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- Newsgroups: misc.rural
- Path: sparky!uunet!charon.amdahl.com!netcomsv!netcom.com!geoff
- From: geoff@netcom.com (Geoffrey Leach)
- Subject: Re: Advice needed on farm/general use truck
- Message-ID: <1993Jan26.053142.16367@netcom.com>
- Organization: Netcom - Online Communication Services (408 241-9760 guest)
- References: <C180q6.2FI@mentor.cc.purdue.edu>
- Date: Tue, 26 Jan 1993 05:31:42 GMT
- Lines: 241
-
- lovejoy@cantor.math.purdue.edu (Victor W. Lovejoy) writes:
-
- >So our situation is: we need a truck (A Chevy) that can be used for driving
- >everyday and gets used like a car, and then has the capability to haul a
- >bed full of hay or maybe a few sacks of grain. We have looked at a 1500 that
- >had a bunch of options (used) and it seemed nice. The cruise/air/stereo/power
- >features would make my drive to Purdue easy to take, but will a Chevy 1500 be
- >strong enough to haul hay and feed? I've heard that in order to haul the 1/2
- >ton the truck is rated for, special coolers and suspension will be needed.
- >That seems crazy. If the truck will only haul 300 pounds in it's stock conditionwhy don't they call it a Chevy 300 pound truck?
-
- What follows is an edited version of several exchanges of email
- between myself and John Cooley (johnc@yuma.ACNS.ColoState.EDU)
- concerning the choice of a truck for towing heavy loads -- like tractors.
- I thought that it might be of interest in the current discussion,
- so I'm posting it, with John's permission. Responsibility for errors
- and omissions lies, of course, with myself. BTW, its possible to
- tell exactly what rear end a Ford has. There's a plate on the
- differential. Any Ford service department can translate the numbers
- there into specs.
-
- For what its worth, my conclusion was that the solution to my towing
- problem was Ford F-250 with a large V8 and C6 automatic transmission,
- with the Ford towing package, from the early 70's. I actually located
- a 1973 longbed with about 100K miles on it for $2500, but hte seller
- bugged out at the last moment. From what I can tell, it would have
- been a good choice. Your mileage may vary.
-
- In article <xvknacj.geoff@netcom.com> you write:
- >I need to get a full-size pickup with the capability of towing 5 tons.
- >What should I be looking for in terms of engine hp? Anything else in
- >addition to HD suspension and towing package?
- >
- >And while we are at it, anyone care to reccoment their favorite make/model?
- >The budget is $5000, which I think gets me in the early 80s.
-
- 5 tons... to me, that suggests 3/4 ton (Chevy 20, GMC 25 or 2500, Ford F250,
- Dodge 250) or 1 ton (Chevy 30, GMC 35 or 3500, Ford F350, Dodge 350). You
- should understand and be able to identify a full-floating rear axle. Most
- car salesman won't know anything about this, although many of them will try
- to fake it. 1/2 ton trucks never have full floaters, unless a previous owner
- has modified the truck.
-
- In terms of the engine, torque, especially between 1500 and 2500 rpm, is far
- more important than horsepower. For a 5 ton trailer, 350 lb-ft or more is
- desirable, which means you'll need a big block (454 in Chevy/GMC, 460 in Ford,
- 440 in Dodge).
-
- "HD suspension" may or may not mean anything. Salespeople and owners may
- claim "heavy duty" if it helps them sell the truck. "Heavy duty" relative to
- what? "Heavy duty" 1/2 ton trucks still will not stand up well under your
- proposed load. See if you can get the original window sticker and see
- exactly how the truck was equipped.
-
- With a trailer that heavy, most people will experience better reliability
- with an automatic than with a stick, although the auto should be the toughest
- available in a light truck. For Chevy/GMC of the years you are considering,
- a TurboHydraMatic 400 (THM 400) is the transmission of choice. I don't know
- the transmission spec for Ford or Dodge. Ford might be C6, if they were still
- being made. No one was making a very strong 4-speed auto in the mid-80s.
- You will be looking at 3-speeds. The transmission _MUST_ be equipped with a
- cooler for this kind of load. The cooler is visible behind the grill in front
- of the radiator. If there is no cooler, then the truck was not originally
- equipped for pulling heavy loads. Manual transmissions are strong, but
- require skillful use of the clutch with a big trailer. If the previous owner
- (or you) abused the clutch, it will need to be replaced. A manual transmission
- does not require a cooler.
-
- A 4.10 axle is standard for this type of application. An axle ratio of 3.73
- or less indicates a lighter duty truck. Fords and Dodges with diesel engines
- are exceptions, often having axle ratios around 3.50. The GM 6.2 liter diesel
- is not powerful enough for your application.
-
- The truck will suck gas and be fairly quick unloaded. The big V8 won't spin
- very fast, however, so with the short axle ratio, it won't have much top end.
- That's OK. Also, the short axle ratio causes higher engine speeds than a
- longer ratio. It's easier on the engine and drivetrain for heavy loads, but
- the engine will wear out sooner than it might in, say, a big station wagon with
- a 2.73 (that's right: 2.73 is common in cars) axle.
-
- Rear axles on light trucks come in two flavors: semi-floating and
- full floating. Automobiles, downsized sport-utilities, almost all full-sized
- sport-utilities and all 1/2-ton pickups come with semi-floating rear
- axles. Semi-floaters are nice and simple. Inside the axle housing (the
- outside part you see when you look under the truck) there is a shaft. The
- inside end (at the differential) "floats". It has splines which engage the
- output stub from the differential and a bearing that supports it.
- The outside end (at the wheel) does not float. It is firmly and directly
- attached to the brake drum and thus to the reast of the wheel and tire
- assembly. The outer end rides on one or two bearings between the shaft
- and the axle housing that support the shaft and the weight of the truck.
- The semi-floating axle shaft transmits torque and resists the shear imposed
- by supporting the truck. The outside end of the shaft is usually flat, and
- is nearly flush with the fact of the brake drum.
-
- Semi-floating axles also appear on 3/4-ton pickups with GVWRs up to 7,300
- lbs.
-
- The next increment of GVWR available will get you over 8,000 lbs, and this
- is where full floating axles appear. In a full floating axle, the shaft
- inside the axle housing only transmits torque. It has no role in supporting
- the truck. Splines on the wheel end, similar to those at the differential,
- engage the wheel assembly. The shaft pokes out to the wheel assembly through
- a hollow spindle. On the outside of the spindle is a much larger diameter set
- of bearings which supports the weight of the truck. This arrangement generally
- necessitates a substantial hub which sticks out through the center of the
- wheel. It is common, however, for some kind of hubcap or trim to cover the
- working hub.
-
- Full floating axles also appear on larger trucks, up to and including
- tractor-trailer rigs.
-
- This more complex arrangement makes brake work more expensive than on a
- semi-floating axle.
-
- On Chevrolet and GMC pickups since 1988, it's easy to tell if a truck has
- a semi-floating rear axle (GVWR 7,200 lbs or less) or a full-floating
- axle (8,600 lbs and up). Both 1500 and 2500 model pickups may have semi-
- floating axles, but GM trucks with semi-floating axles made since 1988 always
- have 6-bolt wheels. A model 2500 with 8-bolt wheels has a full-floating
- axle. A model 3500 (1 ton nominal, but actual payload as much as 3,500 lbs)
- always has a full-floating rear axle.
-
- Fords and GM trucks older than 1988 may have 8-bolt wheels with semi-floating
- axles. Look for the hub.
-
- Ford and GM both make their own axles. GM's are often distinguished by the
- number of bolts holding the differential cover on. Ford's are distinguished
- by an inch measurement taken somewhere in the center section, and I am not
- particularly familiar with them. The GM 10-bolt and 12-bolt axles are always
- semi-floaters. The GM 14-bolt is manufactured as both a semi-floating and
- full-floating axle. Dodge uses Dana axles. The Dana 44 is almost always a
- semi-floater; the Dana 60 and Dana 70 are full-floating axles.
-
- I suspect I implied that all pickup trucks with 8-bolt wheels have full-floating
- rear axles. This is not true. All trucks with full-floating rear axles have
- 8-bolt wheels, as far as I know, but some trucks with 8-bolt wheels have
- semi-floating rear axles. Clear as mud?
-
- The reason why the yard rental operator won't let you tow his tractor away
- may have more to do with your Toyota than the hitch that's on it. It sounds
- like you have a class III hitch, which, when installed on a sufficiently
- heavy vehicle, will handle 5,000 lbs without substantial risk of breaking.
- However, your Toyota is probably rated by the manufacturer to tow 3,500 lbs
- or less. Further, your Toyota weighs less than 3,500 lbs (assuming a 2WD
- pickup), and most of it is on the front wheels. Pulling a 1 ton to 1.5 ton
- tractor (2,000 to 3,000 lbs) on a trailer that probably weighs at least
- 1,500 lbs empty puts you at or over the manufacturer's limit for your truck,
- regardless of how strong your hitch is. This means that the owner of the
- rental place doesn't want you to sue him when your clutch dies. Further,
- if the trailer lacks a surge brake (a brake actuated by "pushing" backward
- on the hitch, like when you slow down), then it is very easy for the 3,500
- lb trailer to push the back end of your little truck around, especially on a
- curve, causing you to lose control of the whole works. The people at the
- rental place don't want to be sued for that, either. Your owner's manual
- probably specifies that you have brakes on any trailer over 1,500 lbs. A
- surge brake helps, but electric brakes with a control in your vehicle are
- the best solution.
-
- If you have a "heavy-duty" 1-ton Toyota (and Toyota applies these ratings
- differently than American manufacturers), it may actually be rated to pull
- 5,000 lbs (2.5 tons), but you can bet that Toyota requires brakes on a trailer
- that heavy.
-
- My Chevrolet Suburban weighs nearly 6,000 lbs empty, and has no special
- trailering equipment except for a Class IV drawbar hitch (7,000 lbs gross
- trailer weight, and 700 lbs tongue weight) and a transmission cooler. I have
- towed 6,000 lbs without difficulty, but if I were to tow that kind of weight
- cross country, I would want a trailer with brakes. The people at the rental
- places, however, are perfectly willing to let me drag a 2-ton tractor home,
- simply because my vehicle weighs enough to maintain control of the trailer.
-
- I suggested a configuration based on the idea that you might be towing
- something like a large triple axle "camping" trailer, boat or fifth wheel
- long distances. For occasional low-speed towing, you probably don't need
- something quite so strong, but you should also be aware that many small
- tractors and similar types of equipment weigh more than they look like they
- might. A medium-sized Bobcat loader weighs 6,000 lbs!
-
- How often do you rent this equipment? Where do you live? How far is it
- from the rental place and over what kinds of roads?
-
- This is relevant. Our mountain neighborhood has dirt and gravel roads with
- grades exceeding 15% in places. One fellow last year managed to get a
- Bobcat down to his house, but his pickup (American full size, 1/2 ton, 4WD,
- engine size and transmission unknown) wouldn't pull it back up again. He had
- to drive the pickup and empty trailer to the top of the hill and then walk
- down and drive the Bobcat up. He had no problem on paved roads, but on a
- steep dirt road, he needed more weight (for traction) and power than he had.
-
- I wish I had that much land! Actually, in the road-building business, 15%
- (15 foot rise in 100 feet) is _very_ steep. No year-round county road in
- Northern Colorado exceeds this figure. 30-40% is a maximum for an unladen
- 4x4, and may occasionally occur on a backcountry 4-wheel-drive road. When
- driving a road with a 15% grade, however, it seems much steeper. 30-40% is
- plenty steep enough for a blue ski run, although most skiers of such runs
- will insist that they are steeper.
-
- Highways are rarely greater than 7%. A 7% grade on a highway will be
- accompanied by warning signs for truckers.
-
- Nonetheless, 7% is plenty enough to put quite a burden on a small truck
- with a heavy trailer.
-
- It doesn't really sound like you need a big block engine, unless you like
- the idea of more power. I'd still recommend a heavy-duty 3/4 ton truck with
- full-floating 4.10 axles, heavy-duty automatic and towing package. This
- will handle the loads you're pulling and the grades you're dealing with, and
- will tolerate some abuse. It will cost more to run than the Toyota, and may
- have some quality control problems, compared to the Toyota. You should not,
- however, encounter any major failures in the engine or drivetrain, and a heavy
- trailer will be easier to control than with your Toyota. You might consider
- a beat-up used one, put a little money into rebuilding the important pieces,
- get minimal insurance, and only drive it when you need it. More hassle, but
- possibly more pleasant.
-
- A sway control device is essentially a shock absorber of sorts at the joint
- between the truck and the trailer. It reduces the tendency of the trailer to
- sway back and forth at speed. This is more important as the trailer gets
- heavier and the vehicle gets lighter. A heavy trailer swinging back and forth
- behind a light vehicle can kind of take control and cause the whole works to
- end up in the ditch.
-
- Patience. Good 3/4-ton trucks can be hard to find. They don't change much
- from year to year, so their owners tend to keep them, rather than trading
- for a new one.
-
- I hope this helps. It may take a while to find what you want, since many
- otherwise suitable trucks will be equipped with small-block (350-360 cubic inch)
- engines. This might be OK, or even preferable, if you can avoid hills and
- grades while pulling your trailer. American trucks are available in so many
- different configurations with so many options that many people find it very
- confusing to select one intelligently. Do your research carefully and
- understand what you're buying.
-
- People get a lot of work out of trucks with semi-floating axles, but for
- serious towing and hauling, I prefer a full-floater, and my next truck
- will have one.
-
- --
- Geoffrey Leach geoff@netcom.com
-