The PTU sends power to your rear wheels — and Ford sealed it 'for life' with less than a litre of fluid mounted beside the exhaust. We rebuild or replace it at your home before it takes the driveline with it.
The Power Transfer Unit is the small gearbox bolted to the transmission that splits torque to the rear wheels on AWD Edge, Explorer, Flex and MKX models. Ford built it with a tiny fluid capacity, no drain plug on many versions, and called the fill 'lifetime' — then mounted it inches from the exhaust. The result is predictable: the gear oil bakes into sludge, the bearings and gears run on burnt fluid, and the unit wears out years before the rest of the vehicle. Ford's own TSB 19-2017 addresses the pattern.
There's a second, quieter failure: the PTU's inner seal can let transmission fluid and PTU gear oil mix silently — no puddle, no warning — degrading both units at once. By the time symptoms surface, the damage is underway: a whine under load that climbs with speed, vibration at highway pace on the 401, a clunk when the AWD engages, and eventually a brown, burnt-smelling leak near the passenger-side axle.
Caught early — at the whine-and-leak stage — bearings and seals with fresh fluid can save the unit. Caught late, the PTU needs replacement, and a fully seized PTU can damage the transmission it bolts to. Either way, the 'lifetime fluid' label is the real culprit: these units want fluid changes the schedule never asked for.
If your Ford is doing any of these, this is the likely cause:
A whining PTU is running on baked fluid and dying bearings — and it doesn't fail in isolation. A seized unit can take the transmission's output section with it, turning a driveline repair into a transmission job. And if the inner seal is cross-leaking, your transmission fluid is being quietly contaminated right now. This is one of those failures where six months of waiting can double the bill.
Yes. The PTU is accessed from underneath, and with proper jacking equipment and supports it's well within driveway scope — no engine-out, no transmission removal in the typical case. We come to you with the unit, seals, fluid and tools, and most are done in a day.
Dealers typically quote a complete new PTU assembly at retail plus the labour to swap it — and the unit itself is an expensive part. If your unit's gears are still healthy, bearings and seals with fresh fluid can be the right repair at a different scale. We assess first, then give you one flat quote for what your vehicle actually needs.
Because 'lifetime' described the warranty period more than the fluid. The PTU holds a very small volume of gear oil mounted next to the exhaust — it cooks. Ford's TSB 19-2017 exists because of this exact pattern. The practical fix going forward is simple: change the fluid on a real schedule, which we set you up for as part of the job.
You can for a while, but you're gambling with the parts around it. The whine is bearings running on burnt fluid; the next stages are metal debris, seal failure into the transmission, or seizure. The repair scales up at each stage. At the whine stage you have options — at the grinding stage you have one, and it's the expensive one.
Send it over for a free second opinion. I'll tell you straight what the job actually involves — and if their quote is fair, I'll tell you that too.
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