Dog legs for square front

Mon Nov 29, 2004 5:41 pm

Does any one know what to use to replace the nut retainer on the side tab of the dog legs for a square front 63 Low boy. From all that i hear it must be a late 63 to have this front. I bought 2 pretty well beat up dog legs ( the price was right and I was glad to get them). Please don't think that I am complaining.
I am thinking of using a Tinnerman D7988-1420 if I can't get the origional. These are for 1/4 20 bolts. Any ideas???
The listings i find for the tinnerman are by the 1000. I hope to be able to get fewer, but will probably have to get 100 or so. If any one else has the same problem I will share. I hate to go for my lungs for 1 lousey nut
The nuts tack welded to the top for the headlight mount are gone too. You can see where metal fatigue set in at the tack welds. It is a very poor design. I think that i will be able to make up a 1/4in or 3/8 backing plate and tap that or braze a nut to it and get a solid mounting.. Something, heavey hanging from two pieces of thin sheet will vibrate and destroy everything as this has.

Mon Nov 29, 2004 6:12 pm

The first thought that comes to mind is using JB weld or Devcon to attach a standard nut to the back of the metal. There is also a tool that instals a blind nut similiar to the way a pop eivet isinstalled, but the largest it goes is 1/4 x 20. They are available at many larger hardware stores, or at Harbor Freight at ... umber=1210

Mon Nov 29, 2004 6:58 pm

Johyn I take it you are answering on the headlight mounting. The tab on the side has a large square hole.


Mon Nov 29, 2004 8:41 pm

The tinneman nuts that oyu are talking about are they the ones that are in a tin cage that locks into a square hole?

Ralph in KY.

Re: Dog legs for square front

Mon Nov 29, 2004 8:53 pm

beaconlight wrote:Does any one know what to use to replace the nut retainer on the side tab of the dog legs for a square front 63 Low boy.

These are for 1/4 20 bolts. Any ideas???.

Not sure exactly which ones you are refering to. Parts book shows some 5/16 cage nuts with the doglegs. In any case, McMaster-Carr has them. 1/4 inch ones are around $8 for a pack of 25, depends a little on exact size needed. 5/16 run more each but are packaged in 10 or 20 depending on the exact size.

beaconlight wrote:It is a very poor design.

I don't think they stood up too badly considering a 10 year design life.

Mon Nov 29, 2004 10:32 pm

I had forgotten aobut hose being caged nuts. My system would still work buy JB Welding a washer to the back and a nut to that (would only be noticeable if disassembled), but getting the right part would be better.

Mon Nov 29, 2004 10:42 pm

Well , well I can't even tell 5/16 from 1/4 inch. I'm getting older than I thought. My Tinnerman number is wrong then. 5/16-18 for that thickness metal would be D7937-5618. I'l try Mcmaster-Carr and thank you.


Mon Nov 29, 2004 11:21 pm

Thanks Jim Becker!!!! :lol: :lol: :lol:

I ordered from Mcmaster-carr They had them and in a 20 pack. With shipping and tax it will come to about 20 bucks for a pack. At this price I'll change out the one on the other side too.


Thu Dec 02, 2004 8:31 am

I got the cage nuts from McMaster and carr today. They are 5/16 18 which is NC. As you remember one dog leg had a cage nut and the other had none. Well the old one is a fine thread. I will retap the course thread or replace the nut with a 5/16 NF square nut if I can find one. No sense having different threads on each side of the lowboy. If I do, I'll only try to put the wrong one in and really screw things up.
Any one need the cage nuts for the square holes on the dog legs of a square front let me give me your address and I will send them to you. I had to buy a package of 20. If I use 2 and keep a spare thats 17 extra to keep around the shop

Thu Dec 02, 2004 9:38 am

That's odd, I would have expected the original to be coarse threaded. You don't see a lot of fine threaded square nuts. I've never been into those parts, just going by the Parts Catalog. Maybe the existing fine threaded nut was a replacement somebody came up with. Wouldn't be the first time the parts book was wrong either.

I'd probably use 2 new coarse threaded ones.

Thu Dec 02, 2004 10:15 am

I probably will. The offer still stands for any one that needs some.