Model Spotlight

Case 680E Construction King Backhoe Loader: Specs, Parts & Common Issues

The first major platform refresh of the 680 line. Produced 1975–1978, the 680E moved the family from the 301-class engine of the 680C up to the larger Case 336 cu in (5.5 L) four-cylinder diesel — 80 HP, more torque, and the Borg-Warner T19 four-speed manual transmission. Sister-launch update with the 580C in Case's smaller-frame line.

BT

Broken Tractor Editorial Team• Updated May 2026• 8 min read

The Case 680E is the first major platform refresh of the 680 line. It came to market in 1975, replacing the 680C, and ran through 1978 before the 680G took over the larger-frame slot. The defining 680E change is the engine: Case stepped up from the 301-class four-cylinder diesel used on the 680C to the larger 336 cu in (5.5 L) four-cylinder diesel. The 80 HP rating represented a meaningful jump in output over the 680C's 74 HP, but more importantly the larger displacement delivered substantially more torque under load — the trait that defines the 680E's reputation as a stronger digger than its 680C predecessor.

Alongside the engine update, the 680E moved to the Borg-Warner T19 four-speed manual transmission — a heavy-duty truck-grade gearbox that became the standard powertrain for the 680E and 680G. The T19 is shared with several Case industrial machines of the era and remains supportable through Borg-Warner aftermarket channels. The 680E retained 2WD layout, outboard-planetary final drives, hydrostatic power steering, and an open-center hydraulic system.

At-a-glance specifications

The 336 cu in engine — what changed from the 680C

Stepping from the 680C's 301 cu in 4.9 L engine to the 680E's 336 cu in 5.5 L engine represented a step up in the Case industrial engine family. The 336 maintains the same general four-cylinder architecture, in-line Bosch injection pump, and direct-injection combustion as its predecessor, but with a larger bore and stroke combination to grow the displacement. Power went from 74 HP to 80 HP, and torque under load improved noticeably.

The 336 also continues onto the 680G — the 680E and 680G share the same engine family, with the 680G's 88 HP gross rating coming from calibration and induction changes rather than a fundamental displacement change. That cross-fit is reflected in the catalog: the L72507 radiator and L55247 main hydraulic pump both carry "680E, 680G" fitment.

Borg-Warner T19 4-speed transmission

The 680E and 680G both use the Borg-Warner T19 four-speed manual transmission as the standard powertrain — a meaningful change from the power shuttle system used on the 680CK, 680B, and 680C. The T19 is a heavy-duty truck-grade transmission well known for its durability; it's been used in everything from Ford F-series pickups to industrial applications across the 1970s and 1980s.

For a backhoe loader, the T19 layout means the operator works with a clutch pedal and a standard four-speed forward / four-speed reverse pattern. No power shuttle, no torque converter. The trade-off is simpler mechanics with fewer hydraulically actuated wear items, at the cost of slower direction-change cycles during backhoe trenching where rapid forward / reverse cycling is needed.

Hydraulic system

Open-center, gear-pump hydraulics continued from the earlier 680 platforms but with refinements at the 680E. The 680G later increased combined flow significantly (to ~45 gpm); the 680E's combined flow runs slightly lower in the high-20 gpm range from the main pump alone, with the loader pump adding a portion when both functions are active. The L55247 main hydraulic pump in our catalog is the verified replacement for both 680E and 680G.

Parts we carry

The 680E is over 45 years old. Parts availability is moderate — better than the launch 680CK / 680B / 680C era because more of the 680E's components cross to the later 680G. The items below are available at Broken Tractor with verified 680E fitment.

Common issues and what to expect

336 ci engine head and gasket wear

Same age-related issues as the 267 and 301 engines on earlier 680s. Pre-combustion chamber cracks, head gasket failures, and warping from past overheating are all expected on any unrestored 680E. Plan on a full top-end rebuild as a baseline restoration step.

T19 transmission wear

The T19 is durable but does wear. Common failure modes: synchronizer wear (causes hard shifting), input shaft bearing failure (whining noise that changes with clutch position), and main shaft spline wear over time.

Torque converter wear (optional configuration)

Machines built with the optional torque converter package have an additional wear item. Symptoms of converter wear: engine bogging under load, slow takeoff from a stop, abnormal heat in the bell housing area. The L77848 rebuilt torque converter is the right replacement.

Hydraulic cylinder seal failure

Every cylinder on a 680E has seals that are 45-plus years old. Plan on rebuilding every cylinder as part of any restoration. Bores are typically still good.

Cab glass cracking (cab-equipped machines)

Cab-equipped 680E machines share some glass with the 680H / 780 series of the same era. Inspect weather seals annually as the original rubber dries and cracks.

Where it sits in the 680 family

The 680E opens the second-generation 680 platform — the post-CK-suffix era where Case dropped the Construction King "CK" nomenclature from the model name. It established the 336 cu in engine and Borg-Warner T19 transmission that defined the 680E and 680G. After 1978 the 680G took over with the same engine but higher output rating; then the 680H in 1982 with further refinements; then the 680K and 680L closing out the line in the 1980s and 1990s.