Ford Bronco
1980–86

Factory gearing, tires, angles and brakes for the Bronco, and what the usual upgrades do to it. Every number is from the maker's own figures unless the calculators say otherwise. A few figures here are still waiting on a factory document; the calculators mark them.

Use this truck in the calculators

104.7 in wheelbase · 28.7 in front · 44.3 in rear overhang

Stock tireP215/75R1527.7 in tall

Axle ratio3–4.1Factory, by trim

Crawl ratio73.8:1Best trim: 1983-86 std P215/75R15SL, 8.8 rear

Angles37.6 · 22.9 · 22.7°Approach, breakover, departure

Clearance9.6 in9.1 to 9.6 in by trim

Highway mpg13EPA, 15 with the manual

Tire upgrades, worked out

1980-82 std P215/75R15, 300 Six/302/351, 9 in rear, 3s, from P215/75R15

Tire	Height	Under the diffs	Speedo at 65	RPM at 65	Gears for daily	Open
235/75R15	28.9 in	+0.6 in	62 mph	2,270	Keep 3s	Open →
31x10.50R15	31.0 in	+1.7 in	58 mph	2,114	3.73	Open →
32x11.50R15	32.0 in	+2.2 in	56 mph	2,048	3.73	Open →
33x10.50R15	33.0 in	+2.7 in	55 mph	1,986	3.73	Open →
33x12.50R15	33.0 in	+2.7 in	55 mph	1,986	3.73	Open →

Stock turns 2,367 rpm at 65 in top gear. Flotation sizes are nominal; most measure a little short mounted.

Trims

4 we have figures for

Trim	Tire	Transmission	Axle	Angles	Clearance	Open
1980-82 std P215/75R15, 300 Six/302/351, 9 in rear	P215/75R15	4-speed manual, 4-speed manual, 4-speed overdrive manual, 3-speed automatic	3 / 3.5	37.6 · 22.9 · 22.7	9.6 in	Use →
1983-86 std P215/75R15SL, 8.8 rear	P215/75R15	4-speed manual, 4-speed manual, 4-speed overdrive manual, 4-speed overdrive manual, 3-speed automatic, 4-speed automatic overdrive	3.55 / 4.1	34.3 · 20.4 · 20.7	9.2 in	Use →
1983-86 optional P235/75R15XL	P235/75R15	4-speed manual, 4-speed manual, 4-speed overdrive manual, 3-speed automatic, 4-speed automatic overdrive	3.55 / 4.1	34.1 · 20.2 · 20.6	9.1 in	Use →
1983-86 optional 10R-15C LT (and Australian XLT option '10x15') (10R-15C (10-15LT, about 31x10) tires)	31.0	4-speed manual, 4-speed manual, 4-speed overdrive manual, 3-speed automatic, 4-speed automatic overdrive	3.55 / 4.1	34.3 · 20.4 · 20.7	9.2 in	Use →

Size

Wheelbase: 104.7 in
Front overhang: 28.7 in
Rear overhang: 44.3 in
Height: 74 in
Body: SUV
Stock tires: 31.0, P215/75R15, P235/75R15

Transmissions and low range

4-speed manual (New Process 435): 6.69 · 3.34 · 1.79 · 1
4-speed manual (Warner T-18/T-19): 6.32 · 3.09 · 1.69 · 1
4-speed overdrive manual (Tremec T170FS SROD, 300/302): 3.25 · 1.92 · 1 · 0.78
4-speed overdrive manual (Tremec T170FT TOD, 351W): 3.01 · 1.78 · 1 · 0.78
3-speed automatic (C6): 2.46 · 1.46 · 1
4-speed automatic overdrive (AOD, 302 EFI, about 1985-86): 2.4 · 1.47 · 1 · 0.67
Low range, np208: 2.61:1
Low range, bw1345: 2.69:1

Axles

Front: Dana 44 Twin Traction Beam (3550 lb, 3800 lb HD)
Rear: Ford 9 in (1980-82), Ford 8.8 in (1983-86), 3750 lb
3 ratio: 1980-82 std P215/75R15, 300 Six/302/351, 9 in rear
3.5 ratio: 1980-82 std P215/75R15, 300 Six/302/351, 9 in rear
3.55 ratio: 1983-86 std P215/75R15SL, 8.8 rear, 1983-86 optional P235/75R15XL, 1983-86 optional 10R-15C LT (and Australian XLT option '10x15') (10R-15C (10-15LT, about 31x10) tires)
4.1 ratio: 1983-86 std P215/75R15SL, 8.8 rear, 1983-86 optional P235/75R15XL, 1983-86 optional 10R-15C LT (and Australian XLT option '10x15') (10R-15C (10-15LT, about 31x10) tires)
Ratios made for it: 3.73 · 4.1 · 4.56 · 4.88 · 5.13

Brakes

Front rotor: 11.72 in, 298 mm
Front caliper piston: 73.0 mm
Rear drum: 11.03 in, 280 mm
Rear: drum

Suspension

Front: Twin Traction Beam, radius arms, coil springs
Rear: leaf springs, solid axle
Rear layout: Leaf springs

Fuel economy

EPA highway, automatic: 13 mpg
EPA highway, manual: 15 mpg
Rated years: 1984–1986, 4WD

Brake upgrades

What bigger tires need →

Desolate Motorsports 80-96 Bronco / 4WD F-150 big front brake kit+13% brake torque11.7 → 13.0 in rotor · 4-piston · 16 in wheels or bigger · $1,900Base price; $1,899.99 to $2,147.99 with optional studs and lines. Offered in 80-92 and 93-96 versions. The listing says it does not fit the 1987 integrated hub design.
DIY twin-piston swap: F-250 caliper mounts with a machined Ram 1500 rotor+9% brake torque11.7 → 12.6 in rotor · 2-pistonOne-off build, photos gone from the thread.

Aftermarket bumpers

2 listed

Makers almost never publish angles, bottom heights or how far a bumper tucks, so these fill in as owners measure them. Measured yours? Add it on the rig page and every owner of this Bronco sees how it does on their tires and lift.

Front 1

OER 1980-86 Ford F150/F250/F350, Bronco Front Bumper w/o Impact Strip Holes, Chrome (TR17757S1)$281

Rear 1

Affordable Offroad fullbroncorear Ford Bronco 1980-1996 Elite Rear Bumper Full Size60 lb · $885

Every calculator, set up for the Bronco

Tire sizeBigger tires: speedo, clearance, angles and brakes.Compare tires RegearHighway RPM on every ratio and mpg.Pick your gears Crawl ratioHow slow it creeps, against other trucks.Work out crawl SpeedometerWhat it really reads on new tires.Fix your speedo LinksAnti-squat and what a lift does to it.Check your links Your rigBuild sheet and measured angles.Start a build sheet LeaderboardsWhere the Bronco ranks against every stock truck.See where it ranks

Source: archive.org. The 8.8 in rear uses two carrier series split around 3.08/3.27, so moving from a 3.00/3.08 truck to 4.10+ needs a different carrier; the TTB Dana 44 front gears are standard-rotation Dana 44 sets.

Use at your own risk. These calculators are here to help you plan and to inform your decisions, not to sign off on a build. Many numbers are estimates worked out from factory figures, and some factory figures are not yet confirmed. Check every number against your own truck, its manuals and a qualified shop before you buy parts, cut, weld, lift, regear or drive on it. Long Range Desert Tools is not liable for anything you do based on these calculators or their results. The full terms are in our policies.

Ford Bronco1980–86