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Jeep CJ-7
1976–79

Factory gearing, tires, angles and brakes for the CJ-7, 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
93.5 in wheelbase · 23.5 in front · 30.9 in rear overhang
in
Axle ratio3.54–4.09Factory, by trim
Crawl ratio51.7:1Best trim: 304 V8 / towing axle, manual (H78-15 tires)
Angles45 · 17 · 35°Approach, breakover, departure
Clearance6.9 inFactory figure
Highway mpg10Estimate, not EPA rated

Trims

3 we have figures for
TrimTireTransmissionAxleAnglesClearanceOpen
Base, 258 six, manual, Dana 20 (H78-15 tires)28.3Tremec T-150 3-speed manual, Borg-Warner T-18A 4-speed manual3.5445 · 17 · 356.9 inUse →
304 V8 / towing axle, manual (H78-15 tires)28.3Tremec T-150 3-speed manual, Borg-Warner T-18A 4-speed manual4.0945 · 17 · 356.9 inUse →
Automatic with Quadra-Trac (optional low range) (H78-15 tires)28.3GM Turbo Hydra-Matic 400 3-speed automatic3.54 / 4.0945 · 17 · 356.9 inUse →

Size

Wheelbase
93.5 in
Front overhang
23.5 in
Rear overhang
30.9 in
Height
69 in
Body
Short wheelbase SUV
Stock tires
28.3

Transmissions and low range

Tremec T-150 3-speed manual
2.99 · 1.75 · 1
Borg-Warner T-18A 4-speed manual (wide ratio, 6.32 granny)
6.32 · 3.09 · 1.69 · 1
GM Turbo Hydra-Matic 400 3-speed automatic
2.48 · 1.48 · 1
Low range, dana 20
2:1
Low range, quadra-trac bw1339 (with low range)
2.57:1

Axles

Front
Dana 30 - unverified
Rear
AMC 20 (two-piece axle shafts) - unverified
3.54 ratio
Base, 258 six, manual, Dana 20 (H78-15 tires), Automatic with Quadra-Trac (optional low range) (H78-15 tires)
4.09 ratio
304 V8 / towing axle, manual (H78-15 tires), Automatic with Quadra-Trac (optional low range) (H78-15 tires)

Brakes

Front rotor
11.75 in, 298 mm
Front caliper piston
78.6 mm
Rear drum
10.00 in, 254 mm
Rear
drum (10 in)

Suspension

Front
solid axle on leaf springs
Rear
leaf springs, solid axle
Rear layout
Leaf springs

Fuel economy

Highway, not EPA rated
about 10 mpg
Where it comes from
Owner average, 15 trucks, mixed driving (1979 CJ7 (7x 304 V8, 7x 258 six, mixed manual/auto))

Aftermarket bumpers

17 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 CJ-7 sees how it does on their tires and lift.

Front 10

Rear 7

Every calculator, set up for the CJ-7

Tire sizeBigger tires: speedo, clearance, angles and brakes.Compare tiresRegearHighway RPM on every ratio and mpg.Pick your gearsCrawl ratioHow slow it creeps, against other trucks.Work out crawlSpeedometerWhat it really reads on new tires.Fix your speedoLinksAnti-squat and what a lift does to it.Check your linksYour rigBuild sheet and measured angles.Start a build sheetLeaderboardsWhere the CJ-7 ranks against every stock truck.See where it ranks

Source: auto-brochures.com.

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.