They should just make the whole 5th wheel assy out of aluminum! /ubbthreads/images/graemlins/wink.gif It would be nice and lightweight then....

Birken

 

This is known as a galvanic circuit.

To form a galvanic circuit, you need:

1) Two dissimilar metals
2) Physical or electrically-conductive contact between them
3) The presence of an electrolytic fluid, such as salt air or salt water.

Salt may not eat away at aluminum, but it will cause the aluminum to develop a white spotty oxide over time.

The greater the conductivity of and exposure to the electrolyte, the faster the galvanic corrosion occurs.

 

Where you are you do not see the effect salt/water has on aluminum. I've seen it, many times. An etching primer will do nothing to isolate the steel from the aluminum. The aluminum has to be physically separated from the steel by a non-conductive barrier or the aluminum WILL corrode where it contacts the steel. It is simple chemistry, nothing will stop it except isolation of the two metals at the contact points. Ask someone who has (or had) an aluminum hulled boat running in salt water that did not have the proper protection taken to isolate the hull from any carbon steel, or stainless steel, components. If they did not catch it in time they have a hull full of pinholes in the vicinity of steel components.

 

Thanks for the tips!

As of right now, the frame is painted black. Last owner did that.

I'll have to take a closer look at the 5th wheel hitch and mounting location. That'll be when it comes home and is warmer.

As I said, it will prob. live out it's days here on the farm. Just pulling a small trailer during harvest. If used during winter.... there isn't much snow nor ice on the roads. And if there is any, they don't use "salt" here any more. Suppose to use something "friendlier".

 

There's nothing wrong with aluminum truck frames. I've been working with them for years. Most problems start with loose fasteners that allow for increased movement and cracking to begin. Then someone that doesn't know anything about aluminum will try and weld it.I've stretched many short alum frame tractors into straight trucks for dump and farm use. I've seen these guys way overload them with wet silage or haylage. The alum frames hold up much better in the fields.The pitting you see in the photos' is electrolysis from direct contact with the 5th wheel frame. You can buy some etching primer that will prevent this from reoccurring. Surface prep will be the most important thing. Grade 5 bolts are NOT strong enough! Use grade 8 minimum or better yet use frame (HUCK) bolts. Make sure your bolts are cad plated to prevent them being frozen in the frame later. Kevin

 

It would depend on how much salt it sees, I guess if I was running it full time in the winter months in salt country I might pull pull the 5th wheel after a couple years just to see what the aluminum angle looks like. I'd still use the RTV between the alum angle and the steel. If it won't be used in the winter you can probably get away with just a good coating of RTV between the steel and alum. like the previous poster said. If the frame is severely corroded you might want to consider fishplating it with another piece of aluminum over the corroded area but then you are talking about drilling more holes in the frame in the area that is good to attach the fishplate so you again have to isolate the steel bolts/washers from the alum. I don't think you're supposed to weld on those frame rails. The secret is to keep the salt water from getting in between the steel and alum. If the frame is usable as is if you clean both the frame and 5th wheel brackets with a wire wheel real good then put a good layer of RTV between them so it seals the joint off good you should be ok esp. if it won't see salt. For the bolts you can gunk them with the RTV and also put it both under the steel washers and under the bolt heads and nuts so everything is sealed so water can't get in to an area that has steel to alum contact.

 

wrenchforfun,

What would you define as "periodically". Eventually, this old truck will end up as a farm truck (again). It prob will not get used during the winter months, only fall....

I'll have to take a closer look at eveything..... truck has yet to be brought home. Plus it's covered w/ snow....

 

I work for a large tanker operation, our trucks always gross out so weight is money. Early 80's the bean counters were specing aluminum frame rails, justified on weight savings. That was until the 5th wheel let go in a turn on one rig operating in the northeast causing a rollover. Root cause was the galvanic corrosion between the carbon steel brackets and the alum. caused by salt water getting between them. The bracket pulled right thru the frame at the area weakened by the corrosion. Alum is more reactive than steel causing it to corrode severely in the presence of steel and an electrolyte like salt and water. Bottom line is we replaced lots of frame rails, did it one side at a time, held everything up with jacks and after everything was detached from the rail pulled it out with a pickup, stuffed a new one back in. Contrary to what the bean counters said, it cost a pile of money, no more alum rails. One way around your problem might be to install an aluminum angle between the steel 5th wheel brackets and the frame. The alum angle will corrode where it is in contact with the steel bracket but the frame will be ok where it contacts the aluminum angle. You still have to isolate the steel bolts from the alum rails though, they make plastic sleeves for that. You will still have to replace the alum angle periodically because it will corrode also but that's better than the rail.

 

Silicone sealer.... man, it would have to be "painted" on thick. How about that tool grip dip stuff? Or paint on bedliner? As I said, the 5th wheel hitch is off currently, so eventually, I'd like to return her back into service.... so means I'll be putting it back on.

I was thinking of using grade 5 bolts, fine thread, lock nut with a flat washer on the inside and out. But, that would mean a steel washer sitting on the inside of the aluminum frame..... must think of way to isolate w/out it working loose....

 

What you are seeing is electrolisis cause by the installation of steel to aluminum without some kind of barrier. Paint will not do it. They make special materials to coat the frame between the steel and aluminum. I have found that silicone sealer works great. As for aluminum frames being good or bad, I have a 1964 Kenworth with the original aluminum frame rails. It was a log truck for the first 30 years of it's life. It has been a dump truck for the past 12 years. It works most every day too. The problem most people have with aluminum frames, is that the are designed with the flexing in mind. The cross members are located in certain places to allow for this. When someone changes the flex points by bolting something onto the frame in a location it was not designed for,(and usually improperly I might add) it changes the flex points and will usually cause the frame break. It happens to steel frames also, but they a a bit more forgiving with improper applications of iron bolted to them.

 

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they are so much lighter

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10 hole steel budd 24.5 = 90 pounds

10 hole aluminum budd 24.5 = 60 pounds

These are actual weights, that I got on the scale at the scrap yard.

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Are you saying a 1/3 of the weight isn't much? That's 30 lb's off a 90 lb wheel. That's 30x18=540 of un-sprung weight gone. That a lot.

Wayne B

 

.... by the way.... those pics..... they were on a truck on Ebay....

I'm the owner of that truck now..... it was cheap enough, I think. /ubbthreads/images/graemlins/shocked.gif /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/tongue.gif

 

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Re: piloted wheels.

My expierience with piloted wheels is very limited. Only our newest truck has them, and we have yet to use it enough to even have a aflat tire on it so I have never even taken one off the hub.

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So you know where I am coming from, I am a fire department mechanic with a small fleet ranging from the ancient to the somewhat modern

On the bigger trucks the Budd style wheels were sometimes breaking studs fairly commonly in the big city. I don't let this happen here because I yell at drivers if they drive like that. But take one look at the studs on these wheels and you will see what I mean. The studs themselves are about the size of the outside threads of an inner nut on a Budd wheel.

They use a 2-piece washer-nut. This, coupled with the hub piloting, prevents the wheel load from walking the nut loose as the wheel goes around, hence they are all right hand thread. You oil between the washer and nut, and the threads of the nut itself, but are not supposed to get oil between the washer and wheel. I use WD-40. They give much less trouble getting them busted loose the next time it seems.

And finally there are no more inner nuts. So to inspect the brakes on a 10 wheeler you only have to remove/install 120 nuts instead of 200 like on a Budd style and that is a big advantage in my book. Depending on the stud and its condition you may or may not be able to "single out" a wheel for a limp back to the barn; I have done it successfully.

Birken

 

A K-whopper is lighter than a Freight-shaker? Man, I'm having a hard time getting my head around that.

Re: Dumps (straight truck) splitting frames: I had 2 Brigadiers and a Mack DM -- all spec'd for dumps.

The Mack frame split several times, causing me a few weeks in downtime and thousands in repairs at "expert" shops. I ended up taking a whole day off and doing my own repair (drill, bolt with "grade 9" fasteners, weld patches) -- that lasted.

All 3 had steel frames; the GM frames seemed lighter than the Mack's -- which at first made me think "uh oh: they're more fragile." In the dump business, you don't get the luxury of babying your equipment: either it can do the job or it can't.

Anybody having experience as a fleet owner or manager will know that you can often get competent drivers that will care reasonably for the vehicle with which they are entrusted, but invariably and inevitably, grossly incompetent "drivers" get through the vetting process.

In that case, the best you can hope for is to have idiot-proof equipment. If it's got a manual transmission, you're begging for downtime and repairs related to shock loads (snapped driveline components) and abuse (fried clutches, etc.)

And if you've been dumping for a while, you know that a fried clutch only happens when the driver has stuck the truck in a remote area -- so you're looking at a tow charge on top of the repair costs.

Fortunately, I missed out on most (but unfortunately, not all) of that, but many of my competitors weren't so fortunate. Such is life, I guess. Anyway, my Mack had a 237 and I think a M6 trans; the GMs had 3208 Cat power with Allisons.

In heavy hauling & severe duty applications, nothing beats an automatic transmission, and the Cats I had were the envy of all the truckers at every job: the Allisons kept them in the sweet spot, and they would flat out MOVE when the go-pedal was mashed.

My Mack had a higher top speed and more power than the GMs, but round-trip times were usually almost identical between the 3 trucks (the GMs were quicker on short hauls, and vice-versa). I saw snapped axles from both Eaton and Rockwell, always behind a manual tranny -- and more fried clutches than I can count.

I mention all this to say that the shock loads transmitted to the frame are typically much more severe with a manual transmission; my guess is that the snapped frames others have witnessed also happened to trucks having manual transmissions.

Semis usually get comparatively smooth roads to travel over as contrasted against those for straight trucks; however, I can see where a tractor's frame would need to flex a bit.

On the other hand, I really can't imagine aluminum being weaker for a tractor application: the sales guy and the engineers should have ensured the frame was properly-spec'd -- and the frame of a properly-spec'd truck *should* last the life of the truck (or at least many millions of miles).

Aluminum isn't *inherently* a bad material for frames, and in some applications the tare savings can be worth very much more than the added cost.

If you've got frame cracking problems in a tractor, and you're using aluminum rails, switch to an automatic transmission. Do your homework and spec the right auto trans (and final drive), and you may actually see a significant improvement (reduction) in your fuel consumption. Regardless, I'm thinking that will cure your frame-snapping ills.

Other things to watch out for include incompetent loader operators and improper distribution of forces through the frame during especially loading (improper axle position, improper fifth wheel/kingpin location, etc.) -- not to make it too complicated, but the easy solution might not address your biggest problem (the *cause* of the frame snappage).

If I was hauling common freight with a semi, I'd want an aluminum frame in my tractor -- and probably in my trailer, too -- if I could get enough business to cube-out or if the savings in weight would help me get more loads (not over gross) or if the savings in weight would help me get to where I could get a better deal on fuel.

 

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Aluminum wheels made sense on the tractor because of the wieght savings. Its allows you more payload. Plus lighter wheels takes less HP to rotate them, so you actually get a plus there besides. Aluminum also has more rigidity than steel.
Its not all just about looks, they're functional. You do have cracked wheels on occasion but your going to have that with steel ones too. One differance and don't know why, steel seems to crack and keep going all the way around. Aluminum will teend to crack from a lug out to a hole and stop.

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I certainly understand the urge for light tare. If you want a light truck, you put 2/3rd's of an engine in it such as a cummins L10 or now the M11, and 8 speed transmission, a 40 gallon fuel tank and a light suspension. You add light rear ends, flimsy wheels, low profile tires and the truck weighs a lot less. OH yes, don't bother with a sub frame, just bolt your stuff right to the truck frame.

I think it is a matter of philosophy whether you get a 'flimsy 'R us' truck, or whether you go the otherway and get a Cat engine, a 18 speed and 44k rears with Hendrickson suspension and a double steel frame.

there are loggers on the road built both ways.

the light weight trucks haul more, but it is not all profit. they get to the junk yard quicker, and the light weight drive train makes them a bit slower on the hills.

Mostly this shows there is more than one way to build a truck.
Frankly, I am quite content with a fairly heavy truck.

 

Re: piloted wheels.

My expierience with piloted wheels is very limited. Only our newest truck has them, and we have yet to use it enough to even have a aflat tire on it so I have never even taken one off the hub.

I have wondered if they were a better mouse trap or just a different mouse trap. Our '96 binder 4900 has them (steel, of course)

the traditional castle and crown Budd wheel mount has had a long run.
One of the photos of a truck on my web site is from the late 1920's with 10 hole budd wheels on it.

do you think the piloted wheels are actually better????

 

As I recall the last set of drums I put on were somewhere like 120# or 130#, they were heavier than the vo-tech student I had putting them on. /ubbthreads/images/graemlins/wink.gif But he got them on nonetheless!

Birken

 

Aluminum wheels made sense on the tractor because of the wieght savings. Its allows you more payload. Plus lighter wheels takes less HP to rotate them, so you actually get a plus there besides. Aluminum also has more rigidity than steel.
Its not all just about looks, they're functional. You do have cracked wheels on occasion but your going to have that with steel ones too. One differance and don't know why, steel seems to crack and keep going all the way around. Aluminum will teend to crack from a lug out to a hole and stop.

 

Birken, always spec'd drums with minimum weight of 106#. Lot more braking and less cracking. Bought 25 new KW's with Centrifuge drums. What a joke. Ran at legal gross in areas with 7-8% grades, no jakes at that time.

 

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I have been looking for some bare aluminum frame rail from a truck to make some loading ramps for my lowbed.

Its harder to find than you would think. At least in all the places I have been looking. Anyone know where I can scare some up for less than the price of new ones? Preferably in CA,NV,or AZ.

I would like to get two ten foot lengths. The steel ones I have now get Very heavy after the tenth time you drag them to the back of the truck in the rain in one day.

After seeing several trucks with aluminum frames and big cracks you couldn't give me one for anything other than lowbed ramps. My buddy has pictures of us welding back up an aluminum frame rail under a ten wheeler dump that had completely split in two.

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I saw one sitting at the KW dealer but it was attached to a fairly new truck! Maybe they were trying to get rid of it, I don't know. My logger friend spotted it immediately, like I say he loves those things.

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oh and aluminum wheels on big living quarters horse trailers keep the tires well on the trailer. the heat buildup in a 16" tire under the stress of a big 6 horse with living quarters in pretty crazy. The aluminum wheel dissipates that heat before it lets the tire come apart.

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That's what I'm talking about.

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we got some companies runnin threw our shop here in ohio that run the super singles on aluminum rims. they are fuel tankers. if i remeber right with them tires on there, they can haul another 200 gallon or so. got the tires on the trailers too. also lighter brake drums, and they run KW after finding out they are the lightest. good old marathon fuels.

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That's funny because I spend time going through the Webb catalog finding the heaviest brake drums that fit my dimensions for fire trucks, they often come with the midrange ones which of course disintegrate from the abuse. I imagine these guys go with the lightest ones and have the drivers take it easy on the brakes....

Birken

 

we got some companies runnin threw our shop here in ohio that run the super singles on aluminum rims. they are fuel tankers. if i remeber right with them tires on there, they can haul another 200 gallon or so. got the tires on the trailers too. also lighter brake drums, and they run KW after finding out they are the lightest. good old marathon fuels.

 

I have been looking for some bare aluminum frame rail from a truck to make some loading ramps for my lowbed.

Its harder to find than you would think. At least in all the places I have been looking. Anyone know where I can scare some up for less than the price of new ones? Preferably in CA,NV,or AZ.

I would like to get two ten foot lengths. The steel ones I have now get Very heavy after the tenth time you drag them to the back of the truck in the rain in one day.

After seeing several trucks with aluminum frames and big cracks you couldn't give me one for anything other than lowbed ramps. My buddy has pictures of us welding back up an aluminum frame rail under a ten wheeler dump that had completely split in two.

oh and aluminum wheels on big living quarters horse trailers keep the tires well on the trailer. the heat buildup in a 16" tire under the stress of a big 6 horse with living quarters in pretty crazy. The aluminum wheel dissipates that heat before it lets the tire come apart.

 

When it's the difference between "can throw them into the back of the pickup" and "can't," it is a big difference to me. I am talking ease of working on them here, since wheels (should) be removed fairly often for inspection purposes at least.

Birken

 

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they are so much lighter

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10 hole steel budd 24.5 = 90 pounds

10 hole aluminum budd 24.5 = 60 pounds

These are actual weights, that I got on the scale at the scrap yard.

 

I know this logger who swears that aluminum frames are the best thing ever, he has a self loader, but he kind of marches to a different drummer. /ubbthreads/images/graemlins/confused.gif

As far as aluminum wheels go, well since the advent of the hub piloted, integral washer, right hand lug nut, it is at least harder to see working under a lug, especially if you put a chrome cover on it, but I must say I certainly prefer them for the old back, they are so much lighter. Also the ride is improved and tire and brake heat dissipation is better. In my book aluminum wheels are a money saver in the long run.

Birken