26 OCTOBER 20194-WHEEL & OFF-ROAD 4WHEELOFFROAD.COM
JUNKYARD AXLE SPOTTER’S GUIDE
More or less
bulletproof, these
axles are pretty
much overkill
DANA 70 & 80
Identification: Roughly D-shaped cover
with 10 bolt s, 12^5 ⁄ 8 inches wide. Often (but
not always) a “70” or “80” is cast into a
reinforcing rib of the differential housing.
Specs: 101 ⁄ 2 -inch ring gear, 3.07-7.17:1
gear ratios, 35-spline (Dana 70) 11^1 ⁄ 4 -inch
ring gear, 3.23-5.38:1 gear ratios, 35- or
37-spline (Dana 80).
Found In: Mostly the rear of various
years of Chevy, Dodge, and Ford^3 ⁄ 4 - and
1-to n t r u ck s.
The Good: More or less bulletproof,
these axles are pretty much overkill for
anything running below 44-inch tires and/
or a heavy rig with lots of horsepower.
The Dana 70 and 80 are frequently found
under the same model and year truck
depending on how the vehicle’s options
and engine, hence why we lumped them
together. Quite a few ratios and lockers
are available, though not as many as for
the Dana 60.
The Bad: All that strength comes with a
lot of weight to match , as well as reduced
ground clearance. Gear ratios and axle
upgrades are more limited compared to
other axles but still acceptable provided
you’re not doing something terribly exotic.
Notes: Dana 70s often fetch cheaper
prices than the more popular Dana 60
while providing additional strength and
are a viable choice for a budget build,
especially when purchased with a match-
ing front axle. Though rare, there were
some front Dana 70s, but strength in a
front application is comparable to a Dana- Dana 80s began production in 1988
and can be found in various light truck
and even medium-duty applications. Both
axles can be found in various industrial
applications in addition to trucks.
DANA 70 & 80FORD
FORD 8.8
Identification: A roughly square dif-
ferential cover retained with 10 bolts, 11
inches wide.
Specs: 8.8-inch ring gear, 28- or
31-spline, 2.26-5.13 gear ratios, semifloat-
ing C-clip axles, five-lug.
Found In: Rear of 1982-2012 F-150,
1982-96 Bronco, 1991-2001 Explorer,
1991-2011 Ranger (4.0L only).
The Good: One of the most widely pro-
duced axles Ford ever made, the 8.8 is an
excellent choice for any mild or moderate
trail vehicle. They are extremely plentiful
and cheap in junkyards while being well
supported in terms of gear ratios, differen-
tials, and axleshaft upgrades.
The Bad: Axles are retained by C-clips,
enabling a tire and wheel to separate
from the vehicle in the event of a broken
axleshaft. A few truck 8.8s came with
28-spline axles, so buyer beware. One
could confuse an 8.8 with the lighter-duty
Ford 7.5, as the cover is roughly the same
shape as an 8.8 but is 1^1 ⁄ 4 inches narrower.
Notes: A Ford 8.8 from an E xplorer is pretty
much the go -to budget axle swap of choice
to replace the Dana 35 in several Jeep appli-
cations. They are within 2 inches of stock
width on XJ,s TJs, and ZJs and have the same
5-on-4^1 ⁄ 2 bolt pattern. Even though the axles
are held in place with C-clips, we’ve found
axleshaft failures are exceedingly rare, evenwith stock shafts. If that’s a concern, C-clip
eliminator kits are available.FORD 8.8FORD 9-INCH
Identification: Dropout-style centersec-
tion with 10 bolt s.
Specs: 9 -inch ring gear diameter, 28- or
31-spline, 3.00-6.50:1 gear ratios, five-lug.
Found In: Rear of 1966-1983 Broncos and
1957-1986 F-100s and F-150s; various cars
from the 1950s through the early 1980s.
The Good: The Ford 9-inch is a popular,
strong, and well-supported axle. Much of
the axle’s strength for its compact size is
attributed to a third bearing used on the
nose of the pinion that prevents pinion
deflection under heavy loads. The sky’s
the limit in terms of upgrades, from 31-,
35-, and 40-spline axleshafts to nodular
iron housings to just about any popular
locker or limited-slip.
The Bad: Early 9-inch axles were
plagued with 28-spline axleshafts that
are fairly weak, but these can be upgraded
to 31-spline without much trouble. The
pinion sits low on a 9-inch centersection,
making the rear driveshaft a bit more
vulnerable than other applications. Last
manufactured in the mid-1980s, junkyard
9-inch axles are still out there but getting
harder to find. Also, don’t confuse a 9-inch
with an earlier 8-inch that was used in
some 1960s car applications; the easiest
way to tell is that the bottom two bolts on
a 9-inch require a socket to remove, while
all of an 8-inch axle’s centersection bolts
can be accessed with a wrench.
Notes: The 9 -inch is an excellent
choice because it offers a lot of strength
in a lightweight package compared to
other axles. The stamped steel housings
are lighter than many cast differentials
with heavy-wall tubing, and thanks to
the aftermarket, a 9-inch can be built to
handle just about anything. The initial
popularity of the 9-inch is largely due to
its dropout-style centersection, which
is attractive to drag racers because the
design enables quick gear ratio changes.FORD 9-INCH