Specs, fluids & service · 1984–1990

Ford Bronco II specs, fluids and service intervals

The numbers you need in the garage, on one page: spec sheet, capacities and service intervals, wheels and tires, and the parts to order. Sourced from owners, specialists and the factory; tags marked confirm in manual haven't been checked against a factory source yet.

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Spec sheet

MODEL YEARS	1984–1990 (built January 1983 to early 1990)
ASSEMBLY	Louisville Assembly Plant, Louisville, Kentucky
BODY	Two-door, four-seat wagon with a fixed roof and rear liftgate
WHEELBASE	94.0 in (2,388 mm)
LENGTH	158.3 in (1984–88) · 161.9 in (1989–90)
WIDTH / TRACK	68.0 in · 56.9 in track
FRONT AXLE	Dana 28 TTB · Dana 35 TTB (late 1990)
REAR AXLE	Ford 7.5 in · 3.45, 3.73 or 4.10
ENGINES	2.8 Cologne V6 · 2.9 Cologne V6 · 2.3 Mitsubishi turbodiesel I4
WHEELS	5 x 114.3 mm (5 x 4.5 in) · 205/75R15 stock
FUEL TANK	23 US gal
US SALES	762,976 (model years 1984–1990, per NHTSA)
REPLACED BY	Ford Explorer (1991 model year)

By year

YEARS	PLATFORM	ENGINE	OUTPUT	NOTES
1984	Launch · 4WD only	2.8 Cologne V6 (carbureted)	115 hp · 150 lb-ft	TK4 four-speed or C5 three-speed automatic. BW1350 manual-shift transfer case, Dana 28 TTB, 7.5 rear. Standard, XLS, XLT and Eddie Bauer trims.
1985	4WD only	2.8 Cologne V6	115 hp · 150 lb-ft	Five-speed manuals (TK5, FM145). A4LD four-speed automatic from November 1984 builds. Power window and lock group. Last XLS.
1986	4WD (first 2WD per Ford production records)	2.9 Cologne V6 EFI · 2.3 Mitsubishi turbodiesel I4	140 hp · 170 lb-ft (2.9)	Fuel injection, 58 mm throttle body and EGR on 1986–87 2.9s. Touch-Drive electric shift arrives late in the year. The diesel sold poorly.
1987–1988	2WD and 4WD	2.9 Cologne V6 EFI	140 hp · 170 lb-ft	Rear ABS standard from 1987. 1988: sequential injection, FM146 and Mazda M5OD five-speeds, dual-solenoid A4LD from mid-year, XL Sport trim.
1989–1990	Facelift · 2WD and 4WD	2.9 Cologne V6 EFI	140 hp · 170 lb-ft	New nose and dash, 161.9 in long, no vent windows, improved 89TM heads. XLT Plus package. 1990: BW1354 on electric-shift trucks, Dana 35 TTB after November 1989.

Fluids, capacities & service intervals

Most Bronco IIs for sale are 35-plus years old and have passed through several cheap owners, so baseline everything. On a 2.9, the cooling system is a priority, because The Ranger Station says one overheat can crack an early head, and it calls synthetic oil and good cooling maintenance essential. On a 4x4, service the transfer case with ATF, not gear oil, and inspect the TTB front end.

ITEM	SPEC / CAPACITY	INTERVAL	NOTES & PARTS
Engine oil & filter	2.9: 5.0 qt with filter (4.0 qt without) · 2.8: 5 qt with filter · grade confirm in manual	Change at purchase, then per the owner's manual confirm in manual	Check oil pressure if the valve train is noisy: The Ranger Station quotes about 20 psi at warm idle and 55 psi at 2,000 rpm for the 2.9. Look for milky residue under the filler cap.Oil filter, 1988 Bronco II 2.9 · RockAuto ↗Oil filter, 1985 Bronco II 2.8 · RockAuto ↗
Coolant, thermostat & hoses	7.2 qt (with A/C) / 7.8 qt (without A/C) per The Ranger Station · coolant type confirm in manual	Flush at purchase; fit a new thermostat and hoses if their age is unknown	The single most important item on a 2.9. Pressure-test the system and check the radiator, fan clutch and water pump.Thermostat, 1988 Bronco II 2.9 · RockAuto ↗Radiator hoses, 1988 Bronco II 2.9 · RockAuto ↗Water pump, 1988 Bronco II 2.9 · RockAuto ↗
Spark plugs, wires, cap & rotor	Motorcraft AWSF-42C gapped 0.044 in · timing 10° BTDC · firing order 1-4-2-5-3-6	Replace at purchase	These specs are listed for both the 2.8 and the 2.9. On the 2.8, check that the distributor hold-down and rotor screws are tight, because loose ones change the timing.Spark plugs, 1988 Bronco II 2.9 · RockAuto ↗Spark plug wires, 1988 Bronco II 2.9 · RockAuto ↗Distributor cap, 1988 Bronco II 2.9 · RockAuto ↗
TFI ignition module	Distributor-mounted thick-film module	Inspect at purchase; carry a spare	Heat makes it fail intermittently on a hot engine. Relocating it to a heat sink is a well-documented fix.Ignition control module, 1988 Bronco II 2.9 · RockAuto ↗
Air & fuel filters	confirm in manual	Replace at purchase; check the air filter after dusty trails	The 2.9 is fuel-injected (30–40 psi fuel pressure per The Ranger Station), so relieve the pressure before opening the lines. Recall 87V-139 added retainer clips to spring-lock fuel couplings on 1986–87 trucks.Air filter, 1988 Bronco II 2.9 · RockAuto ↗Fuel filter, 1988 Bronco II 2.9 · RockAuto ↗
Automatic transmission (A4LD)	Mercon ATF (Mercon V as the modern replacement) · ≈ 9.5 qt total	Pan drop and filter at purchase	A pan drop replaces only part of the fluid. Check the vacuum modulator line for ATF and add an auxiliary cooler. 1985–87 units are the most fragile.A4LD filter, 1988 Bronco II · RockAuto ↗Auxiliary transmission cooler, 1988 Bronco II · RockAuto ↗
Manual transmission	TK4, TK5 and M5OD: Mercon ATF · FM145 and FM146: confirm in manual	Drain and refill at purchase	Identify the gearbox from the TRANS code on the door-post label. On an M5OD, replace the three rubber top-cover plugs with steel cup plugs (Dorman 555-108 or Dana 219-3052), because leaks there can run it low.Manual transmission fluid, 1988 Bronco II · RockAuto ↗Clutch slave cylinder, 1988 Bronco II · RockAuto ↗
Transfer case (BW1350 / BW1354)	≈ 2 qt ATF: Dexron III/Mercon, Mercon V or Mercon LV per the factory manual, NOT gear oil	Drain and refill at purchase	The 2WD BW1359 pass-through case is a special case: some contain ATF and some are dry. On Touch-Drive trucks, test every mode from the buttons.Transfer case fluid, 1988 Bronco II · RockAuto ↗Transfer case output seal, 1988 Bronco II · RockAuto ↗
Front differential (Dana 28 / Dana 35 TTB)	Hypoid gear oil SAE 80W or 90W · The Ranger Station lists 2 qt (Dana 28) / 3 qt (Dana 35) confirm at fill plug	Change at purchase and after deep water	Check the slip-yoke seal on the long side and the axle vent.Gear oil, 1988 Bronco II · RockAuto ↗Differential cover gasket, 1988 Bronco II · RockAuto ↗
Rear differential (Ford 7.5)	Hypoid gear oil SAE 75W-80 or 80W-90 · ≈ 5 pints · add 2 oz friction modifier for a limited slip	Change at purchase	The axle code on the door-post label tells you the ratio and whether it's a limited slip.Gear oil, 1988 Bronco II · RockAuto ↗Limited-slip friction modifier, 1988 Bronco II · RockAuto ↗
Front hubs & wheel bearings	Wheel-bearing grease confirm in manual	Repack at purchase	Check that the bearing-adjusting nut retaining keys are present (recall 89V-109 covered trucks that left the factory without them). Replace failing automatic hubs with manual hubs.Front wheel bearings, 1988 Bronco II · RockAuto ↗Front wheel seals, 1988 Bronco II · RockAuto ↗Locking hubs, 1988 Bronco II · RockAuto ↗
TTB bushings, ball joints & steering	Beam pivot bushings · radius-arm bushings · ball joints · tie-rod ends	Inspect at purchase	Uneven tire wear is the tell. Fix camber with offset bushings, not by ignoring it.Axle pivot bushings, 1988 Bronco II · RockAuto ↗Camber/caster bushings, 1988 Bronco II · RockAuto ↗
Brake fluid	DOT 3 confirm in manual	Flush at purchase	Front discs and rear drums, with rear-wheel ABS from 1987. On manual trucks the hydraulic clutch is worth bleeding at the same time.Brake fluid, 1988 Bronco II · RockAuto ↗Brake hoses, 1988 Bronco II · RockAuto ↗

Capability

Wheelbase	94.0 in (2,388 mm)
Length	158.3 in (1984–88) · 161.9 in (1989–90)
Width	68.0 in (1,727 mm)
Height	68.2 in (1984–88) · 69.9 in (1989–90) Wikipedia infobox figures
Track	56.9 in front and rear NHTSA petition analysis, 1999
Fuel tank	23 US gal (87 L)
Seating	4
Cargo volume	23.8 cu ft behind the rear seat · 57 cu ft maximum
Low range	2.48:1 (BW1350 and BW1354)
Fuel economy	EPA 15–17 city / 17–22 hwy Factory-era ratings: a 1984 4x4 with the 2.8 and C5 automatic was 15/17; the best was a 1986–88 2WD five-speed 2.9 at 17/22

Wheels & tires

Factory tire	205/75R15 (≈ 27.1 in tall), the factory size per The Ranger Station
Bolt pattern	5x114.3 (5x4.5")
Center bore	70.5 mm
Lug thread	1/2"-20 UNF
Biggest tire · Stock	31x10.50R15
Biggest tire · 1.5 in	32x11.50R15
Biggest tire · 4 in	31–32 in (33 in with cut-out flares or a 3 in body lift)
Biggest tire · 6 in	33 in (35 in with a 2–3 in body lift and cut-out flares)

Open the Ford Bronco II in the tire fitment tool →

Common Ford Bronco II repairs

Always confirm torque figures, fluids and capacities against the factory service manual for your VIN. See the disclaimer; some parts links are affiliate links.