J.I. Case Building on Quality 

All new Case International 1680 for 1986

The 1600 series CaseIH Axial-Flows were introduced in the fall of 1985 for 1986 production. While they did not offer any major changes, they offered a lot of refinements when compared to the 1400 series they replaced. The rock trap was changed to a 3-blade design for better performance in tough conditions. The feeder house reverser became standard equipment. The concaves had an extension mounted to them which increased concave area for better threshing capacity. The rotor cage around the separation area had dozens of holes added to increase separation capacity. The clean grain elevator size was increased. The unloading auger rotated 15 degrees further ahead when unloading so the operator could see the unloader from the cab without strain. The unloader system also used a pair of switches that automatically shut off the unloader swing hydraulics once the auger had reached the end of its travel(whether in or out). There was also an indicator light to let the operator know if the unloader was not sitting on its saddle. The rotary screen for the radiator/coolers was moved from the side of the combine to the back of the combine for easier transport(less likely to hit an obstruction while being hauled down the road). The engine air cleaner was moved to the top engine cover for better "breathing" in dusty conditions. The cab filter was moved to the RH side of the cab so the operator would not have to take a "dust bath" when he shut the cab door from the outside. 6 large lights mounted on the top of the cab offered much better lighting in nighttime operation. The reel on a grain header could be moved fore & aft by the operator from the seat of the cab as well. The optional shaft speed monitor was now installed in the overhead console. The 1680 had an inclined delivery auger to fill the grain tank (this was optional on the 1660 as well). The straw chopper had a slow speed for conditions that did not require chopping of the straw. Perhaps what grabbed the most attention of the new 1600 series was the introduction of the Specialty Rotor. This rotor was a derivative of the old IH rice rotor, with short raspbar segments mounted in a spiral pattern throughout the length of the rotor. This rotor was offered for tough, green conditions where it offered much greater performance than the standard corn/grain rotor. The 3 larger models of "regular Axial-Flows" received some HP upgrades. The 1680 HP was increased to 225 by the addition of an intercooler to the IH DT-466( or referred to an a "Navistar" engine by CaseIH now). The 1660 added 10 HP by using a DT-466 engine. The 1640 used a D-466 engine at 150 HP. The 1620 remained unchanged at 124HP.

 1986 Case International 1620

Also introduced for 1986 were the 1000 series cornheads, 1010 rigid headers, 1020 flex headers, and 1015 pickup headers. The 1000 series cornheads were available from the model 1043(4RN) to the model 1084(8RW). 1010 & 1020 headers were available in sizes up to 30', and were available with hydraulic reel fore & aft. The 1020 could also be ordered with a 1 1/2" section sickle. This allowed better performance in tough cutting conditions. 

1660 with a new 6 row 1063 corn head

In 1987, the direction of rotation for the rotary screen was reversed. CaseIH had problems with buildup of chaff under the spinning screen, causing it to quit spinning in certain conditions. By reversing the direction of rotation, there was no "ledge" for the material to build  upon, allowing the rotary screen to spin freely. The shaft speed monitor became standard equipment in 1987 as well, since most machines had been ordered with them in previous years. Also, the final drive output shaft was changed to a one-piece forged shaft, instead of the 3-bolt and 1-bolt designs used previously. This offered greater strength and reliability. Also, the 1682 was introduced as the new model of pull-type Axial-Flow, replacing the 1482. The Power Guide Axle (rear wheel assist) axle was changed from a Mud Hog-sourced unit to a unit that was built with parts from Case's Poclain factory.

Case International 1682 Pull Type Combine

In 1988, the model number decals were moved up to the front of the combine beside the grain tank, instead of being mounted on the rear sheet metal on earlier models. Also, a new design was used on the rotor drive pulley. Previously, the rotor drive pulley was splined to the separator drive shaft by a narrow set of splines. The splines would wear out, causing the the rotor drive to quit turning. The new design consisted of a hub that bolted to the pulley and used a much larger spline area of the hub and separator drive jackshaft for much better life. Also, the concave hanger brackets on the RH side had the bolt holes in them slotted, which allowed the concaves to move sideways in relationship to the rotor. This resulted in the concaves being able to be moved for different conditions. In wheat, the concaves could have the point at which the rotor contacted the concaves (commonly referred to as the "pinch point") adjusted for varying conditions. This allowed a bigger "wedge" for the rotor to force the grain against the concaves for better threshing performance in hard-thrash conditions. This also allowed the concaves to distribute the threshed grain more evenly across the auger bed, allowing an even amount of grain delivered across the width of the cleaning system.

JP Farm's of Lynn Center, IL 1640 in oats

In early 1989, the Axial-Flows received very few changes. A "grain tank full" indicator was offered which let the operator know that his grain tank was full by means of a light on the steering column, among other things. However, a major change to the Axial-Flow line was instituted on April 1, 1989. Case replaced the Navistar engine line in the combines with Case/CDC engines. When this change was made, CaseIH also went to using small decal numbers on the rear sides of the combine. The 1660 & 1680 used an 8.3 Liter engine, while the 1640 & 1620 used a 5.9 Liter engine. Case called these combines XPE models, meaning Xtra Power & Economy. These new engines also gave their respective combine models more power. The 1680 now had 235 engine HP with a turbocharged, intercooled 8.3 Liter engine running at 2500 RPM rated load. The 1660 had 190 HP with a turbocharged 8.3Liter engine. The 1640 had 160 HP with a turbocharged, intercooled 5.9Liter engine. The 1620 had a 145HP turbocharged 5.9Liter engine. Also at this time, Case introduced heavy-duty cleaning system drive arms at this time for better reliability and in preparation for the introduction of the Long-Seive cleaning system. Also, dual wheels became an option.

Case International 1670s 

In 1990, the 1680 was introduced with the Long Seive Cleaning system. The seives were 13.5" longer which resulted in 792 sq. in. more cleaning system area. Also introduced was the "Operator Presence System", which would not engage the feeder unless the operator was seated and would shut down the feeder in 5 seconds if the operator got out of his seat. Also, a change was made in the hydraulic valve stack which eliminated the feeder raising by itself when the steering wheel was turned-a problem that had plagued Axial-Flows since electric-over-hydraulic controls were introduced in 1981. Also, the 1680 got a bigger hydraulic reservoir (8 gallons vs.5 gal. used previously) and used externally-mounted hydraulic filters, replacing the cartridge filter located inside the reservoir. Also, there was a change made in transmission/final drive ratios in an effort to improve braking that also included a 4th brake disc in the brake housings.

Case International 1680

1991 production Axial-Flows had a noticeable change. The words "Axial-Flow" were at the top of the cab, replacing the "CaseIH" emblem between the cab lights. Actually this served another purpose besides decoration. The area underneath it was redesigned so as to discourage birds from building nests in the windshield wiper motor area, a common complaint on earlier 1600 series Axial-Flows. The belt which ran the hydraulic pump was changed to a double V-groove belt for better reliability. The 1660 also received the different hydraulic reservoir/filter setup that the 1680 had received the year before. The unloader auger drive was changed from an open set of gears to an fully-enclosed, oil bath gearcase. More operators were "unloading on the go" and the open-gear unloader drive was experiencing more problems, especially in high-moisture corn. Also, the augers were spline-driven to and from the upper gearbox, instead of being fastened to the gearbox on previous models. The 1680 had 2 "elephant ears" removed from its rotor impeller, using just 2 instead of 4, for greater capacity in tough-feeding crops. CaseIH had also experienced engine failures on earlier Cummins engines used in the Axial-Flows. The original piston design did not have a "nickel-insert" around the #2 piston ring, causing the ring land area to break, causing major engine damage. CaseIH instituted a upgrade program to replace all the sleeves and pistons on affected units, replacing the pistons with a new, improved design that had a "nickel-insert" around the #2 ring land. CDC/Cummins also came out with various engine changes that allowed better oil temperature regulation and better filtration, which resulted in a new-design engine oil filter which bypassed a portion of the oil through a "super fine" portion of the oil filter. Also in 1991, production of 3 models of Axial-Flows ceased. The 1620 self-propelled, 1670 hillside self-propelled, and 1682 pull-type combines were discontinued due to declining sales numbers; leaving just the 1640, 1660, and 1680 self-propelled models to "carry on" the Axial-Flow banner.

1680 Axial-Flow unloading on the go

1992 marked other changes to the Axial-Flow line. The hydraulic system was changed considerably. A larger hydraulic pump for header lift was used, allowing faster raise speeds. The reel drive pump was "piggy-backed" to the header lift pump up by the engine. The LH side of the feeder house was a much cleaner design, leaving just the hoses for header hookup on the side of the feeder, eliminating a pump, belt, shields, and several hoses. The hydraulic valve stack was changed from a vertical design to a horizontal design, and allowed adjustment of raise and lower speeds. A new option available was Field Tracker, which allowed the header to tilt sideways independently from the combine. The was accomplished by using a moveable feeder adapter and sensors on the ends and middle of the header to determine the position of the feeder adapter for best results. The shaker arms & bushings were beefed up considerably, as the Long Sieve models were having problems with shaker arm/bushing life. In the 6 years of production, the 1600 series had underwent a large amount of changes-engines, sieves, hydraulics, etc. While the "base machine" was sound, it was time for some improvements. CaseIH would meet this challenge with a new series of combines, the 44/66/88 series.

1993 Case International 1666

In 1993, CaseIH introduced the 1644/1666/1688 models of Axial-Flow combines. On the outside they did not look much different from their predecessors, however, there were many changes inside. First, the Cross-Flow fan was introduced. It offered a more consistent volume of air to the sieves than the paddle-style fan that was used previously. The 44 & 66 models also received the Long Cleaning system for more capacity. An extra vane between the concave & grate areas eliminated a "dead spot" in the rotor cage between these 2 areas. The 1688 received a heavier separator drive belt and a heavier separator clutch assembly. Previously, the clutch was made of "steel discs" and "fiber plates". The new design used a "steel side" and "fiber side" on each disc and plate, allowing for more separator clutch capacity. The most noticeable change, however, was the reduction of engine RPMs on the 1666 & 88 models as the rated speed of the 8.3Liter engine was dropped from 2500RPMs down to 2200RPMs. This was accomplished by using different gearing in the PTO gearbox behind the engine as well as using a hydrostatic pump of higher volume to allow the same transmission speeds as slower engine RPMs. The engine horsepower increased as well on the new models as the 1688 used a 260HP, 8.3L turbocharged, intercooled engine. The 1666 used a 215 HP, 8.3L turbocharged engine. The 1644 used a 5.9Liter turbocharged, intercooled engine rated at 180Hp. The rated engine speed for a 1644 was still 2500RPMs. The 1010/1020 headers were improved in that the reel motor was moved to the RH side of the header, for better overall weight balance of the header. Also, the 1000 series cornheads began to use a "water pump-style bearing" on the front of the stalk rolls, replacing a bushing setup that required frequent greasing on previous models.

1994 Case International 1688

In 1994 a few changes were made. The 1644 chassis/frame, final drives, brakes, etc. were changed to that used by the 1666 for more commonality of parts. CaseIH also introduced what they called a "factory chaff spreader". The spreader discs were "dropped down" several inches and many components in the discharge area of the combine were changed so that all of the discharge material (straw and chaff) was fed to the now-solid spreader discs for better spreading of all material, eliminating the need for an "add-on" chaff spreader which had become necessary on most combines for acceptable spreading of chaff. By 1994, CaseIH had realized that some more drastic improvements were needed for the Axial-Flow line. This next challenge would be answered by a redesigned series of combine-the 2100 series.

The 1688 the last model of the first generation Axial-Flow Styling dating back to 1977 

Follow the Axial-Flow Combine Story through 2100 series on Part VII 

Article by Jim Schroer 

Page Arrangement by Jason Hasert

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