Rear differential

The rear differential is the gear-filled housing at the centre of the rear axle that takes drive from the propshaft and splits it to the two rear wheels, letting them turn at different speeds through a corner. It carries the crown wheel and pinion, the spider gears, and a bath of heavy oil, and on rear- and four-wheel-drive cars it does this under the car's full power.Neglected oil, towing strain, and sheer mileage wear the gears and bearings until the unit whines, vibrates, or seizes. A rear differential that locks up at speed can throw the back of the car sideways without warning, so a noisy or leaking unit is worth dealing with before it reaches that point. Replacement tends to be the answer when:

• A whine or howl rises and falls with road speed, pointing to worn crown wheel and pinion teeth
• A rhythmic clunk on and off the throttle signals worn spider gears or backlash
• A rumble or growl through the floor traces back to collapsing internal bearings
• Oil weeping from the pinion seal or housing has starved the gears
• Metallic debris on the drain plug confirms the internals are breaking down
• The unit has overheated or seized after running low on oil

A rebuilt or used unit costs a fraction of a new one, but the listings are scattered. Parthunt24 stacks used rear differential listings from marketplaces like Ovoko, ProxyParts, eBay, and TotalParts into one feed, where 957 options can be weighed on price, condition, and fitment before any seller is contacted.

The gear ratio is the make-or-break figure: fit a differential with the wrong ratio and the speedometer, gearing, and on AWD cars the centre coupling all go out of step.Confirm the ratio first, then the OEM number, the drivetrain type (RWD, AWD, or 4WD), and whether your car runs an open or limited-slip differential, since the two aren't interchangeable. The housing design and ABS tone ring need to match the rear axle differential you're removing too.Choose your make and model on Parthunt24 to filter the results to differentials for your car. Selecting a listing forwards you to the marketplace that holds it, where you can read the seller's full description and complete the purchase.

• Vehicle make, model, and year: Differential specifications can vary between generations and facelifts.
• OEM part number: The most reliable way to confirm compatibility.
• Gear ratio: The replacement differential must match the vehicle’s original gear ratio.
• Drivetrain type: RWD, AWD, and 4WD vehicles use different differential designs.
• Engine type and power output: Different engine variants may use different differential ratios and housings.
• Transmission type: Some vehicles use different differential setups depending on the transmission.
• Limited-slip or open differential: The replacement unit should match the original specification.
• Axle and mounting points: Mounting brackets and axle connections must be compatible.
• ABS and sensor compatibility: Some differentials include speed sensors or tone rings.
• Differential housing type: Housing dimensions and mounting designs may vary between versions.

Once you're redirected to the original listing, remember that the wear inside a differential is sealed away from the camera, so the seller's account of how it ran is what you're really buying.The most telling detail is whether the unit was turning quietly under power when it came off the donor, since internal gear and bearing wear hide completely in a photograph.

• Photos: The housing, the pinion flange, the mounting points, and the casing for cracks.
• Seller reputation: Ratings, reviews, and trading history.
• Compatibility: OEM number and gear ratio matched to your car.
• Included components: Bare centre, or complete with casing, mounts, and sensors?
• Condition: Used, tested, or rebuilt? Ask about noise, play, and oil condition.
• Testing: Confirmation that the unit ran quietly with no whine or knock at removal.
• Warranty and returns: A clear policy, valuable on a part this expensive to ship.
• Shipping: A heavy unit needing crated or palletised packaging.
• Documentation: Donor mileage, gear ratio markings, and proof of removal.

With the noise history and ratio confirmed, the order goes through the seller's marketplace.

Rear differential price depends on the drivetrain, the ratio, and whether the unit is a used pull or a rebuilt rear differential. Used open differentials for common cars sell around €100-€250, limited-slip and AWD units fetch €250-€600, and rebuilt or performance differentials for premium models climb past €900.Parthunt24 lists rear differential for sale offers from as low as 5.00.What separates a cheap unit from a costly one:

• Type: Open differentials cost less than limited-slip or locking units.
• Rebuilt vs used: Rebuilt units cost more but come with fresh bearings and a warranty.
• Drivetrain: AWD and 4WD centres outprice simple RWD units.
• Ratio rarity: Common ratios stay cheap; unusual ratios are harder to find and dearer.
• Condition: Quiet, low-mileage units with clean oil take the premium.

Comparing rear differential prices is quickest with every seller's listing gathered on one Parthunt24 page.

A failing differential rarely takes the hit alone, since the parts feeding and flanking it share its loads and its oil. Debris from worn gears travels through the whole axle, so the components on either side of the differential are worth checking before the rebuild. Browse these on Parthunt24:

• CV joint: On independent rear suspension, the joints take strain from a worn differential.
• Drive shaft: Propshaft and driveshafts transmit the same loads and wear alongside.
• Wheel bearings: Rear bearings rumble in sympathy and are easy to check while in there.
• Pinion seal: A weeping seal is often the root cause; renew it whatever else is done.
• Differential fluid: Always refill with fresh oil to the correct spec after any work.
• Wheel hub: Hub and bearing wear shows up at the same time as axle noise.
• Gearbox mount: Driveline mounts let the axle move and stress the differential when worn.

A rear differential is among the priciest driveline parts to buy wrong, which makes a thorough comparison worth the few minutes it saves against a costly mistake. Parthunt24 draws the major used-parts marketplaces onto one results page, where ratio, drivetrain, and condition stand against every rear differential listed, for RWD, AWD, and 4WD cars across European marques.One search lays every seller's differential side by side, with the best price simple to spot. Compare prices, find the best deal, and buy a rear differential for your car today on Parthunt24.