Topic: delete

[CobraSpeed]

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[Bob Gaines]

I believe that they are a grade 5 even though they are not marked.

[Bob Gaines]

Do you happen to know of any references I could provide to AMK on this issue? I'm disturbed they are selling grade 2 bolts for the top loader tail housing and telling me that is correct.

I can almost guarantee the OE bolts I reused were not grade 2.

Not that I can think of at the moment however the fact that the bolt does not hold up under the specs that it is expected to be exposed to based on the application indicates that something is wrong. Would a grade five bolt hold up under similar torque without twisting ? Yes. FYI Grade 5 is a typically what you find at the local hardware store bolt bins too. Nothing special.

[suskeenwiske]

You can likely find reference material on-line that will give you some idea of the various Bolt Grades and their Torque Ratings. Grade 2 steel has a low carbon content; it's soft and will easily stretch and twist. These are the Bolts that commonly shear off at the head. Variables, like Bolt Size, Threads per Inch, Length, Lubrication, Temperature, etc., will determine the Maximum Torque that can be applied. In terms of the Bolt Sizes commonly used in Automotive applications, roughly speaking, puts the Torque Range around 15 - 25 ft/lbs. It's hard for me to believe that Grade 2 would be used or considered acceptable in any Torque Specific Application that may be considered Medium to Heavy Duty. Again, check on-line or visit a local fastener supplier, if there's one in you area, for Reference Materials.

On a different but somewhat related note, it's interesting to me that AMK should come up in this thread. I'm curious if anyone else has experienced issues with their products? Over the last year or so, I've purchased various AMK Fasteners that just don't seem to be of the same quality as they were 10 years ago. I've had some that just snapped in half with little force and even the appearance is different in some cases; almost as if they are knockoffs. I'm wondering if your experiencing this with your Tail Housing Bolts...though Grade 2 is still not Heavy Duty enough, in my opinion, to be used for your application.

All the best.

Ray

[Bob Gaines]

I haven't talked to Max for a year or two but have been friends for decades. He can be very stubborn (as with many of us  ). I do know that some of the bolts (not all)he is selling although the same specs as before have all together different makers markings then assemblyline which is a change from the past. He no doubt has had to go to different sources as supplies depleted. In the past he told me of huge 100,000 and more lots of a single type bolt he would have to buy to get the exact right bolt. I wonder that in that change (maybe smaller lots?) if he isn't getting some of his bolts that are made of the inferior Chinese metal that has been talked about all over the automotive industry as well as others?  That inferior metal may be one reason you have your problem.

[Bob Gaines]

In my sold opinion this is just plain dangerous and irresponsible on AMK Products part to be selling GRADE 2 bolts in their F-2874 (TRANS TAIL HOUSING - M/T) kit.

Quoted by Max at AMK "There is no way that the factory would have accepted grade 5 bolts without a grade marking or manufacturer ID. Bolts without grade markings should be presumed soft."

My understanding is Ford Motor Company had bolts such as the tail housing (in this case UNMARKED) produced by contract to their specifications and made on-site (Ford property) for quality control.

That would help explain the ability of other no name bolts found on Mustangs to function as Grade five. As Max said typically they would be marked as grade 5 with the 3 marks but if Ford was having them made to their specs that might explain why they are not marked but still offer the superior torque load.

[suskeenwiske]

In the generic world, Bolts are usually marked as shown in the diagram; I have no idea what Ford may have used at that time. Even then, you have to be cautious as imported fasteners today are frequently counterfeited; they may have the correct markings but are made of an inferior grade of steel.

One way to check visually but is not necessarily true in every case, is to look at the threads. Quality Bolts will have clean well defined threads whereas the threads on the cheaper type Bolts have a chipped appearance, missing metal, maybe some small holes and can be easily cut with a hack saw.

I'm fortunate to have a Mom and Pop Fastener Store within walking distance of my office that sells only US made quality guaranteed product and is where I now buy most of what I need. Unless I can find NOS or good used Originals, I will settle for non-original quality Bolts. I'm through buying reproduction...just too risky.

Ray

[jwc66k]

It would be difficult to determine the actual hardware without disassembling a transmission or getting a copy of Ford documentation but the service part number (sect 70.6 pg 1, 72 edition) is 20430-S8, 7/16-14X1 1/4in L, and is a grade 2 bolt. The same bolt is used from the transmission to the bell housing, and I've had no problem with original hardware being reused. 
Jim

[CharlesTurner]

I've had AMK lower crank pulley bolts shear off.  Thought maybe it was just a coincidence, but when it happened 3 times, hard to believe there is not a problem.  Not fun drilling broken bolts out of a harmonic balancer.

[JIMeast]

This came up on the VMF and 22GT checked the Ford Master Parts Catalog and was able to confirm the originals were listed as grade2.  He felt the torque specs might have been an error since it is shown as too high for a Grade 2 bolt.

[TLea]

A 7/16" grade 2 bolt shearing @ 40#? I find it hard to believe its a grade 2