BigToe
USA
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Joined: 08/01/2005
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The old hitch will not fit the new frame.
While the three bolt hole per rail pattern looks similar, the NBS frame rails are spaced a couple inches farther apart than the OBS rails , so the old hitch will have nothing to bolt to.
Ben, you're quite right. And I agree with your assessment.
IF that tube was indeed "cracked", and IF that crack propagated around the circumference of the tube, than it wouldn't matter if there were a thousand more side plates outboard of the business end of that tube.
But we don't know that it is a crack. You have estimated that it looks more like a cold lap. If the toe of the weld bead is higher than the tube, that might be the case. I have estimated that it might be undercut. If the tube is higher than valley of the line between the toe of the weld and the ramp of the bead, then that might be the case.
In either of those two cases, while not a perfect weld in appearance, one cannot conclude that the root of the weld did not penetrate the tubing. A year ago or more I posted details about the welding cell that makes this hitch. The penetration patterns that I've seen from hot and fast spray tranfers have a deep, elliptical root, with the long axis of this ellipse into the root.
So if this is a cold lap at the toe, or if it is undercut, it's not possible for me to assume that the materials are not joined at the root without destructive or high tech testing.
But even if I did assume that they did not fully join, there are two favorable aspects of the GM hitch design not found in other hitches. One, the fact that there is an additional side plate on that side, and two, the fact that the tube passes through, and is not just abutting, the side to which it supposedly did not fully joined.
A crack is different than a welding flaw.
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Juggler
Michigan
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Joined: 02/09/2001
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I'm not sure if I should be concerned about this or not. So I'll post a few pics here (since this is a GM receiver thread), and see what you think.
I am the original owner of this truck, so the damage shown has happened on my watch. TT generally weighs in the vicinity of 6,500lbs when traveling. I have a Reese WD hitch. I've visually examined the welds for cracks, and found none. However the hitch pin hole is elongated/elongating. Is this an indication of "soft" metal, or normal wear and tear? Thanks.
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Russ Chastain
Florida
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Joined: 08/23/2006
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Big Toe, thanks, I figured it couldn't be that easy.
Juggler, that's not normal wear. If I were you I would replace that hitch.
Today I looked over my 2001 factory reciever hitch. Spotted a crack and went ahead and pulled the hitch off the truck. Where the right side of the "U" piece joins the round tubing crossmember, the factory weld never penetrated the tubing. Rust between the tubing and the weld indicated that it was an old fault, and I think the weld was a very fast bead laid down without allowing the heat to melt/penetrate into the tubing.
I repaired that (ground and re-welded) and added some other welds where I felt it was needed, where the factory did't bother to weld 'em. When I ground back the faulty weld I went as far as I could with my grinder and never found the end of the fault... I believe there was no good "root" to that weld.
Just got in from priming and painting the hitch. I will put it back on the truck, even if I choose to replace it later - I will likely need to do some light towing this hunting season, and I'm sure it will stand up to that.
I did take pics, but they are still on the camera.
- Russ
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BenK
SF BayArea
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Joined: 04/18/2002
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Juggler, I've seen similar on traditional receivers, but of the ones I've seen
on the GM NBS were more severe, just like yours.
I think that the amount of flexing this NBS receiver has, exacerbates the working
of the pin hole.
Several very long discussions on these pins, whether to use them or a high grade
bolt.
I'm of the side of the fence using a looooong grade 8 bolt with grade 8 washers
on both sides of the bolt head and 1 hd nut & a lock nut on top of that.
Russ, if the OEM weld didn't penetrate, then if the 'other' side did, there
might have been movement with the 'other' side being the hinge. Thereby tin
canning the 'other' side's contact area with the cross tube. I think that is
the mechanisim of Scooter's failure (another thread here: How many are replacing GM OEM hitches?)
If there still is any portion of that crack, it's still a stress rasier and
will propagate itself again from there. Was that crack length wise along the
top flange of the "U" gusset or was it 90* to the length of the tubing?
I have Scooters pin box for pic's and analysis. Will have some more pic's soon
and think know the sequence of his failure 'at' the pin box to cross tube.
Also note that this type of issue or failure has micro fractures that are not
visiable to naked eye. Even microscope won't show them if they are covered by
a protective coating (paint). Mangaflux or X-Ray is the best non destructive way.
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Russ Chastain
Florida
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Joined: 08/23/2006
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>>Russ, if the OEM weld didn't penetrate, then if the 'other' side did, there
might have been movement with the 'other' side being the hinge. Thereby tin
canning the 'other' side's contact area with the cross tube. I think that is
the mechanisim of Scooter's failure (another thread here: How many are replacing GM OEM hitches?)
If there still is any portion of that crack, it's still a stress rasier and
will propagate itself again from there. Was that crack length wise along the
top flange of the "U" gusset or was it 90* to the length of the tubing?<<
I think the weld is now at least as strong as the material now, because I ran a continuous weld around the back side of the U-gusset as well as welding up the crack. I'll have to post the pics to Flickr and link to 'em from this thread.
Having said that, "at least as strong as the material" is not all that wonderful in the case of these hitches. The design ain't much, and apparently the material isn't the greatest.
- Russ
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JBarca
Dublin, Ohio, USA
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Joined: 12/16/2004
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Juggler wrote:I'm not sure if I should be concerned about this or not. So I'll post a few pics here (since this is a GM receiver thread), and see what you think.
I am the original owner of this truck, so the damage shown has happened on my watch. TT generally weighs in the vicinity of 6,500lbs when traveling. I have a Reese WD hitch. I've visually examined the welds for cracks, and found none. However the hitch pin hole is elongated/elongating. Is this an indication of "soft" metal, or normal wear and tear? Thanks.
Juggler,
Here are some things to think through if they pertain to you. See this post of mine where very similar wear in the pin hole occurred on my after market Putnam XDR in about 6 months time until I realized what was going on. Receiver pin hole wear Just I found it at the start of the problem, yours is more advanced. Could be a few years of it. How long have you towed with the TV?
While the GM reciever may have issues, this one I do not believe is due to the receiver design. The wear from the angle of your pic's looks to be in the bottom and rear center area. This is very similar to what can occur from using an angled pin where the pin's bend get's in the hole area and then you are not pulling on the complete OD of the pin.
So then the angled pin starts swedging the receiver hole as you tow and it can happen quick.
I disagree that this came from the weakness of the GM reciever. If the pin box was flexing up and down a lot, in WD mode the forces on the pin hole are UP. So then one would think the swedge would of occurred on the top. Yours is in the pulling direction.
I cannot see it harming the receiver at the point you are at now. But then again you did not state how much it is actually worn. If you are concerned see a hitch shop.
However, get your pin fixed to slow down the wear and if it really bothers you or get's worse, get a 3/8" thick plate, drill a clean hole in it and have it welded on the side. Caution on the hole. The hole is actually sized larger then the pin by some clearance. When in WD mode the shank pivots up and locks up in the pin box on the rear bottom of the pin box and the front top of the pin box. The pin is not under great upward stress as the reciever tube is taking the load. If you drill a size to size hole, then when WD mode is used the pin then may be under different loads than normal as the front top of the pin box has clearance to the top of the shank.
There has also been some folks who have heavy wear from jsut plain towing heavy. My TT weighs 6500# and you can see it started the pin box wear on mine from the angled pin. What TT weight is yours?
Hope this helps and let us know if you are using an angled pin or not.
John & Cindy
2005 Ford F350 Super Duty, 4x4; 6.8L V10 with 4.10
CC, SB, Lariat & FX4 package
21,000 GCWR, 11,000 GVWR
Ford Tow Command
1,700# Reese HP hitch & HP Dual Cam
2 1/2" Towbeast Receiver
2004 Sunline Solaris T310SR
(I wish we were camping!)
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BarneyS
S.E. Lower Michigan
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Joined: 10/16/2000
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Mine is worn somewhat also just like yours. I do not worry about it at this point. Perhaps someday I will have to do something about it but I just try to keep the pin from being pushed in so far that the "bend" is out a bit. This is not something exclusive to the GM hitch!
Barney
2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch
2002 Ford F250 Super Duty, 7.3L PSD
Visit our website here
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chadsalt
GA
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Joined: 04/04/2005
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this will solve the "enlongation" problem.
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TURK2500
SE Michigan
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Joined: 04/12/2005
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I installed a straight locking hitch pin link. My 7-pin connector is mounted close to my pin box, so this compact locking pin worked great.
Also keeps anyone from pulling the pin.
Turk2500
02 Chevy, 2500HD/4x4, 6.0L/4:10, GVWR 9,200lbs., GCWR 16,000lbs.
05 Jayco Eagle, 278FBS, GVWR 9,000lbs.
TV/TT loaded: 14,700lbs.
Loaded Tongue Weight: 1,200lbs.
Loaded TT weight: 8,400
Putnam XDR Class V, Reese HP Dual Cam.
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Juggler
Michigan
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Joined: 02/09/2001
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[quote=JBarca][quote=Juggler]I'm not sure if I should be concerned about this or not. So I'll post a few pics here (since this is a GM receiver thread), and see what you think.
I am the original owner of this truck, so the damage shown has happened on my watch. TT generally weighs in the vicinity of 6,500lbs when traveling. I have a Reese WD hitch. I've visually examined the welds for cracks, and found none. However the hitch pin hole is elongated/elongating. Is this an indication of "soft" metal, or normal wear and tear? Thanks.
Juggler,
Here are some things to think through if they pertain to you. See this post of mine where very similar wear in the pin hole occurred on my after market Putnam XDR in about 6 months time until I realized what was going on. [url=http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/16750965.cfm]Receiver pin hole wear[/url] Just I found it at the start of the problem, yours is more advanced. Could be a few years of it. How long have you towed with the TV?[/quote] [b]As I said, I'm the original owner of the truck. As far as towing, I've pulled this TT approx 25,000 miles, using this receiver.[/b]
[quote]While the GM reciever may have issues, this one I do not believe is due to the receiver design. The wear from the angle of your pic's looks to be in the bottom and rear center area. This is very similar to what can occur from using an angled pin where the pin's bend get's in the hole area and then you are not pulling on the complete OD of the pin.
So then the angled pin starts swedging the receiver hole as you tow and it can happen quick.[/quote][b]I'm not qualified to speak to the receiver design issues, however upon visual inspection, all the welds on mine appear good. The intent of my question was to acertain whether or not this "wear" was abnormal, in the experience of others.[/b]
[quote]I disagree that this came from the weakness of the GM reciever. If the pin box was flexing up and down a lot, in WD mode the forces on the pin hole are UP. So then one would think the swedge would of occurred on the top. Yours is in the pulling direction.[/quote] [b]Sounds reasonable.[/b]
[quote]I cannot see it harming the receiver at the point you are at now. But then again you did not state how much it is actually worn. If you are concerned see a hitch shop.[/quote][b]It's worn pretty bad.[/b]
[quote]However, get your pin fixed to slow down the wear and if it really bothers you or get's worse, get a 3/8" thick plate, drill a clean hole in it and have it welded on the side. Caution on the hole. The hole is actually sized larger then the pin by some clearance. When in WD mode the shank pivots up and locks up in the pin box on the rear bottom of the pin box and the front top of the pin box. The pin is not under great upward stress as the reciever tube is taking the load. If you drill a size to size hole, then when WD mode is used the pin then may be under different loads than normal as the front top of the pin box has clearance to the top of the shank.
There has also been some folks who have heavy wear from jsut plain towing heavy. My TT weighs 6500# and you can see it started the pin box wear on mine from the angled pin. What TT weight is yours?[/quote][b]My TT weighs approx 6,500lbs ready to travel. [/b]
[quote]Hope this helps and let us know if you are using an angled pin or not.[/quote][b]It does help, and I thank you and the other users responce. Oh and BTW, I do use the angled locking pin.[/b]
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