Your axle is howling, your truck has a vibration under load, and the fluid you pulled out looks like metal-flake paint. Time to fix it — but the choice is bigger than most truck owners think. You can rebuild the diff with a kit, swap in complete front differentials or complete rear differentials, or just replace the worn bearings with differential bearing kits. The right call depends on what is actually damaged, how much labour time you have, and what your truck is worth fixing.
This guide walks through every option, when each one makes sense, and how to spec the right parts the first time.
A bearing kit is the box of consumables you need to do a rebuild — carrier bearings, pinion bearings, pinion seal, crush sleeve (or solid spacer), pinion nut, ring gear bolts, and shim packs. It does not include the ring and pinion themselves, the carrier (LSD or open differential case), or the housing. If your gears and carrier are still good, a bearing kit is the cheapest correct fix.
A complete front differential is the entire front axle differential assembly: housing, carrier, ring and pinion, bearings, seals, and (depending on the truck) the actuator and disconnect mechanism. Bolt the assembly to the axle tubes, drop in axle shafts, fill with fluid and you are done. Common on full-size 4×4 trucks where the front diff lives in a separate aluminum or cast iron housing.
A complete rear differential covers everything that lives inside (or attached to) the rear axle housing — sometimes sold as the third-member style “drop-in” unit (think Ford 9-inch, Dana 60 third-member designs) and sometimes as a complete axle assembly including the housing. Either way: ready to install, set up and ready to run.
Shop our differential components and bearing kits for the most common North American axles — Dana, Ford 8.8, Ford 9-inch, GM 8.5/8.6/10.5/11.5, Dodge 9.25, AAM and more.
Browse our complete front differentials selection — fully assembled, ready to bolt in, and backed by warranty.
See the full complete rear differentials catalogue — Dana 60, Ford 9-inch, GM 14-bolt and more.
Before you order anything, narrow down the problem. The wrong diagnosis is the #1 cause of repeat repairs.
Pinion bearing or set-up issue. Often fixable with a bearing kit and a careful re-shim.
Gear wear or improper backlash. If the gears are mid-life and the pattern is still readable, a bearing kit and a re-set can save them. If the gears are worn or chipped, you need new ring and pinion (or a complete diff).
Spider gears, side gears, or a failing limited-slip clutch pack. The carrier needs to come apart. If the carrier itself is damaged, a complete diff is often faster and cheaper than sourcing individual carrier parts.
Could be a driveshaft, yoke, or u-joint — not necessarily the diff. Check pinion yokes and driveshaft balance before condemning the differential.
If you are already inside the diff, this is the moment to consider a posi or locker upgrade. A limited slip posi traction unit dramatically improves traction in snow, mud, gravel, or boat ramps — without changing how the truck drives on dry pavement.
Common posi/LSD upgrades carry a meaningful price premium over a stock open carrier, but if the diff is already torn down, the labour cost is already sunk — the only extra is the part itself.
Generalizing, but typical pricing falls in these bands:
If you are paying a shop $130/hour, a complete diff often works out cheaper overall once you add up labour for a from-scratch set-up. If you are doing it yourself in a heated garage with a dial indicator and a torque wrench, the bearing kit route wins on cost.
Even with a complete diff, plan to replace:
We stock all of these alongside the rebuild parts — keep an eye on our differential components section.
The hardest part of buying a differential or a bearing kit is making sure it fits your specific axle. There are dozens of variants — gear ratio, splines, axle code, bolt pattern, ABS tone ring, sensor type — and the wrong part is an expensive afternoon.
Every product page at TransTech Canada lists the exact fitment data and ratio options. If you are unsure, send us your VIN and the axle code stamped on the differential housing and we will spec the correct complete front differentials, complete rear differentials or differential bearing kits for your truck.
Browse the full TransTech catalogue or contact us for fitment help — we ship across Canada and into the US.
Search by Vehicle 
Search by Vehicle 