Suspension bolts

[isaac_alaska]

Charles is right, a ball hone is really only used for applying a desired surface finish, and is not suitable for removing any appreciable amount of material. We use them all the time on Nikasil engine cylinders as a "deglazing" tool. On a soft metal like these bushings I would expect them to load up right away and act more like a smearing tool than a reaming tool.

[Elwood]

In addition to the "smearing effect", the individual balls of a flex-hone might beat up the edges of the grease grooves.

Thanks for input on the flex-hone, guys. I've never used one, so have no experience with them, but thought they might be easier to set up on the end of a spring pack than a typical multiple-stone power hone such as I've used on cylinder bores.

[w30bob]

Great thread guys.........lots of good info. Not being a machinist (not sure I can even spell it properly) when Charles is talking about honing these bushings is he talking about using a large machine-shop hone and fixturing the leaf spring (with bushing installed in the eye) in the honing machine........or is he talking about using something like a Sunnen portable hone, which attaches to a drill or other electric motor (via a chuck) and fixturing the leaf spring in a big vise? Or is it neither? Sorry to be asking the stupid question......but I want to understand what this thread is trying to explain.

thanks,
bob

[just me]

I have a Sunnen Pin hone and an old reamer driver (that I don't use for this job) and racks of hones and adjustable reamers. I measure the pin, measure the bore then hand drive the reamer to fit. No different than King Pins on a beam axle. If you can do a satisfactory job on kingpins, suspension bushes should be a piece of pastry.

[Elwood]

While researching some more on the subject of fitting the bushings to the suspension pins (or any other application with soft metal bushings), I came across some old reamers that were specifically made by Morse and also by Cleveland (and probably others) for brass, bronze, aluminum or other soft metals. Apparently the angle of the flute cutting edges is different than reamers made for hard metals such as steel. Typically, they'll be stamped or engraved with "BRASS" or "Cleared for brass" on the shank.

Is any one familiar with these soft metal reamers, and if so, are the results on bronze really better than using a standard HSS (high speed steel) reamer made for steel? I've yet to see one of these old soft metal reamers made with carbide blades, so either they pre-date that technology, or there's no advantage to carbide over HSS when reaming soft metals, or I just haven't seen them yet.

I can't seem to find a current manufacturer that still offers these soft metal reamers, either fixed or adjustable or expanding. Any one know of such a source (preferably one that isn't made in some unknown overseas factory with questionable quality)?

[isaac_alaska]

Somewhat relevant (maybe): tools like taps usually have a different tooth profile for different materials, and for some reason brass and cast iron take the same cutting tools (such as taps or dies) while mild steel would call for a different tap.

[RMS]

if you don't have access to proper hones and reamers in the field. a round file and a steady hand can can get the reaming job done. then dress up the bushing with a dowel wrapped in emery cloth or fine sandpaper.


the right tools are however needed to modify a Fedalloy or grade 12 bolt into a spring pin

[Elwood]

if you don't have access to proper hones and reamers in the field. a round file and a steady hand can can get the reaming job done. then dress up the bushing with a dowel wrapped in emery cloth or fine sandpaper.


the right tools are however needed to modify a Fedalloy or grade 12 bolt into a spring pin

That's an interesting job. Your handiwork, RMS?

[RMS]

no. the old guy (po) converted every pin and bolt on the frame of the 265 truck to a grade 12 or equivalent. he was a millwright and expanded on the overbuilt theme of the m37. there's probably a grand worth of fasteners on the frame.

[MSeriesRebuild]

No way would I ever use grade 12 in this application. Another story of my years in the grading business; we attached the angles to mount a 5th wheel to a truck frame using grade 12 bolts once. At the time I thought it would work great, NOT. We installed everything, torqued the bolts to recommended specs and went home for the day. Next morning, we found every bolt had popped and were laying on the ground under the truck. Grade 12 is too hard, they will shatter and break when used in applications other than those they are designed for. One of life's lessons learned for me, many times I've thought how glad I was that they broke before we got on the road pulling a lowboy with a 50-ton load on it; God was looking out for my ignorance. We installed it again using grade 8 bolts, ran for years with no issues. Grade 12 bolts are for specific special applications, they don't like it when us humans take them out of their intended environment.

[RMS]

I was and still am on the fence about the use of a grad 12s on the m37............the stock pins are so soft and the ones I received were not drilled for castle nuts. I hesitantly used the self-locking nuts that came with them....... with the pin being soft and the nut being harder, rather than the nut locking it just cut new threads and the nut fell off in a couple km. luckily it was the fixed end that failed and not the shackle end. been running a gr12 for two years front drivers side fixed end of the leaf. no issues yet

when it comes to say the lower front fender bracket to frame bolts, what is the best choice? for me I found the gr 5s would slowly stretch over time and the bracket would get floppy.......I switched them out for some gr 8s then promptly wedged a 3inch maple between running board and fender....long story short: next service I noticed the frame had taken a bit of damage as the gr 8s tried pulling themselves through the frame. a bfh was needed to flatten the frame and the bowed triangle bracket of the lower front fender bracket. would it better to constantly replace butter bolts (gr2-5) or run something that will shear before it deforms the frame or bracket ?

[MSeriesRebuild]

I was and still am on the fence about the use of a grad 12s on the m37............the stock pins are so soft and the ones I received were not drilled for castle nuts. I hesitantly used the self-locking nuts that came with them....... with the pin being soft and the nut being harder, rather than the nut locking it just cut new threads and the nut fell off in a couple km. luckily it was the fixed end that failed and not the shackle end. been running a gr12 for two years front drivers side fixed end of the leaf. no issues yet

when it comes to say the lower front fender bracket to frame bolts, what is the best choice? for me I found the gr 5s would slowly stretch over time and the bracket would get floppy.......I switched them out for some gr 8s then promptly wedged a 3inch maple between running board and fender....long story short: next service I noticed the frame had taken a bit of damage as the gr 8s tried pulling themselves through the frame. a bfh was needed to flatten the frame and the bowed triangle bracket of the lower front fender bracket. would it better to constantly replace butter bolts (gr2-5) or run something that will shear before it deforms the frame or bracket ?

My guess is you have other issues going on besides pins. Suspension components that are worn, twisted out of alignment, frame stress, twisting, etc. will cause pins to wear crazy, break, and maybe a few other odd things. Truck could have also been stressed from overload at some point. I've seen them abused off the charts. M37's are not really overbuilt, some people just look at them and think anything they throw at it will be fine; but that is not true. If I were you, I'd check around for warped frame components, worn and twisted springs and attaching parts.

[Elwood]

I was and still am on the fence about the use of a grad 12s on the m37............the stock pins are so soft and the ones I received were not drilled for castle nuts. I hesitantly used the self-locking nuts that came with them....... with the pin being soft and the nut being harder, rather than the nut locking it just cut new threads and the nut fell off in a couple km. luckily it was the fixed end that failed and not the shackle end. been running a gr12 for two years front drivers side fixed end of the leaf. no issues yet.

RMS, was that an NOS pin that failed, or a reproduction, and if the latter, was it from one of the military parts vendors, or made up by a local machine shop? With the self-locking nut, it doesn't sound like an NOS pin. If it's a repro, perhaps it wasn't heat treated, or wasn't heat treated properly?

[RMS]

was it from one of the military parts vendors

it sure was. I got pins and bushes for the whole truck from vp they were packed in a blue mesh "finger puzzle" (no holes for cotter pin)came with self locking cap nuts.

with the pin installed there was maybe one thread protruding from the nut. two sets of rail crossings and ting ting ting. stopped the truck walked back down the road. found nut and it was so lose on the threads I had to install the nut backwards to be able to carried on....lock nut was harder than pin and it cut new threads......on a different job I used gr8s and self locking nuts when I replaced the drivers side front spring hanger. no issues, nuts still tight: gr8 with gr8.

M37's are not really overbuilt, some people just look at them and think anything they throw at it will be fine; but that is not true.

I dont know......... all my buddies I 4x4 with have replaced their civi rigs multiple times. Im still on my first M37 after 13 years

If I were you, I'd check around for warped frame components, worn and twisted springs and attaching parts.

I could have some of that going on but what I was asking is....... concerning appliances mounted to the frame such as the lower fender mount to frame and cab mount to frame bolts... ..is it better to run a soft bolt that will stretch upon impact or a bolt that will sheer when impacted ? I ask because when I installed gr8 bolts in those areas and had impact the result was damage to the frame and bracket.

[Elwood]

was it from one of the military parts vendors

it sure was. I got pins and bushes for the whole truck from vp they were packed in a blue mesh "finger puzzle" (no holes for cotter pin)came with self locking cap nuts.

with the pin installed there was maybe one thread protruding from the nut. two sets of rail crossings and ting ting ting. stopped the truck walked back down the road. found nut and it was so lose on the threads I had to install the nut backwards to be able to carried on....lock nut was harder than pin and it cut new threads......on a different job I used gr8s and self locking nuts when I replaced the drivers side front spring hanger. no issues, nuts still tight: gr8 with gr8.

Unfortunately, not the first time I've experienced and heard that others have experienced something similar with other parts.

If I were you, I'd check around for warped frame components, worn and twisted springs and attaching parts.

I could have some of that going on but what I was asking is....... concerning appliances mounted to the frame such as the lower fender mount to frame and cab mount to frame bolts... ..is it better to run a soft bolt that will stretch upon impact or a bolt that will sheer when impacted ? I ask because when I installed gr8 bolts in those areas and had impact the result was damage to the frame and bracket.

I'd rather replace bolts than repair frame damage.