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Bolt Size

Discussion in 'Western Plows Discussion' started by cet, Nov 8, 2012.

  1. cet

    cet PlowSite Fanatic
    Messages: 7,196

    I am installing a ultramount on an 03 Chev 2500. Does anyone know what bolts I need to buy?
  2. Triple L

    Triple L PlowSite Fanatic
    from Canada
    Messages: 5,975

    I think they were mostly all 9/16 on the boss harness I just installed...
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Those are an easy one Chris. Your shopping list needs to include....

    (6) - 1/2" x 1 3/4" bolts
    (6) - 1/2" lock nuts
    (8) - 1/2" flat washers (hardened preferably)
    (2) - 5/8" x 2" bolts
    (2) - 5/8" lock nuts
    (4) - 5/8" flat washers (again, hardened preferably)

    If this is a used mount make sure you have the U-shaped backup brackets that slide inside the frame rails and that you use them. DO NOT install this mount without some type of backup bracket inside the frame.
  4. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    This depends on the mount of course. Sounds like you have the Classic GMC and the list that B&B gave you looks good. Western usually provides grade 4 bolts and nylock nuts but I recommend you get grade 8 bolts (hardened) and use as many flat washers as you can. Western doesn't send enough in my opinion. I have seen too many bolts rip right out of the frame because there were no washers. Put a flat washer on the nut side and the bolt side. Also, get "stover" nuts not nylocks. Stovers are metal interfearance nuts that thread on a bit and then the last thread "interfears" with the threads. Nylocks come loose easier than stovers especially if you use an impact to drive them on. With nylocks the friction of spinning on with an impact melts the nylon and they don't hold worth a shi*.
    Last edited: Nov 8, 2012
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Post up a pic of these grade 4's.
  6. cet

    cet PlowSite Fanatic
    Messages: 7,196

    Thanks :drinkup: It did come with the U brackets and I will use them. Wiring is all in, that was easy.
  7. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    I will take a pic of those grade 4 (maybe 3) bolt heads and post them along with the grade 8s we use. Will include a shot of the stover and nylock nuts too. I believe the lower grade bolts that come with have three tics on the head while the grade 8s have six tics. Will verify that and post some "evidence."
  8. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    No need. The point was there's no grade 4 bolts. :D
  9. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Details, details.... I am old and I don't remember the numbers sometimes. That's why they call me Al for short (short for Alzheimers) :dizzy:
  10. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    But details are important to your well being. Send him to the store asking for gr 4 bolts and he looks stupid. Guess who he's mad at now?
  11. cet

    cet PlowSite Fanatic
    Messages: 7,196

    I got it all mounted up yesterday. Pretty easy, I like working on the GM's.
    Everything works well but I still hate hand held controllers. Good job I'm not driving this truck or I would be buying a joystick.

    Thanks for the help.
  12. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    I thought all the 03 Light Duty GM trucks were GMT800. Did I miss a memo?

    How does an impact gun change the friction coeffiecent between the nylon insert and the bolt threads vs using hand tools?
  13. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Basic physics my friend. Friction X force applied = heat generated. More heat causes the nylon to melt away.

    Think about when you apply the brakes on your vehicle. When the vehicle is going slow (like a hand ratchet on a bolt) the rotors don't get hot. But when you are going very fast in your vehicle and you apply the brakes with the same force the rotors get hot. If you ever watch nascar at night you will see the brake rotors glowing red,

    You can pick this theory apart all you want and discard it if you please. I have never questioned it. My mentor taught me this precaution way back when I was an apprentice mechanic at a Dodge dealer in the late 70s. We had problems with wheel bearing preload nylock nuts coming loose. Chrysler determined that the problem was caused by impact installation. Take it or leave it.:nod: I am done with this thread, people like you make me not want to bother logging on.

    2core517 I see you had nothing to add to this thread except your critisism. Allow me to quote Bambi "if you aint got nothin nice to say then don't say nothin." We are all here trying to help out, some of us are actualy professionals who normally do this for money, but we donate our time and effort for free because we like to help. If you were starving and someone offered you food would you complain if it was cold?
    Last edited: Nov 11, 2012
  14. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    I'm just confused how turning the nut with a power tool causes more friction.

    Who says I'm not a professional?
  15. Andrew010

    Andrew010 Senior Member
    Messages: 204

    It's not so much about more friction as it is more heat from turning faster.

    If you can't understand how a impact would generate more heat than using a hand ratchet when installing a nylock fastener, you my friend should not call yourself a professional anything.
  16. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    The friction is the same, the BTUs generated are the same. Time is the critical component here. Sir mishnick missed that in his wanna be scientific equation. But he also suggested Grade 4 bolts that do not exist, and miss-spelled my username which indicates to me a lack of concern for details. Details are important, especially when someone proclaims themselves a "professional".
  17. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,990

    So much dis-information so little time:dizzy::dizzy::dizzy::dizzy:

    the lower the number the softer the bolt and the more apt to stretch higher numbers are harder and will shear before stretching. bolts are normally graded 2 (unmarked head) 5 (three "slashes) 8.8 (six slashes) there are other grades but these are the most common. Plow manufacturers use grade 5 and 8 and it is important that you use the right one in the right place. Use of a grade 8 when engineered for grade 5 could create a shear issue, inversely use of grade 5 when grade 8 is required could lead to stretching issues. The harder the bolt the more critical the proper tension, over tightening can create internal cracking leading to failure.

    Using a impact gun will not effect the ability of the nylock. It is important to mach the tool to the fastener, use of over-sized impact tools can easily over tighten bolts causing them to either stretch or snap (some fracture internally waiting to break under load.) Why they make impact tools (and torque wrenches) starting at 1/4 inch drive. Use of torque sticks can help alleviate this issue though they should not be used as a replacement for a torque wrench when a specific torque load is required.

    Impact tools should never be used to tighten bearings. Bearing are designed to operate under a specific amount of end play(pre-load) most often set in wheels by the torque load on the retaining nut and should always be tightened using a torque wrench.

    as an aside; Stainless steel fasteners are extremely susceptible to galling if too much heat is produced why you must ALWAYS use anti-seize or similar thread lubricant when using SS fasteners particularly when using power tools. This however leads to another issue which is over tightening and stretching/snapping the bolt. The solution; tighten to snug with an impact and finish tightening with a torque wrench.
  18. dfd9

    dfd9 PlowSite.com Addict
    Messages: 1,475

    Well, I was going to ask if this is the same mentor that taught you about Grade 4 bolts, but I see 2core1807548074 covered it already.

    Well, I s'pose.

    Andrew235094, did 2Core0187632487 make any reference to not understanding an impact generating more heat in less time. You did.

    Personally, I gave up on all this stuff, I prefer bailing wire and double nuts with lock washers on the bolt head and nut side. Grade 28 baling wire, that is.
  19. panhead9

    panhead9 Member
    from NY
    Messages: 31

    If you guys dont get how an impact can melt a nyloc try this put 2 3/4" bolt 4" long in your vice run one nyloc on all the way to bottoming by hand feel bolt TEMP now whack the other on with an impact feel bolt now tell me what you feel. its all right there the dude with the so called "SCIENTIFIC" explanation is correct