[MattE]

I purchased a Reece hitch package for my 2014 Acadia SLT. The black bolts supplied Bed Bolt CL 10.9 M12 x 1.75 x 45mm will only thread a quarter inch. I have cleaned the threads of the weld nuts and done everything I can think of to seat these bolts but each only goes in a quarter of an inch. I then went to Fastenal and bought the same bolt but finer threads. Exact same problem. I have tried wrench, socket and even a air gun. Same problem over and over. Does anyone know the exact bolt that should be used for this. I am at a total loss at this point. Can anyone help?

 

[speleos]

Each manufacturer's hitch requires its own bolt length - the M12-1.75 spec should be correct. Hope the weld nut threads weren't damaged too badly by experimenting with fine vs coarse threaded bolts. Your best bet is to chase (clean) the threads in the weld nut with a tap for the original thread type and start over using bolts of the spec supplied with the hitch. If you need additional help, go to etrailer.com's website (or some other hitch installation site) and ask their technicians what you should do.

 

[GEORGEC]

If the bolts are turning in 1/4" then the pitch and diameter of the bolts must match the nuts. Do as Speleos suggests and get a tap to chase the threads.

Do not ever try to use a different pitch bolt/nut as you will damage the threads.

George

 

[Grantv]

Perhaps it Is the wrong threads.
M12 is just a hair under 1/2"
1.75mm pitch converts to .069"
1/2-13 has a thread pitch of .077"
It wouldn't surprise me if you could push / force that bolt in 1/4" with 12mm being a bit under 1/2" also.
Trying to force it is never a good solution. There's a very good chance you have ruined the threads. Have someone who knows their way around threads check it out, confirm what is correct. As said above, you might have to get the threads chased with a tap.

 

[Grantv]

P.S. it is also entirely possible, maybe more so, that there was something in there, and the threads were correct. Weld spatter for example.

 

[speleos]

P.S. it is also entirely possible, maybe more so, that there was something in there, and the threads were correct. Weld spatter for example.

The thread spec is correct according to this installation guide for a Curt hitch: https://images-na.ssl-images-amazon.com/images/I/71OAvyhnnfL.pdf
Source: CURT 13424 Class 3 Trailer Hitch

 

[mikethecpa]

I just installed a hitch on my Acura RDX and was having the same trouble. I sprayed weld nuts with lubricant and waited a day to try again. Then found round wire brush and put in drill and ran it up and down in weld nut to remove dirt. My Curt hitch came with 4 bolts and 2 nuts on a stick. In my case 2 of the bolts had coarse thread that fit the nuts on a stick and 2 bolts had fine threads that fit the weld nuts.

 

[NeilGraham]

Try using oil to help the bolts fit better.