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1985 GMC Truck S15 4WD

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1985 S15 4WD.

The 1985 GMC Truck S15 4WD presents a straightforward four-wheel-drive truck package equipped with an engine requiring just 3 quarts of oil across a range of viscosities including 20W-20, 15W-40, and 5W-30. Notably, the vehicle's sole recall and single owner complaint both focus on the seats rather than any powertrain concerns, underscoring a mechanically sound foundation. When viewed against the broader model complaint history spanning 1990 to 2001—where issues peaked at nine complaints in 1991 and reached their lowest at just one in 1999—this 1985 model's minimal grievance record positions it as an exceptionally stable entry in the platform's overall reliability trajectory.

Model year1992 1991 1986 1985

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity3 qtOEM · verified

Engine oil type20W-20 / 15W-40 / 5W-30OEM · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses OE oil filter 12737090. Note the factory engine air filter, fuel filter and front wiper blades are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

OE service part numbers OEM · verified

Engine oil filter	12737090 alt 12737092
Engine air filter	25040881 discontinued · alt 25041542
Fuel filter	5651803 discontinued · alt 25171792
Spark plug	05614046 alt 19300382
Front wiper blades	12363297 discontinued
Serpentine belt	14083347 alt 09433750
Thermostat	03050922 alt 03043066

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 3 qt of 20W-20 / 15W-40 / 5W-30 engine oil, 80W-90 · GL-5 in the differential, DOT 3 brake fluid.

Lubricants & capacities

Brake Fluid	DOT 3
Differential Gear Oil	80W-90 · GL-5
Differential Gear Oil Capacity	4.0 qt
Differential Gear Oil	80W-90 · GL-5
Differential Gear Oil Capacity	2.6 qt
Engine Coolant	ETHYLENE GLYCOL
Engine Oil	20W-20 · 15W-40 · 5W-30
Engine Oil Capacity	3 qt

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter at 7,500 mi; spark plugs every 15,000 mi.

Every 5,000 mi	Shift Linkage (lubricate)
At 7,500 mi	Choke System (inspect) · Distributor Vacuum Advance (inspect) · Drive Axle Assembly (drain & refill) · Early Fuel Evaporation System (inspect) · Engine Oil Filter (replace) · Throttle Body (torque)
Every 7,500 mi	Accessory Drive Belt (inspect) · Body Latches, Locks & Hinges (inspect) · Brake Line (inspect) · Brake Linings (inspect) · Brake System (inspect) · CV Joint Boot (inspect)
Every 10,000 mi	Air Intake System (inspect) · Radiator Fan Assembly (inspect) · Underbody Splash Shield (inspect)
Every 15,000 mi	Distributor Vacuum Advance (inspect) · Engine Oil Filter (replace) · Engine Valves (inspect valve lash) · PCV System (inspect) · Spark Plug Wires (inspect) · Tire & Wheel Assembly (rotate)
At 30,000 mi	Early Fuel Evaporation System (inspect)
Every 30,000 mi	Choke System (inspect) · Distributor Assembly (inspect) · Distributor Vacuum Advance (inspect) · EGR System (inspect) · Early Fuel Evaporation System (inspect) · Engine Air Filter Element (replace)
At 45,000 mi	Distributor Vacuum Advance (inspect)
At 60,000 mi	Distributor Vacuum Advance (inspect)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

Owner complaints about the 1985 GMC Truck S15 4WD dominate in one area — the seats, 1 of 1 reports (100%), well ahead of the next concern. None of this vehicle's 1 recall campaigns target the seats, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 1 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the seats pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

Open recalls

NHTSA campaigns

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

Owner complaints

1 involved a crash · 0 a fire

Owner complaints by model year NHTSA · this generation & adjacent

’90 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’01

Owner complaints filed with NHTSA, by component

All 1 complaints on record, top 1 components.

Seats1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

06E049000Exterior LightingReported 24/05/2006

CERTAIN CK MOTORSPORTS COMBINATION HEADLIGHTS, CLEAR CORNER, BUMPER, AND SIDE MARKER LIGHTS SOLD AS REPLACEMENT LAMPS FOR USE ON THE PASSENGER VEHICLES LISTED ABOVE. SOME COMBINATION LAMPS THAT ARE NOT EQUIPPED WITH… Remedy: CK MOTORSPORT WILL NOTIFY OWNERS AND REPLACE THE NONCOMPLIANT LAMPS FREE OF CHARGE. THE RECALL BEGAN ON JULY 1, 2006. OWNERS MAY CONTACT CK MOTORSPORT AT 1-909-610-7211.

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420

Catalyst system efficiency below threshold — Bank 1

P0300

Random / multiple cylinder misfire detected

P0171

System too lean — Bank 1

P0455

Evaporative emission system leak detected — large leak

P0128

Coolant thermostat below regulating temperature

P0442

Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN

Decode a VIN to confirm the transmission and build data for a specific S15 4WD. OEM

Build data

Plant, GVWR class, engine and body data for any 17-character VIN.

Recalls

Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Vehicles taking 3 qt Engine oil filter 12737090 Engine air filter 25040881 Fuel filter 5651803 Spark plug 05614046

Reference guides

Cross-vehicle references for the kinds of data on this page.

Vehicle recalls & TSBs OBD-II trouble codes Maintenance schedules Fluid capacities & specs

Frequently asked

How much oil does the 1985 S15 4WD take?

3 qt of ABOVE 40 degrees F: 30, ABOVE 20 degrees F: 20W-20, ABOVE 10 degrees F: 15W-40, BELOW 60 degrees F: 5W-30, per the factory manual.

Does the 1985 S15 4WD have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.