunity for the plate to exert a very large upward force against the bottom of the weld bead.
The friction torque between the Andersen's cone and spindle causes the rear of the plate to try to move to the right as the TV turns to the left.
Since the plate is being forced upward against the bottom end of the weld bead, there will be a friction force to the right in addition to the upward force on the weld bead.
The right-directed force on the bottom of the bead would tend to "unzip" the bead from the metal to which it was (perhaps poorly) attached.
The upward force on the bead would cause the buckling and cracking of the metal at the top of the bead, because the bead is much stiffer than metal above the bead.
I can see several reasons to believe the damage was caused by the hitch.
I see no reason to believe the damage was cause by a fork lift.
Just my thoughts --
Ron
Jun-01-2014 06:44 PM
09KZMXT266 wrote:There's been much speculation about the cause of the damage -- so I'll add mine.
---Did the Andersen hitch plate somehow do it? Totally confused, and looking for your thoughts....
They only rotate as one and even then, the urethane springs will allow a small amount of independent rotation until the springs provide enough force for the ball to breakaway and rotate within its friction cup.
The plate will also move fore-and-aft relative to the trailer frame as the vertical angle changes between the truck and trailer, such as when entering driveways with dips or going over speed bumps.
My frame is 8". There may be 1/8" of clearance is all.
Jun-01-2014 04:13 PM
BenK wrote:Ben it looks like you conclude that the chunks came from inside and were production scraps. I never thought of that but I felt something was'nt right with the weld also. This unfortunate mishap may have uncovered something that needs to be checked out. I wish this guy all the best.09KZMXT266 wrote:TecheMan wrote:
Looks like forklift damage to me. But here is the kicker. You say after hooking up last night you noticed chunks of aluminum on the ground. Why would they fall on the ground at your house and not on the road on the way home?
Because the road was flat and my driveway sloped toward the front of the street?
Looking at the pictures...they don't show any missing pieces or chuncks
So where did those chucks come from?
Betcha production scraps...not a good sign of ridiculousness on their
production process(s)
Jun-01-2014 03:45 PM
09KZMXT266 wrote:TecheMan wrote:
Looks like forklift damage to me. But here is the kicker. You say after hooking up last night you noticed chunks of aluminum on the ground. Why would they fall on the ground at your house and not on the road on the way home?
Because the road was flat and my driveway sloped toward the front of the street?
Jun-01-2014 07:15 AM
Jun-01-2014 05:22 AM
09KZMXT266 wrote:Then I really think it was a forklift with a ball on it. Hope you get figured out soon.TecheMan wrote:
Looks like forklift damage to me. But here is the kicker. You say after hooking up last night you noticed chunks of aluminum on the ground. Why would they fall on the ground at your house and not on the road on the way home?
Because the road was flat and my driveway sloped toward the front of the street?
Jun-01-2014 01:04 AM
jerem0621 wrote:
Ben, I think you are right on the money here. I question quicksilvers ability to weld aluminum after looking at this.
OP I would consider having an independent metal fab shop that works with aluminum inspect your welds. This incident could have exposed a problem with your trailer frame and potentially save you from an accident.
Please have those welds checked out.
With a metal frame you can usually see the failing welds because of rust. I'm not sure how to do this with aluminum.
Quicksilver or livin lite should be called as well.
Thanks!
Jeremiah
Jun-01-2014 01:00 AM
TecheMan wrote:
Looks like forklift damage to me. But here is the kicker. You say after hooking up last night you noticed chunks of aluminum on the ground. Why would they fall on the ground at your house and not on the road on the way home?
May-31-2014 06:09 PM
May-31-2014 05:36 PM
May-31-2014 11:46 AM