Hmmwv a-arm bolts.

[LOWGEAR]

Any one know what size bolts are being used on the lower a-arms. I need longer ones for a winch install but don't know the diameter of the bolt.

 

[springer1981]

It's a 3/4" x 5" and you can get them in grade 8 at tractor supply for a reasonable price. I just did mine, check out my Avenger thread page 7 and it has some details on what to do. https://www.steelsoldiers.com/showthread.php?184818-My-new-1992-M998-Avenger/page7

 

[LOWGEAR]

Thankyou, I'll check out your Avenger page and stop by the Tractor supply on the way home today.

 

[springer1981]

On second thought they might have been 6" long. I remember debating on them and can't remember which size I went with.

 

[juanprado]

Go with longer as it makes it easier. If using a mile marker, then reverse the direction- Screw one in while pulling the old one out. Jack up to take weight off, makes it a breeze.

 

[springer1981]

No, go with the one that is the next size up from what is in there now. The shank will be too long if the bolt is too long. I really think the 5" is the correct one. I think a 4.5" would be better but was not offered in that length, the 5" left all the threads showing which is more than long enough. I also used the correct size washer and lock washer on install. Washer on the bolt before being inserted and lock washer on nut side.

 

[Milcommoguy]

Correct type of nut would be "top locks" Many of the bolts are not standard "off the shelf" hardware store stocked lengths. Always seems 1/2 inch to long or 1/2 inch to short.

Whatever works, grade 8, CAMO

 

[Retiredwarhorses]

There is no lock washer...I’ve installed many MM winch’s, you can use the old bolt and it works just fine.
the nut is a Stover top lock.
but it’s no problem to go with the correct 5in bolt

 

[springer1981]

The original nut doesn't need a lockwasher however the replacement bolt I used is a course thread and the original nut doesn't fit. I used a lockwasher and a course nut and it worked perfectly. If you use the course bolt a lockwasher would be a good choice.

 

[Retiredwarhorses]

The original nut doesn't need a lockwasher however the replacement bolt I used is a course thread and the original nut doesn't fit. I used a lockwasher and a course nut and it worked perfectly. If you use the course bolt a lockwasher would be a good choice.

If the original you had was not a stover top lock, you had the wrong nut, the bolts are 3/4in coarse thread.
Te entire truck uses no fasteners with lock washers for the most part...all are top lock.

 

[springer1981]

If the original you had was not a stover top lock, you had the wrong nut, the bolts are 3/4in coarse thread.
Te entire truck uses no fasteners with lock washers for the most part...all are top lock.

To be perfectly honest with you I didn't pay enough attention to the threads of the bolt and nut that I removed. Regardless, I replaced them, the washers and added a lock washer and used a regular nut. I'm certain it will be fine however I will check the original nut and if it matches the threads I will add it to the stack.

 

[porkysplace]

To be perfectly honest with you I didn't pay enough attention to the threads of the bolt and nut that I removed. Regardless, I replaced them, the washers and added a lock washer and used a regular nut. I'm certain it will be fine however I will check the original nut and if it matches the threads I will add it to the stack.

Lockwashers tend to break ,it's worth the small price of new locknuts.

 

[springer1981]

Lockwashers tend to break ,it's worth the small price of new locknuts.

We are talking about a 3/4" ID washer that is about 1/8" thick in Grade 8. It isn't going to break until long after I'm gone.

 

[porkysplace]

We are talking about a 3/4" ID washer that is about 1/8" thick in Grade 8. It isn't going to break until long after I'm gone.

On a A-arm that is getting beat to death going down the road ,even worst off-road . There was a reason the factory used locknuts , because lockwashers don't last,
Especially chinese lockwashers/

 

[springer1981]

On a A-arm that is getting beat to death going down the road ,even worst off-road . There was a reason the factory used locknuts , because lockwashers don't last,
Especially chinese lockwashers/

I appreciate your concern. As I have stated before, I am new to diesel's and new to HMMWV's but I am not new to mechanical work, 4X4', automotive and even some engineering. The lock washer isn't getting beat up by anything. The control arm and the movement of the control arm is buffered by its rubber bushing. The lock washer will not fail before the rubber bushing does. The rubber bushing in my truck is 27 years old and shows no sign of wear or age. Also the lock washer is firmly against the 1/4" thick winch mount that has zero movement in it. Before the lockwasher were ever an issue, the rubber bushing would have to break through a 3/4" grade 8 bolt.

If anyone would like to continue the discussion about the lockwasher, send me a pm and I'll give you my phone number.

 

[Retiredwarhorses]

I appreciate your concern. As I have stated before, I am new to diesel's and new to HMMWV's but I am not new to mechanical work, 4X4', automotive and even some engineering. The lock washer isn't getting beat up by anything. The control arm and the movement of the control arm is buffered by its rubber bushing. The lock washer will not fail before the rubber bushing does. The rubber bushing in my truck is 27 years old and shows no sign of wear or age. Also the lock washer is firmly against the 1/4" thick winch mount that has zero movement in it. Before the lockwasher were ever an issue, the rubber bushing would have to break through a 3/4" grade 8 bolt.

If anyone would like to continue the discussion about the lockwasher, send me a pm and I'll give you my phone number.

Its clear you will will do whatever you want, that’s your prerogative. But based on your statement about your skills, then you would know that high stress and vibration components don’t and won’t use split washers.
my suggestion is to use the TM 24p, it will show you every nut and bolt in the truck....