ARB Dana 60 35 Spline 4.56 Up Air Locking Differential - RD166

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  • ARB 4x4 Accessories | Part Number: ARBRD166
  • Popular Axle Manufacture:Dana
  • Axle Location:Rear|Front
  • Fitment:Universal Fit
  • Axle Type:Dana 60
  • Availability:In Stock
  • Axle Spline:35 Splines
  • Differential Type:Selectable Locker



The ARB Air Locker is a pneumatic locking differential that uses air to facilitate the locking of both axles. This action converts your differential from a conventional open to a full spool type axle supplying 100% power to both wheels to keep you going through the worst terrain. ARB onboard air compressor required to activate Air Lockers. Sold Separately.

Customer Reviews

5.0 5.0
1 Customer ratings
5.0 Instant Traction

I had this locker installed in my Dodge Ram Dana 60s, both front and rear, in the fall of 2008 and have zero complaints or complications. I upgraded my shafts to 35 spline units at the same time to avoid future costs and get ultimate strength. Adding a selectable locker like the ARB gives you instant traction when needed and the convenience of unlocking the unit for better turning radius, less wear/maintenance and maximum control. For vehicles that drive on pavement, this means less tire wear, no chirping, less axle shaft stress and safer operation in low traction situations (ice, rain, etc.) No special diff covers or complicated cables or levers!

from Tulsa, OK |


Question & Answers

7 Answered questions

Q: Hello. Im not sure what "and up" refers to: up in number/lower ratio or up in ratio? So will 3.55s work? Thanks Answer this question

A: USE: ARB Dana 60 35 Spline 4.10 Down Air Locking Differential - PN: ARBRD167

Answered by Dave from 4WP HQ on 12/14/2021

Q: will this work with 5.38 gears Answer this question

A: The ARB Dana 60 35 Spline 4.56 Up Air Locking Differential - RD166 will work with 5.38 R&P.

Answered by Dave from 4WP HQ on 11/03/2021

Q: What set 5.13 ring and pinion can be used with this carrier? It is going in a 2017 F250 front Dana 60 short pinion reverse cut. All the gear sets say to use a 4.10-down carrier. Thanks! Answer this question

A: In 2017 the Ford F250/F350 received a new Dana 60 SHORT Pinion High Pinion front end. This front requires a 4.56 and numerically higher carrier such as the ARBRD166. It will require a Short Pinion High Pinion type ring and pinion which is only made up to a 4.88 ratio. This new front end uses different pinion bearings and associated parts on the pinion than the earlier Dana 60 front end. The 2017 F250 can be equipped with a 12 bolt Sterling 10.5” rear end which can be regeared to a 4.88 ratio to match the front. Some of the heavier GVWR 2017 F250 trucks have the larger Dana M275 rear diff and the highest numerical ratio is 3.73.

Answered by Kelly from 4WP Corporate Headquarters on 06/24/2021

Q: Does this kit come with an air hose? Answer this question

A: Hello Trent Yes it has the hose and fittings along with the solenoid to control the air to the unit. Thanks

Answered by Rody on 08/27/2015

Q: I have just installed 4.88 gears in my 2000 F-250 SD. Will this fit my Dana 50 front diff? Answer this question

A: Hello James, Thank you for the question. This will not fit the Dana 50 axle. The correct ARM Locker part number for the Dana 50 is ARBRD158

Answered by RK on 06/22/2014


ARB has been manufacturing 4x4 parts for over 40 years. ARB Air Lockers will amplify the traction of your 4x4 on challenging trails. They give the off-road driver what you need in traction, control and performance. ARB believes in its products so it offers a five year, unlimited mile warranty across the air locker range. ARB 4x4 Accessories includes the suspension system brand Old Man Emu, maker of premium off-road shock absorbers. Old Man Emu premium shocks are developed and tuned specifically for each vehicle application. They come complete with vehicle specific mounting kits for fuss free installation. ARB parts are all developed, engineered and fabricated in-house in Australia. Shop ARB 4x4 Accessories Now


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