Generic Grade 8 Bolts???

[MarcSpaz]

Don't know where to post a car related question... but we have a lot of smart folks here that I think can answer a question I have....

So... I was doing some work on my Jeep and had a sway bar link disconnected. I buggered the threads while I was putting back on. So I could drive it right away, I went to the hardware store and bought a generic, anodized, grade 8 nut and bolt.

The bolt is a little longer than the original and the color doesn't match the rest of the bolts. It seems to be working fine, but the OCD in me knows its wrong and even though I can't see it, I want to change it. However, the bolt from the hardware store was $1 and the factory replacement from the dealer is $10.

Should I leave the generic bolt in there? Will it last for 50 years or is the weather going to rust it out in a few years? Should I buy the correct bolt because its "the correct bolt" or do I save my money?

[Snakester]

That Grade 8 bolt will last quite a while....May rust some and be hard to remove , but that is what Saws Alls are for ! I've got a buddy that has a 5 gallon bucket of SS bolts , nuts and washers. Let me know what size you need and at our next meet and greet I'll give you a handful !

[MarcSpaz]

Sounds good Randy! Thanks a bunch! I'll get the spec and let you know.

And the bolt is zinc plated, not anodized. Sorry for the mix-up.

[OakRidgeStars]

A generous amount of anti-seize or axle grease on the replacement bolt will help the next guy remove it when the time comes. The factory bolt is very likely galvanized, hence the gray color.

[MarcSpaz]

That's a good idea. I was going to paint it to help prevent surface rust, but the grease sounds like a smarter idea.

[trailrunner]

That's a good idea. I was going to paint it to help prevent surface rust, but the grease sounds like a smarter idea.

I think he was suggesting to put grease on the threads, not the bolt head.

[MarcSpaz]

I know. The bolt is not threaded all the way. The threads pass through a sleeved bushing, out the other end. The non-threaded part of the shank (called the grip) stays inside the sleeve. Though it is exposed on both ends, I was/am more worried about the part of the bolt with no threads (inside the sleeve/bushing) seizing to the inside of the sleeve.

The sleeve isn't supposed to move once the sway bar link is bolted in correctly. Instead, the rubber bushing twists and has spring like features used to help stabilize the vehicle by limiting body roll and side to side suspension ride height deviation. Since its not a moving part, I was thinking about pulling the bolt and painting the grip, but grease or anti-seize sounds like a better idea.

[dusterdude]

Marc,im fixin to do the same trick on my jeep

[Ironbear]

Zinc plating is a sacrificial anodic coating, so corrosion is unlikely to be a problem for a good while. Of course grease or paint isn't going to hurt it either.

[cwfunrider]

Marc,im fixin to do the same trick on my jeep

What trick? Are you referring to sway bar disconnects? Not sure that is what he was trying to accomplish. Sounds like he messed up the factory bolt.

Marc

The bolt you bought will likely be fine for some time. If it does seize some it can be pounded out. I have the JKS Quicker disconnects on my front sway bar. It uses galvanized pins. Galvanized is better than zinc but both are subject to corrosion.

Grease or even a good douse of silicone or wd40 will hold of corrosion better than paint. Paint chips and wears away.

Mobile Clicky Device

[MarcSpaz]

I put a 2.5 inch TeraFlex lift kit on my JKU Rubicon. I was supposed to replace the rear sway bar links and install factory rear links in the front. At first I didn't, but the front links were obviously short and it was noticeable in the ride. When I was pulling the driver's side off, I didn't realize that the front axle was as low as it was. When I unscrewed the bolt, the weight of the axle housing messed up the threads as the parts slipped apart.

I tried to clean up the bolt with a die, but there was too much damage and the bolt needed to be replaced. It was a stupid mistake. At least the Jeep was high enough that when the axle dropped, nothing hit the ground.

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[OakRidgeStars]

That's a good idea. I was going to paint it to help prevent surface rust, but the grease sounds like a smarter idea.

I think he was suggesting to put grease on the threads, not the bolt head.

That is correct.

[Ironbear]

Galvanized is better than zinc but both are subject to corrosion.

"Galvanized" is zinc plated. The question is whether it is hot-dipped (thicker) or electroplated. Bolts are typically not hot-dipped because it would fill in the threads. Zinc (along with Cadmium) is a sacrificial anodic coating*. The coating will corrode, electro-chemically protecting the metal underneath. Depending on the environment, this may take a long time, but when the zinc is gone the bolt should be replaced, as the galvanic protection is gone.

Stainless steel bolts are an interesting idea, but their relative positions on an anodic table suggest that steel around the bolt would galvanically corrode to protect the stainless! FWIW, there are Mechanical Engineers that make a career out of worrying about this kind of things. (I'm not one of them )

*If you are familiar with outboard or inboard/outboard boat engines; the zinc plating serves the same purpose as the little silverish fin normally down by the prop. It is usually zinc, and is there to "corrode" deliberately, providing galvanic corrosion protection to the rest of the engine. http://en.wikipedia.org/wiki/Galvanic_corrosion

[Snakester]

I bet next time you will be more CAREFUL with those THREADS !!!

[dusterdude]

Replacing the factory torx bolts with hex heads

[grumpyMSG]

I had 12 years as an equipment mechanic. It is always recommended to replace bolts with bolts that have similar properties. Do the research on what the correct grade is for that particular bolt. For a piece of suspension linkage that will directly affect the handling of your vehicle, is it worth it to be cheap? Grade 8 may be stronger in a given role, but it will break versus deform like a grade 5 will. Do not use stainless bolts to replace a grade 5 or 8 because they will deform even more quickly. I would recommend against using neversieze on the threads because it may encourage the threads to loosen, once it gets even slightly loose it will wear out any exposed threads and wallow out holes, before it breaks.

[MarcSpaz]

Lots of good information. I am very appreciative, to say the least. I'm learning a lot, which I hoped I would and why I posted the question here.

I have no idea what the grade of the original bolt is compared to a grade 8. I guess, the right think to do is just go get the factory original bolt and put it in there. They don't even stock them I'll have to order one.

Replacing the factory torx bolts with hex heads

Those torx bolts drive me crazy. It's like thay are trying to make you mad while you work on it. LOL

I bet next time you will be more CAREFUL with those THREADS !!!

Ain't that the truth. Hopefully I'll replace it this next time and that will be the last time.

[SHMIV]

I have to question the use of anti-sieze, myself. On the contrary, I might use LocTite on the threads; wouldn't want that bolt coming loose.

As to whether or not to put a factory-spec bolt back in place of the grade8... well, I probably would, simply because I don't know the difference between the two.

When it comes to parts that could cause accidents if they fail, I always err on the side of caution. I'd probably want to read some documentation that states that grade 8 is the same or better than the original bolt.

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[Palladin]

Grumpy is spot on about subbing stainless - don't do it. I had to use stainless in heavy electrical applications around themepark swimming pools, and they were nothing but trouble. If over torqued they will deform and wring before being able to loosen.

Busted bolts and washers falling around in equipment still makes me shudder.

[AlanM]

Google this: "galling of stainless steel fasteners".