SouthernSon

Ran into an interesting little problem yesterday. Needed to replace all lug nuts on car trailer because owner before me used 12mm? instead of 1/2 X 20. However, although the 1/2's fit just right, the parts house had two different 'outside' width nuts (thicker). Since the plastic center hub depends upon the thicker lug nut to hold tight I have to exchange them for the thicker. Don't know if any of you guys have run into this before but I thought I might throw it out there.

SouthernSon

Oh, yeah, one of the nuts uses 3/4" socket. The other uses 13/16" socket. Dorman number 093 is the correct one (larger outside).

Han Solo

If you didn't replace the studs you better keep a close eye on them. 12mm is about .030" smaller than 1/2" so the studs are probably damaged. Trailer wheels are notorious for coming loose anyways. Especially the steel ones. I re torqued mine 15 or 20 times before they quit taking torque when it was new.

We had a guy come out with a 3rd gen RX7 and put his new wheels on with 1/2-20 lugs someone had sold him. He torqued them and everything but all 4 wheels came off 5 seconds into his run. It's one of those viral videos I had the misfortune of seeing up close and personal.

trackboss

ford version of the 1/2-20 are 13/16. The mopar version are 3/4.
As mentioned above, replace your studs. Trailer parts are cheap. You can save yourself some labor by just buying new drums/hubs with studs already installed. However, if you do that I would recommend replacing the races in them as well as the bearings with matched quality (USA, Germany, Japan, Korea) bearings sets.

rfn026

Here are the torque specs for trailer wheels. Keep in mind that you should check the torque at 50 mile, 150 miles and finally at 300 mile.

Richard Newton

k24556

I think i would get the studs replaced ASAP. It is one thing to get a disabled car off the highway in a safe place and another to get a trailer off the highway. the previous owner probably lost some lug nuts and did the emergency repair with spare car lug nuts. I'd do the same, worry all the way, but make it right when I got home.

My trailer has Dexter axles and the lug nuts hold the hub cap. They are 1/2 fine thread and take a 7/8 socket.

Also the Dexter Manual says the torque needs to be just a bit higher. See page 61:

http://united-trailers.com/Uploads/Manuals/Manual_6.pdf

Your axles may be a different brand, but the axle studs should be grade 8 and they may fatigue crack if you under-torque them.

SouthernSon

I appreciate the input. I do intend to check the studs and torque after a short trip. I imagine the previous lug nuts were, indeed, 12mm. Hopefully, the lug nuts are softer than the studs, or should be anyway.

SouthernSon

That torque sheet is way low! Dexter axles recommend 90-120 lbs.

NealB

looks low to me too

Discount Tire told me 125 for my 1/2" studs

Han Solo

Torque specs on that chart are not even close. 90 lbs minimum for 1/2".

Ford and Chrysler uses the 3/4" size on most of their older 1/2-20 car applications. GM and trailers usually use 13/16". My F150 has 13/16" lug nuts but I think the studs are actually 5/8". My 13 Mustang has 1/2-20 studs with 13/16" nuts also though.

rfn026

Thanks - I'll check that out.

Richard Newton

rfn026

I've changed the numbers. Sorry about the mistake, and thanks for pointing it out.

I'm alway surprised how different the torques numbers are from one manufacturer to another. That just shouldn't happen. Then again not a lot about trailers seems to follow conventional thought.

Richard

db2xpert

Featherlight specs are 130# for the Alcoa wheels

rfn026

I'm amazed at the difference between manufacturers. That just shouldn't be. Torque specs should be the same for a given size bolt. There's a difference between a dry torque spec and a figure for a lubed bolt - that should be it.

Keep in mind that a torque specification is just a handy way of measuring bolt stretch. A bolt is nothing more than a spring. When we tighten a bolt we're stretching this spring to hold 2 things together.

Richard Newton

trackboss

What makes it even worse is some (maybe all) assemble everything then paint. When I last did hubs/brakes on one of my trailers I had to remove all the caked on paint over the threads of the studs just to get the nuts on without doing damage. The level of craftsmanship in trailer parts is pretty low.

SouthernSon

Update: Lugnuts good and tight after 700 miles or so towing this past weekend. First check needed a turn of about 15 to 20 degrees after 100 miles, then everything okay.