Not all of us are walking encyclopedias of automotive knowledge. We all know that one guy who can rattle off facts like how many '67 small-window C10s were made, but does that knowledge really matter? Well, it may not help build a truck, but it is cool to know. We wanted to give you some information that you might be able to use in the real world and hopefully help you build a better truck. With the assistance of some of our four-wheel-drive buddies, we compiled a guide to help you determine what rearend is under the truck and what lug pattern it has. This will just cover truck stuff, but that doesn't mean a car rearend can't be stuffed under your S-10. But that's a story for another day. We hope you find this guide useful, and until next month: Keep your eyes on the rearend.

TECH TIP
Axle Terminology

To prevent you from looking like a total newbie, here's some techno-jargon terms you should know when talking to the guy behind the parts counter:

Semifloating: The weight of the vehicle rides on the axleshaft, which also spins the wheel.

Full-floating: The weight of the vehicle rides on the axlehousing, and a ring of bolts in the center holds the axleshaft in place.

Integral: The ring gear and pinion gear are set up inside the differential housing.

Dropout: The carrier, or differential, can be removed as a single unit. It is also called the centersection.

Chrysler 8-1/4
This semifloating rear axle features a 10-bolt cover and appeared in various Dodge and Jeep vehicles.
Applications: '90-'00 Dakota, '72-'96 1/2-ton 2WD and 4WD Dodge fullsize, '92-present Cherokee
Ring-gear diameter: 8.25 in
Pinion-gear diameter/splines: 1.626 in/27 splines
Available gearsets: 2.71, 2.94, 3.21, 3.55, 3.90, 4.10, and 4.56

Ford 8.8
The Ford 8.8-inch is basically a 7.5 with a larger ring gear. The only way to distinguish it from the smaller unit is to look at the vehicle it's under or inspect the housing for identifying numbers.
Applications: '81-'94 Bronco, '90-1/2-'96 Explorer, '90-1/2-'92 Ranger with 4.0L engine, '81-'90 F-100, '81-'96 F-150/F-250, '97 F-150
Ring-gear diameter: 8.8 in
Pinion-gear diameter/splines: 1.626/30 splines
Available gearsets: 3.08, 3.27, 3.31, 3.55, 3.73, 4.10, 4.33, 4.56, 4.88, and 5.14

Ford 9-Inch
Appearing in almost every light truck with Ford written on the tailgate, the Ford 9-inch is one of the strongest light-axle designs around. Though production ceased several years ago, these units are still plentiful in wrecking yards, not to mention from custom-axle builders. The 9-inch is easily spotted because it uses a third member, or dropout, to house the ring-and-pinion, making it accessible from the front rather than the rear of the axle. This means there is no bolt pattern to look for, only a round hump.
Applications: '66-'88 Bronco, '57-'87 F-100/F-150/F-250
Ring-gear diameter: 9 in
Pinion-gear diameter/splines: 1.313 in/28 and 31 splines
Available gearsets: 2.80, 2.86, 2.94, 3.00, 3.10, 3.15, 3.25, 3.40, 3.50, 3.55, 3.60, 3.64, 3.70, 3.75, 3.80, 3.82, 3.89, 3.91, 4.00, 4.11, 4.22, 4.30, 4.33, 4.40, 4.50, 4.56, 4.57, 4.63, 4.71, 4.78, 4.86, 5.00, 5.14, 5.22, 5.29, 5.43, 5.50, 5.57, 5.67, 5.83, 6.00, 6.14, 6.20, 6.33, and 6.50

GM 9-1/2-INCH & 10-1/2-INCH 14-BOLT
GM produced two 14-bolt axles through the years: the 9-1/2-inch and the 10-1/2-inch (shown). The 10-1/2-inch is the stronger of the two. Both use 14-bolt covers, but the 9-1/2 is more egg-shaped (like a larger GM 7-1/2), while the 10-1/2 has straight sides and sharper corners. The 9-1/2 is an integral pinion design where the pinion is removed through the rear cover plate. The 10-1/2 is a removable pinion design, which allows the pinion to be removed from the front of the housing without pulling the rear cover. Other distinguishing features of the 10-1/2 are the 6-bolt removable pinion support and full-floating axles.
Applications: '88-'96 C10/C15/C20 (9-1/2-inch), '88-'96 K10/K15, '81-'96 K20, '73-'92 K2500/K3500 (10-1/2-inch)
Ring-gear diameter: 9-1/2 in, 10-1/2 in
Pinion-gear diameter/splines: 1.876 in/30 splines (9-1/2), 1.750 in/30 splines (10-1/2)
Available gearsets:3.42, 3.73, 4.10, 4.56, 4.88, 5.13 (10-1/2 only)

GM 12-Bolt
Two versions of the GM 12-bolt exist but have nothing more than the bolt count in common. One is a car version with a grooved cover plate, while the truck-version cover plate is raised. The 12-bolt is integral and semifloating, but isn't a big step up from the 8-1/2-inch 10-bolt because the axleshafts and housings are very similar. A drawback to both the 10- and 12-bolt axles is that the axleshafts are retained by C-clips, which, if broken, can be a serious hazard.
Applications: '64-'82 K10/K20 and Blazer
Ring-gear diameter: 8.875 in
Pinion-gear diameter/splines: 1.438/30 splines
Available gearsets: 3.07, 3.42, 3.73, 4.10, 4.56, 4.88, 5.13, and 5.38

GM 8-1/2-Inch 10-Bolt
With its round cover design, the 8-1/2-inch 10-bolt is a semifloating, integral design. Its claim to fame is that it replaced the Dana 44 in '77 when GM decided to use its own products.
Applications: '77-'87 C10/K10/K20, '80-'94 Blazer, '80-'94 C10/K10, '88-'00 K1500/K2500
Ring-gear diameter: 8.5 in
Pinion-gear diameter/splines: 1.626/28 and 30 splines
Available gearsets: 2.73, 3.08, 3.23, 3.42, 3.70, 3.73, 3.90, 4.10, 4.11, 4.56, 4.88, 5.13, 5.38, and 5.57

Toyota 8-Inch
Also referred to as a 7.8-inch (Americans rounded up the figure), two versions of the 8-inch appeared in Toyotas over the years: one for four-cylinder applications and another for the turbo four-cylinder and V-6 models. The only difference between the two is that the four-cylinder model uses shorter pinion gears. Both units are dropouts and are recognizable by the nonremovable, humped rear cover and breather tube on the top of the housing.
Applications: '79-'85 Toyota (four-cylinder model), '86-'96 Toyota, '86-'96 Toyota (turbo/V-6 model)
Ring-gear diameter: 7.8 in
Pinion-gear diameter/splines: 1.378 in/27 splines
Available gearsets: 3.70, 3.90, 4.11, 4.37, 4.56, 4.88, 5.29, and 5.71

Dana 44
The Dana 44 went into production in the late '40s and has since appeared in virtually every make of production four-wheel-drive vehicle. On the street side, the 44 found its way into some Chevys and Fords. It has a 10-bolt cover design and was produced with 30-spline axleshafts.
Applications: '60-'70 C10/15, '67-'78 F-100/F-150 4x4
Ring-gear diameter: 8.5 in
Pinion-gear diameter/splines: 1.376/30 splines
Available gearsets: 2.72, 2.87, 3.07, 3.23, 3.31, 3.54, 3.73, 3.92, 4.09, 4.27, 4.56, 4.89, 5.38, and 5.89

Dana 60 (also 50)
Looking like a larger version of the Dana 44, the Dana 60 can be identified by its 12-bolt pattern. The housing is made from nodular iron, which provides excellent rigidity and strength over other housings. Still in production today, the Dana 60 is offered in both semi- and full-floating configurations and is touted as one of the strongest and most reliable units available.
Applications: '67-'85 F-100, '67-'85 F-150, '67-'92 F-250, '78-'92 F-350, numerous Chevrolet, Dodge 3/4- and 1-ton
Ring-gear diameter: 9.75 in
Pinion-gear diameter/splines: 1.626 in/30 and 35 splines
Available gearsets: 3.33, 3.54, 3.73, 4.10, 4.56, 4.88, 5.13, 5.38, 5.57, 5.86, 6.17, and 7.17

The Final Word
Armed with this info, you should be able to know your rearends and what they fit and what gears you can get. The lug pattern sidebar should help you determine if you can stuff those sweet Escalade wheels your buddy has on your Nissan pickup.

KNOW YOUR LUGS:
FORD
YEAR MODEL BOLT PATTERN LUG NUT SIZE
'03-UP EXPEDITION 2/4WD 6 on 135 mm 14x2.00 mm
'03-UP NAVIGATOR 2/4WD 6 on 135 mm 14x2.00 mm
'00-'02 EXPEDITION 2/4WD 5 on 135 mm 14x2.00 mm
'00-'02 NAVIGATOR / BLACKWOOD 2/4WD 5 on 135 mm 14x2.00 mm
'97-'99 EXPEDITION 2/4WD 5 on 135 mm 12x1.75 mm
'97-'99 NAVIGATOR 2/4WD 5 on 135 mm 12x1.75 mm
'83-'97 RANGER / BRONCO II 4WD 5 on 4.5 in 1/2 in
'98-'04 RANGER 4WD 5 on 4.5 in 1/2 in
ALL SPORT TRAC 2/4WD 5 on 4.5 in 1/2 in
'83-'04 RANGER / BRONCO II / EXPLORER 2WD 5 on 4.5 in 1/2 in
'90-'94 EXPLORER 4WD 5 on 4.5 in 1/2 in
'95-'04 EXPLORER 4WD 5 on 4.5 in 1/2 in
'49-'96 ALL 1/2-TON PICKUP 4WD 5 on 5.5 in 1/2 in
'49-'96 ALL 1/2-TON PICKUP 2WD 5 on 5.5 in 1/2 in
'66-'96 FULLSIZE BRONCO 5 on 5.5 in 1/2 in
'97-'99 F-150 PICKUP 2/4WD 5 on 135 mm 12x1.75 mm
'00-'04 F-150 PICKUP (HERITAGE) 2/4WD 5 on 135 mm 14x2.00 mm
'04-UP F-150 PICKUP (NEW BODY) 2/4WD 6 on 135 mm 14x2.00 mm
'97-'99 F-250 LIGHT DUTY 2/4WD 7 on 150 mm 12x1.75 mm
'55-'79 F-250 / F-350 4WD 8 on 6.5 in 9/16 or 1/2 in
'55-'79 F-250 / F-350 2WD 8 on 6.5 in 9/16 or 1/2 in
'80-'98 F-250 / F-350 (OLD BODY) 4WD 8 on 6.5 in 9/16 in
'80-'98 F-250 / F-350 (OLD BODY) 2WD 8 on 6.5 in 9/16 in
'03-UP F-250 / F-350 / EXCURSION 4WD 8 on 170 mm 14x1.50 mm
'03-UP F-250 / F-350 / EXCURSION 2WD 8 on 170 mm 14x1.50 mm
'99-'02 F-250 / F-350 / EXCURSION 4WD 8 on 170 mm 14x2.00 mm
'99-'02 F-250 / F-350 / EXCURSION 2WD 8 on 170 mm 14x2.00 mm
TOYOTA
YEAR MODEL BOLT PATTERN LUG NUT SIZE
’72-’95 PICKUP 2WD 5 on 4.5 in 12x1.50 mm
’79-’95 PICKUP 4WD 6 on 5.5 in 12x1.50 mm
’96-’04 RAV4 2/4WD 5 on 4.5 in 12x1.50 mm
’93-’99 T100 2WD 6 on 5.5 in 12x1.50 mm
’93-’99 T100 4WD 6 on 5.5 in 12x1.50 mm
’95.5-’04 TACOMA 2WD 5 on 4.5 in 12x1.50 mm
’95.5-’04 TACOMA PRERUNNER 2WD 6 on 5.5 in 12x1.50 mm
’95.5-’04 TACOMA 4WD 6 on 5.5 in 12x1.50 mm
’00-’04 TUNDRA 2/4WD 6 on 5.5 in 12x1.50 mm
’64-’97 LAND CRUISER / LX450 6 on 5.5 in 12x1.50 mm
’98-’04 LAND CRUISER / LX470 5 on 150 mm 14x1.50 mm
’84-’95 4RUNNER 2/4WD 6 on 5.5 in 12x1.50 mm
’96-’04 4RUNNER 2/4WD 6 on 5.5 in 12x1.50 mm
NISSAN
YEAR MODEL BOLT PATTERN LUG NUT SIZE
’72-’03 PRERUNNER, FRONTIER, PICKUP, 6 on 5.5 in 12x1.25 mm
’72-’03 PATHFINDER, HARDBODY 2WD 6 on 5.5 in 12x1.25 mm
’72-’03 FRONTIER, PATHFINDER 6 on 5.5 in 12x1.25 mm
’72-’03 PICKUP, HARDBODY 4WD 6 on 5.5 in 12x1.25 mm
’00-’04 XTERRA 6 on 5.5 in 12x1.25 mm
DODGE
YEAR MODEL BOLT PATTERN LUG NUT SIZE
’87-’90 DAKOTA 2/4WD 5 on 4.5 in 1/2 in
’91-’04 DAKOTA 2/4WD 6 on 4.5 in 1/2 in
’98-’03 DURANGO 2/4WD 6 on 4.5 in 1/2 in
’74-’84 RAM 1500 2WD 5 on 4.5 in 1/2 in
’85-’01 RAM 1500 2WD 5 on 5.5 in 1/2 in
’74-’80 RAM 4WD W/O HUBS 5 on 4.5 in 1/2 in
’80-’93 RAM 4WD W/HUBS 5 on 5.5 in 1/2 in
’94-’01 RAM 1500 4WD 5 on 5.5 in 1/2 in
’02-UP RAM 1500 (NEW BODY) 2/4WD 5 on 5.5 in 9/16 in
’46-’81 3/4-1-TON 2WD 8 on 6.5 in 1/2 in
’82-’93 3/4-1-TON 4WD 8 on 6.5 in 1/2 in
’94-’04 RAM 2500-3500 2/4WD 8 on 6.5 in 9/16 in
CHEVROLET
YEAR MODEL BOLT PATTERN LUG NUT SIZE
’82-’03 S-10 / S-15 PICKUP 2WD 5 on 4.75 in 12x1.50 mm
’82-’03 BLAZER / JIMMY 2WD 5 on 4.75 in 12x1.50 mm
’82-’03 S-10 / S-15 PICKUP 4WD 5 on 4.75 in 12x1.50 mm
’82-’03 BLAZER / JIMMY 4WD 5 on 4.75 in 12x1.50 mm
ALL ENVOY / TRAILBLAZER 2/4WD 6 on 5 in 12x1.50 mm
’65-’87 C10 PICKUP 2WD 5 on 5 in 1/2 in
’88-’98 C1500 PICKUP 2WD 5 on 5 in 14x1.50 mm
’99-’04 C1500 PICKUP 2WD 6 on 5.5 in 14x1.50 mm
’92-’99 SUBURBAN / TAHOE 2WD 5 on 5 in 14x1.50 mm
’92-’99 YUKON / DENALI 2WD 5 on 5 in 14x1.50 mm
’92-’99 BLAZER / ESCALADE 2WD 5 on 5 in 14x1.50 mm
’00-’04 SUBURBAN / AVALANCHE 2WD 6 on 5.5 in 14x1.50 mm
’00-’04 YUKON / DENALI 2WD 6 on 5.5 in 14x1.50 mm
’00-’04 BLAZER / TAHOE / ESCALADE 2WD 6 on 5.5 in 14x1.50 mm
’69-’87 PICKUP 4WD 6 on 5.5 in 7/16 in
’88-’04 K1500 PICKUP 4WD 6 on 5.5 in 14x1.50 mm
’69-’91 BLAZER / SUBURBAN 4WD 6 on 5.5 in 7/16 in
’92-’04 SUBURBAN / AVALANCHE 4WD 6 on 5.5 in 14x1.50 mm
’92-’04 YUKON / DENALI 4WD 6 on 5.5 in 14x1.50 mm
’92-’04 BLAZER / TAHOE / ESCALADE 4WD 6 on 5.5 in 14x1.50 mm
’65-’87 3/4-1-TON C20 / C30 2WD 8 on 6.5 in 9/16 in
’65-’87 PICKUP / SUBURBAN 2WD 8 on 6.5 in 9/16 in
’65-’87 3/4-1-TON K20 / K30 4WD 8 on 6.5 in 9/16 in
’65-’87 PICKUP / SUBURBAN 4WD 8 on 6.5 in 9/16 in
’88-’04 C2500 / K2500 3/4-TON & HD 2/4WD 8 on 6.5 in 14x1.50 mm
’88-’04 C3500 / K3500 1-TON & HD 2/4WD 8 on 6.5 in 14x1.50 mm
’05-UP C1500HD / K1500HD 2/4WD 8 on 6.5 in 14x1.50 mm
’05-UP AVALANCHE 2500 2/4WD 8 on 6.5 in 14x1.50 mm
’05-UP SUBURBAN 2500 2/4WD 8 on 6.5 in 14x1.50 mm
’05-UP H2 8 on 6.5 in 14x1.50 mm
SOURCE
Auburn Gear
Auburn
IN
2-60/-925-3200
Auburngear.com
Randy's Ring & Pinion
Everett
WA
8-66/-631-0196
ringpinion.com
Currie Enterprises
7-14/-528-6957
www.currieenterprises.com
Superior Axle & Gear
N/A
superioraxle.com
Drivetrain Direct
www.drivetraindirect.com
West Coast Differentials
www.differentials.com
Moser Engineering
2-60/-726-6689
moserengineering.com
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