Slickrock 4X4 https://slickrock4x4.com America's #1 Off-Road Store Wed, 05 Oct 2022 17:38:42 +0000 en-US hourly 1 https://wordpress.org/?v=6.2.4 https://slickrock4x4.com/wp-content/images/cropped-jeep3_hill-2-32x32.png Slickrock 4X4 https://slickrock4x4.com 32 32 The first SUV, surprise, it wasn’t the Jeep? https://slickrock4x4.com/the-first-suv-surprise-it-wasnt-the-jeep/ Wed, 05 Oct 2022 15:22:37 +0000 https://slickrock4x4.com/?p=222765 The First SUV

Since the dawn of cars, the pickup truck has existed, the model T for instance was available in a truck model. Along comes WWII and American ingenuity invents the time honored tradition of the Jeep, the general purpose military vehicle that has won over the hearts of people all over the world. But… What happened when the pickup truck and Jeep decided to have a baby? The birth of the SUV!

SUV History Debunked

Now, let’s put a couple car history myths to rest. No, the Chevrolet/GM Suburban was not the first SUV. Yes, it is the longest running model line in all automobile history, but it was a panel truck, or, a truck converted to have a full length cab. Perhaps we can call it the first van, maybe a panel van. What about the Willys Jeep, was it the first SUV? Nope, it was a military general purpose vehicle with 4wd. Today, we consider Jeeps to be SUVs, but the Willys was much smaller than modern SUVs and was not designed for ‘sport’ but winning wars.

What is an SUV?

Ok, back to the original question, what was the first SUV in the modern sense of having truck-like capabilities, but plenty of interior room. What vehicle had both on and off road sensibilities? To answer this question, we need to look back to the golden era of the automobile, the 1950s.

The SUV Conception

The designer’s name was Ted Ornas of the International Harvester corporation. Ted was tasked with a difficult challenge. Design a vehicle with the sporty capabilities of the Jeep and give it the utility of the pickup truck. At the time, WWII was a decade behind and Korean war veterans were now returning home looking for a car that could be equally suited on city streets, as it was on a hunting trip or fetching supplies from the local hardware store.

Ted Ornas also wanted to ditch the tradition of slab side construction and bring in the modern curved sheet metal appeal so popular at the time. His initial conceptions, like the Jeep, were basic and utilitarian and lacked curves.

The SUV is Born

After numerous iterations, in 1959, Ted Ornas and the International Corporation created the first SUV, and they called it the IH Scout 80. The Scout 80 was nothing like any vehicle before it. It was bigger than a Jeep, could carry a small payload, was rated at ¼ ton but wasn’t the large footprint of a ½ ton pickup truck. It also had style elements, a rounded and pinched grille, radiused sides, seating for 4, and up to 10 if you asked IH. It also came with a full length metal roof if you wanted it. The roof could also be removed if you wanted an open air experience. The IH Scout 80 wasn’t a pickup truck, but it wasn’t a Jeep, it was an SUV, the very first SUV!

What else made the IH Scout 80 special? It had a ladder frame three times more stiff than the Jeep, a capable but plush leaf spring suspension, and was built farm tough with high nickel cast iron engine block that any farmer would find desirable. In fact, today, numerous IH Scout 80 SUVs drive around with original engines having never needed an overhaul due to the design choices made by International Harvester.

What did the Consumer Think?

The average consumer loved this new vehicle, it was at home in every situation the typical American would find oneself in. International Harvester sold more Scout 80s than their internal predictions indicated they would. Yet, other carmakers, such as Ford, looked at this vehicle as an oddity or fad that would not last. The consumer needed either a truck or a Jeep, why would they want something in the middle?

The Trend Continues

The IH Scout 80 was conceived in 1959, and production began in 1961. Production of the first SUV continued all the way until 1971. After International Harvester entered their 6th year of production. The Detroit automakers had finally taken notice. What they thought was a weird and irrelevant vehicle made by a farm and truck supplier, was a sales hit, and the Detroit automakers did not want to miss out on this new trend. Ford was the first to take action.

Ford Motor Company Copies the IH Scout 80

Everyone who owns a IH Scout 80 knows one phrase all too well, “Nice Bronco”! Well… it’s not a Bronco, but an IH Scout 80? Why do they say this? In Ford’s race to design an SUV to compete with the Scout 80, in 1966, they copied nearly every element of the Scout 80 to quickly bring their vehicle to market. Side by side, the nose, body lines, side contours, and interior layout nearly all mimic the IH Scout. Ford does receive credit for finishing touches and details but the two vehicles parked next to each other look strikingly identical.

How did it work out for Ford, very well. The Bronco is the classic SUV every American has a soft spot for. Fortunately for Ford, they had much better marketing and retail distribution creating unparalleled popularity for their Bronco line. The IH Scout 80 could only be purchased at a International Harvester dealership and these were farm equipment focused dealers often outside of cities selling to a rural crowd.

Ford Motor Companies city dealer networks helped them gain superior exposure and greater sales than International Harvester could ever obtain. We will hand the title of 2nd SUV to the Bronco, but the IH Scout was still first!

Detroit Automakers Follow Suit

When GM and Dodge noticed that both International Harvester and Ford had an SUV product, they both rushed a similar vehicle to market, but unlike IH and Ford, GM and Dodge wanted to minimize the design time and supply chain footprint. In doing so, both GM and Dodge took their ½ ton pickup truck line, shortened the bed, and put a fiberglass roof over the top. This is where the GM/Chevrolet Blazer and Dodge Ramcharger come from. Both good looking SUVs in their own right, but miniaturized versions of pickup trucks.

The Scout 80 Works Hard to Compete

With the introduction of the Bronco, International Harvester knew it would have to improve the Scout 80 to stay competitive. They released three late 60’s and early 70’s iterations to the Scout, namely, the Scout 800, Scout 800A, and Scout 800B. Each iteration introduces new enhancements, bigger engines, stouter axles, and better handling and safety features. In addition, International Harvester began releasing new trim packages aimed at generating continued sales of the original SUV. It was a good push, and in the end, 1971, International Harvester had sold over 100,000 Scout SUVs.

The Scout Morphs into Full-Size

International Harvester knew they needed to update their design to stay competitive. Starting in 1971, IH released the Scout II or Scout 2. Like GM and Dodge, IH chose to adapt their ½ ton truck chassis and sheet metal with a fiberglass top to create the latest iteration. The Scout II is known for being the most stout and bulletproof SUV of the 1970s. In their forward thinking, IH even released a Scout 2 with a diesel engine in 1980.

The End of an Era

Unfortunately, in 1980, International Harvester said goodbye to light truck production to focus on its heavy truck offerings. This resulted in the Scout SUV line being canceled never to be built again. Because the first SUV had a 19 year run and then faded into automotive obscurity, it is still an obscure vehicle mostly known by enthusiasts and SUV history buffs. This obscurity creates additional challenges for collectors and restorers because the part aftermarket is very small with almost no manufactures of reproduction parts being left.Still, many folks who lived during the 1960s and 1970s remember the IH Scout as the toughest and most reliable SUV available.

The Secret is Out

For years, the Scout 80 was a secret to the automotive community. Its original marketing in rural communities means that it was primarily owned by resourceful people willing to keep a machine running and used as a tool. This meant the Scout 80 was covered in layers of paint and parked outside under a tree when it reached the end of its useful life. This culture of ownership led the Scout to become the common persons project car. People were willing to share parts and information without the friction and budgets of collectors getting in the way. As time went on and more popular classic SUVs were collected and restored, people were looking for a new project and stumbled upon the Scout 80. Before 2015, it was common to pick up an old scout in decent condition for less than $1000. Times have changed and the Scout 80 now draws $5000+ for a project car! The Scout 80 has entered the realm of collectability, with excellent condition Scout 80s selling for more than $30,000.

The Legend Lives On

Next time you are at a car show or you see a Scout 80 on the road, remember, this vehicle is no ordinary classic car, but the car that reinvented what utility meant for America and started a whole new class of cars, the SUV.

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Is Your Dana 44 Vent Destroying Your Axle? https://slickrock4x4.com/dana-44-vent-axle/ Thu, 31 Oct 2019 04:45:29 +0000 https://slickrock4x4.com/?p=123188 Did you know that your axles breathe? Yes, axles breath every time they are used. As your ring and pinion spin round and round, they heat up the lubricating gear oil. Now, for those who may have forgotten high school chemistry class, when matter heats up, it changes volume. So as he gear oil expands, where does it go? If you have ever filled your own axle, you know that it is only ever filled part way. The remaining volume is left empty, one reason for this is to accommodate the expansion of the oil. As the oil expands, it needs to displace the air in the axle or the axle would become over pressured and blow gear oil out the seals in the axle tubes and pinion.

We know that the heat expansion wants to pressurize the air in the axle, so we can begin discussing how we prevent the pressurizing of the axle with the use of the vent. Every time the axle is used, air moves in and out through the axle vent. This air movement allows the system to heat and cool without us even knowing it. How many times do you think to yourself, “gee, my axle must be getting warm”. Most likely never. What is critical is that the only thing coming and going from your axles is air. This is where the Dana 44 vent breather system may or may not be helping. The Dana/Spicer corporation has put the breather vent on the axle in many locations over the years. Some of these locations are great, others not so great. So let’s get started on vent location.

The aft axle tube on the mid-plane as a small hole: 

This is probably the worst location the axle vent was ever located. In fact, some consider this the mythological vent location because it is actually pretty rare to find an axle vent in this location. You are probably going to find it on a housing pre-1970. First, the vent did not have a rattle valve on top of it, it is merely a 1/16 inch hole drilled into the tube. It is very susceptible to being clogged by mud and debris. What makes this vent hole even more troublesome is the fact that it is relatively low on the axle and if you plan on driving through any kind of mud or water, get ready for ingestion of mud and water by your axle. Folks with this version of the Dana 44 should definitely be draining and refilling their axle after any kind of liquid exposure because the gear oil can readily turn into a chocolate milkshake after wheeling. The contaminated gear oil will immediately begin to erode your ring and pinion, carrier bearings, and pinion bearings if left to its own self destructive behavior. If your axle really gets filled, the ingested water will begin corroding axle tubes from the inside out, as well as bearings. Once the corrosion and erosion starts, plan on a complete rebuild because it will destroy everything in the differential.

Dana 44 Axle Tube Vent
Dana 44 with Axle Tube Vent Near Spring Perch.

Upper axle tube: 

So this Dana 44 axle vent is very similar to the first one described but is in a different location. This vent hole is located on the top of the axle tube either as a blind hole or threaded to accept a breather valve. This vent is about 1.5 inches higher than the aft axle tube vent but is not substantially better if you have the drilled hole version without a breather valve of some type. What makes this vent location intriguing is that if it is located near the differential housing, it is located in the area of highest compressive bending stress in the axle tubes, maybe the engineer was at lunch the day they placed this one or just the cheapest to manufacture. The best version of this vent is often mated to the rear axle brake line T-fitting with either a rattle valve, or even better, a raised vent tube. This version is actually pretty common and found on a number of late model Jeeps with a OEM vent fastener for the brake block. If the vent is extended via a tube, its actually not that bad of a location, but there are better options. If you decide to truss your axle, it may be time to reconsider eliminating this vent because it is highly likely it gets blocked.

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The Dana 44 diff cover vent: 

When located on the upper area of the differential cover, this vent location can be an excellent option because it is located much higher than axle tube vents and usually can be easily modified for numerous different vent or valve types. It is also very protected being on the aft side of the axle. Things will get difficult when moving from one type of cover to another. You will need to make sure your new cover has the accommodation for the vent or you will have to modify it yourself. Finally, the biggest downside to this vent location is when it is in-line or near the oil sling path of the ring gear. If located in the oil sling path, expect oil to escape this vent every time you drive. If you notice oil escaping, you will need to keep close tabs on the oil level because the ring gear will keep slinging oil out until the differential is empty.

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Upper Diff Housing

Having the breather vent on the top of the Dana 44 is the best place to have it, especially when it is located on the offset flat above the pinion gear and pinion gear internal block flange (some Dana 44s). This will naturally keep oil from being slung out the vent while providing the highest possible location on the axle. It is also centered to the axle, which means that it will experience the least amount of tug when your suspension is flexing over obstacles. What makes this location a huge winner is that it is exposed to the least amount of collision potential with trail obstacles. Dana Spicer made this location the standard for the Dana 44 on quite a few versions. This vent also provides for unlimited options for valve and tube vent adapters. It is often the only vent location that allows for safe installation of the sealed volume accordion style vent breathers that can allow for axle air displacement while keeping all dirt and water out of the axle assembly. We believe this vent to be the most winning location of them all.

Dana 44 Upper Housing Vent Location
Dana 44 with upper housing vent outlet location.

So now that you have a little background about vent style and location, it’s time to consider what you want to do with your axle. The general recommendation is to convert your axle to the top differential housing style if you are currently running axle tube vents that are either the drilled hole or problematic. You may be using a differential cover vent and will be upgrading your cover to a vent-less design. What ever your reason may be, we prefer the upper housing vent location and will show you how easily this can be done.

Though it may sound spooky and difficult to make the conversion to an upper vent, it is actually a pretty easy modification for axles that do not have the vent installed in this location. So let’s get started with your vent modification.

If you have axle tube vents, the vent hole will need to be welded closed or permanently sealed with a sealant or epoxy plug. We recommend welding up the hole but if you do not have welder access, a well applied RTV can make due. Start by roughing up around the hole and then a quick plug weld and your done. After the weld is in place, clean it up with an angle grinder. If you install a new vent but do not plug the axle tube vent, it will be just as bad as never attempting the modification, do not skip this step.

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Once you have your old hole plugged, it’s time to place the pilot hole for the new vent. Before starting, you will need to round up the following tools.

  • Drill Bit (Size R or 11/32)
  • Drill
  • Center Punch
  • ⅛-27 pipe thread tap (NPT)
  • Tap holder
  • Tapping oil

The location is important but not overly critical. You will want to center punch a point about ½ to ¾ of an inch from the aft corner of the differential top flat, usually located to the right side of the differential housing. This will put the hole right over the pinon and the pinion oil block cast into the housing just where Dana/Spicer placed it on their factory axles. Next, with a well lubricated drill bit, drill right through the housing. The metal is about an inch thick, you will go through it quickly because the softer cast steel used in differential housings is quick to cut. It is best to do this with the differential cover off, you will need to clean up the shavings/swarf after you are done. If you are very careful and use a greased drill bit, you may be able to get away with not removing the cover.

After your hole is drilled and deburred, it’s time to start tapping the hole. Insert the ⅛-27 NPT tap into the tap holder and slowly start working the tap in and out of the hole. Use a liberal amount of oil or cutting fluid on the tap. As you insert the tap into the hole, ensure to maintain it perpendicular to the flat of the housing and only thread it in until heavy resistance is felt. Some resistance is natural but once the resistance feels like it may jam the tap, its best to reverse it out of the hole, clean out the cutting chips, and rethread the tap pushing ever further with each attempt. After a few cycles of tapping and cleaning, you will be all the way through and done with the tough part.

At this point, you will want to revisit steel shavings/swarf in the differential housing because the tapping process will generate more. You may also have a lip of steel on the edge that was pushed out during the drilling process. A debur tool can quickly remove this lip if its problematic, but a little lip won’t hurt anything.

Ok, now that we have the new vent hole tapped in our Dana 44, we need to decide on what type of vent to use.

Rattle valve directly 

This is an OEM style solution, this is where the rattle valve is directly threaded into the Dana 44 axle housing. If you plan on never getting in water, this solution may be good enough for you. The trouble is that even in the most desert of environments, there may be a stream crossing or water filled pot hole that needs to be crossed, making this the least preferred option.

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Rattle valve on the end of rubber hose 

This can be found on late model OEM style installs. The check valve is inserted into a rubber hose that is then connected to a tubing barb installed on the axle housing. The challenge of this style of axle venting is making sure you get the rubber hose and rattle valve higher than the highest point you think water will ever make it. Some run it up to the body undercarriage or a wheel well. Others will even run it to the engine bay and make sure the valve is higher than the engine intake. This is a great solution, just make sure you tie the hose and valve up in a secure way.

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Expansion Valve

 A newer solution is using an expanding volume valve. These are great because they allow axle air to escape into a sealed system that can then allow the air to return to the axle once the oil cools. Since it is sealed, you do not need to worry about dirt and water getting in, now long vent tubes to locate or tie up, and it is easily located on the axle housing in some cases. The sealed expansions do have some maintenance, you will need to inspect the expanding membrane to ensure it is not cracked or perforated.

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So you know a little more about how air escape works in you Dana 44. Hopefully this information keeps your axles full of oil without the intrusion of water or dirt. This guide is specific to the Dana 44 but is fully applicable to other vented axles, Dana 27 30 35 50 60 70 80 and others.

If you need help with your axle venting, please contact us at Slickrock4X4 and we would be happy to help you get the right solution for you.

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