How To Set Up Ring and Pinion Rear Gear Set Swap Ford 9″ Overview Tutorial Tech Installation
How To Set Up Ring and Pinion Rear Gear Set Swap Ford 9″ Overview Tutorial Tech Installation

Announcer: Brought to you by JEGS. Man: There are a lot of good reasons for changing
your final drive ratio by swapping the ring and pinion gears. Straight performance in
racing vehicles can benefit from a gear set that improves acceleration and optimizes the
transmission’s ratios. Off-road enthusiasts can change to a final drive ratio that matches
larger tires and gives better low-end torque. And anyone who toes will appreciate gearing
that lets them conquer grades without constant hunting between gears to maintain momentum. Whatever your reasons for changing the final
drive ratio in your vehicle, the job requires some specialized tools and techniques to do
it right. A ring and pinion set that are installed incorrectly can lead to noise, premature wear,
and even driveline failure. While the process isn’t out of reach of the well-equipped do-it-yourselfer,
it takes attention to detail, patience, and the right tools. Whether you choose to tackle
the job yourself or leave it to the pros, there are some basic concepts you should be
familiar with. Follow along as we give you the knowledge
you’ll need to understand what goes into a ring and pinion swap. There are two main types
of solid axle assemblies. Most commonly, the axle assembly will mount the differential
carrier, ring gear, and pinion inside the housing, accessed by removing the differential
cover. Other types, most notably the Ford nine-inch, Chrysler eight and three-quarter
inch, and Toyota truck axles have their differential mounted in a removable carrier or third member.
No matter how the axle assembly is designed, the fundamentals of setting up the ring and
pinion are the same. To begin, the axle shafts must be disengaged
from the differential. On axle housings without a separate third member, axles are often retained
by clips on the differential end, while two-piece housings usually use retention via the bearing
at the outside end. To demonstrate installing a new ring and pinion, we’ll be using the
third member from a Ford nine-inch rear end, but the principles are the same no matter
what type of axle you are working on. When removing the existing gear set from the
carrier, make a note of the shims used on both the pinion gear and the differential
if applicable so that you have a starting point for the reassembly. Removing the old
ring gear and installing the new one may require a certain amount of persuasion and sometimes
heat. There are four basic elements to ring and pinion setup: pinion depth, ring gear
backlash, pinion bearing preload, and carrier bearing preload. In order to accurately establish these settings,
in addition to the basic hand tools, there are some specialized tools that are required,
as well as parts kits specific to your application. When ordering your ring and pinion set, don’t
forget to ask your JEGS performance specialist about setup kits, which provide the shims,
seals, bearings, crush sleeves, and other components required to do the job right. The tools you’ll need include a dial indicator
and magnetic stand, a pinion depth gauge such as JEGS part number 81655 Universal Pinion
Tool Kit, gear marking compound, and a torque wrench calibrated in inch-pounds. The first
two settings we’ll tackle are pinion depth and backlash. Pinion depth is a measurement
of how close the pinion is to the center line of the ring gear, while backlash has to do
with how close the ring gear is to the pinion. Both these dimensions are set to position
the pinion and differential assembly relative to each other and to the carrier. In theory,
pinion depth is constant for any particular axle type, but in practice it will need to
checked and adjusted. The JEGS Universal Pinion Tool Kit allows you to quickly establish the
pinion depth and set it to the factory spec. When using a crush sleeve instead of shims
on the yoke side of the pinion, leave the crush sleeve out while setting initial pinion
depth. It’s a one-time-use component and always use
a new crush sleeve for final assembly. Once the initial pinion depth is set, you can establish
backlash. Temporarily install the differential onto the carrier using the previous shims
or marks for the threaded adjusters as a starting point. Then using a dial indicator with a
magnetic face, set the indicator shaft perpendicular to a gear tooth and zero the dial. With the
pinion yoke secured, try to rotate the ring gear and measure the amount of movement. Move shims or turn the adjusters until the
backlash is within the specified range for your axle type, moving the ring gear closer
to the pinion to decrease backlash and away from it to increase it. Once the pinion depth
and backlash are set to their proper specs, it’s time to confirm them by checking the
pattern of gear engagement. Gear marking compound placed on the front and back of three or four
teeth and a couple of spots on the ring gear records the contact pattern as the gears are
rotated. By analyzing the pattern, you can determine
whether pinion depth is correct or if it needs further adjustment. If the pinion depth requires
a large adjustment, be sure to recheck backlash and adjust as necessary, then check the pattern
on the gear teeth again. Pinion bearing preload is measured by determining the amount of effort
required to turn the pinion in the bearing using a torque wrench to measure drag and
inch-pounds. Shimmed pinions should start with the old
shim stack with the pinion nut gradually brought up to the specified torque as you check the
preload to ensure you don’t damage the bearing if the shim stack isn’t thick enough. For
crush sleeves, there will be very little preload until the bearings meet the races and will
then rise rapidly. If you over-torque the pinion, it’s critical that you start over
with a new crush sleeve. When it comes to setting carrier preload,
axles with a dropout carrier will use adjuster screws in an appropriate specialty spanner
wrench, while an integrated carrier axle will use the same shims that set backlash to establish
preload. A good rule of thumb for shimmed carriers is to use a shim stack tight enough
to require a plastic dead blow hammer to install. On dropout carriers, the final preload adjustment
after setting the backlash should be done on the left side adjuster, since under load,
the forces on the pinion and ring gear will try to separate them. Once these four main
adjustments are set, you’re ready to put the carrier like the one we’ve shown back into
the axle housing and reinstall the axle shafts or replace the axles and put the cover back
on an integral carrier housing. When working with an axle housing with a dropout
carrier, be aware of the fact that some aftermarket ring gears may be large enough to contact
the back of the housing. So if you encounter excessive resistance to rotation once the
axle is reassembled, your housing may need to be clearanced slightly. When you refill
the axle, don’t forget that some types of limited slip differential require a specific
friction modifier or additive for the gear oil in order to operate properly. As you can see, having the right tools and
techniques is essential. Whether you decide to take on a ring and pinion gear change yourself
or have a professional do the work for you, you can depend on JEGS for all the hardware
you’ll need. For more information, visit us on the web at or order toll-free
24 hours a day at 1-800-345-4545. Announcer: Brought to you by JEGS.

5 thoughts on “How To Set Up Ring and Pinion Rear Gear Set Swap Ford 9″ Overview Tutorial Tech Installation”

  1. snail5341 says:

    very complicated instructions

  2. Vaios Kaliakoudas says:

    Are the metric units option on these tools shown at 3:35 available?

  3. Trey haberman says:

    great video, still trying to find a more specific way to set carrier preload other than that you should need to hammer in the shims. any advice?

  4. Jon R says:


  5. David Norris says:

    Thanks Alot guys! Huge help!!

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