Oliver | Luxury Fiberglass Travel Trailers, Campers & RVs › Forums › OLIVER CAMPERS › Ollie Modifications › changing bulldog coupler to 2-5/16"
- July 1, 2019 at 10:38 am #179127
Hi all…good morning.
Looking for input on changing the bulldog coupler to 2-5/16″.
The 2″ is rated for 7,000 lbs when installed welded. It would seem that installing with two bolts would decrease this rating by some. Even if it didn’t, the 7K lbs = Ollie GVWR. Is that really safe? Seems like it should come standard with the larger coupler to provide some safety margin.
Is the center tube 3″? I am looking at which coupler to get and they all seem to be for a 3″ mounting location. Looks like would have to remove the old one and use that as a template to drill the holes in the replacement?
Retire Navy Chief
ARS AB7RJuly 1, 2019 at 11:09 am #179169
You are correct.
Remove old hitch. Use tongue to take measurements from. Drill new hitch. Reinstall.
Steve, Tali and the dogs: Reacher, Lucy and Rocky plus our beloved Storm and Maggie (both waiting at the Rainbow Bridge) 2008 Legacy Elite I - Outlaw Oliver, HULL NUMBER: 0026 2014 Legacy Elite II - Outlaw Oliver, HULL NUMBER: 0050 2017 Silverado High Country 2500HD Diesel 4x4July 1, 2019 at 12:22 pm #179259
Anything rated for a weight should be fine at that weight. If I am within limits, then I feel fine. If they are following engineering best practices, it should have a safety factor (for automotive/ground transport usually around 3). Meaning it should be designed to support 3x the forces than those at the design load (7000lbs). Note these included dynamic forces (ie going over bumps/acceleration/decelleration) and not just static forces of sitting in your driveway. If it breaks and its loaded to less than 7000lbs, I’m not going to feel bad – it’s a defective part.
2019 LE2 #529 expected Sep/Oct 2019July 1, 2019 at 1:42 pm #179295
John E DaviesParticipant@john-e-davies
The issue with the 2” ball and coupler is not so much that you are maxed out, there is indeed a huge safety margin. For those with the Andersen hitch, the small ball wears very badly where the coupler is pushed hard forward by the tension on the chains. A larger ball provides more surface area and should resist that effect better.
Also, for larger trailers that is the most common size and some folks like to have a single ball that will work on multiple trailers.
Lots of good Andersen reading here…. https://olivertraveltrailers.com/topic/andersen-wd-hitch-faq/
"Mouse": 2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/
Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags.July 1, 2019 at 2:07 pm #179298
Thanks John….I didn’t even think about ball wear. But how does the 2″ ball with a 7K limit have a huge safety margin with a maxed out 7K lb trailer? Is the safety margin built into the rating of the coupler?
Either way….for the various reasons the larger ball just seems to make better sense, especially considering it’s only a $12 price difference between the two (Amazon prices).
ARS AB7RJuly 1, 2019 at 2:20 pm #179304
You can also get 2″ balls rated at 8000 lbs. Although you may need to replace your ball mount to accommodate the 1-1/4″ shank.
It’s the one I use. I don’t use the Anderson WD hitch, so can’t comment about John’s comment about decreased wear with a larger ball. Makes sense though.
2015 Oliver Elite, Hull 107
1998 Ford E-250, 5.4 literJuly 2, 2019 at 9:26 am #179442
As Dave pointed out, make sure you have the full rated 2″ ball with the 1 1/4″ shank. Don’t let the ball be the weak link.
I went to the 2 5/16″ coupler because I wanted more safety margin and because I already use 2 5/16″ couplers on some other trailers. I can use the same drawbar with a number of trailers. The real world difference between the two couplers is not much because of the way they are made and the way they are mounted to the Oliver tongue.
On mine, the mounting bolts had bottomed on the threads before they had fully pinched the coupler onto the tongue. This meant the bolts were in shear only and were beginning to elongate the mounting holes. The fix was simply to add some washers.
The excessive ball wear that John mentioned my be unavoidable because the coupler pocket is not a machined surface, but simply cast or forged to approximately round. The closing gate piece doesn’t make it exactly spherical either.
A small benefit is that the catch lever on the top of the 2″ mechanism goes away with the larger one. That thing always tripped me when stepping over the tongue.
"I only exaggerate enough to compensate for being taken with a grain of salt."
John 2019 Black Series HQ19
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