BMW Electric Tow Hitch Not Working? Motor Runs but Arm Won't Move – Gear Fix (71606795730)

You press the tow hitch button in the boot, the motor whirs — and the ball just doesn't move. Or it swings halfway and stops, or the button light keeps flashing. On a BMW with the electric folding (swivelling) trailer hitch this is a very common fault, and in many cases the cause is not the motor or the electronics but two small plastic gears inside the drive unit. This guide explains how to recognise the problem, how to confirm it, and which part you need: the gear set 71606795730 (also listed as 303362321012 and 333030637032).

Which BMWs use this electric trailer hitch?

The electrically swivelling tow bar, where the ball arm folds away under the rear bumper at the press of a button, was offered on many BMW models. This gear set is listed for:

• BMW E60 5 Series Saloon (2003–2010)
• BMW E61 5 Series Touring (2004–2010)
• BMW E83 X3 (2003–2010)
• BMW F26 X4 (2014–2018)
• BMW F10 / F11 5 Series and G30 / G31 5 Series, which are also named in the application data

Always compare the reference on your own hitch mechanism before ordering. Different hitch suppliers and production years can use different drive units.

Symptoms of worn or broken hitch gears

• The motor runs but the ball arm doesn't move — the clearest sign that the gear teeth are stripped and the motor spins freely.
• The arm stops halfway or only moves when you help it by hand.
• Grinding, clicking or ratcheting noises from behind the rear bumper while the hitch operates.
• The arm doesn't lock in the towing position, and the indicator light in the boot keeps flashing instead of staying on.
• A "trailer hitch" fault message on the dashboard after the mechanism fails to reach its end position.

If you hear nothing at all when you press the button, check the fuse, wiring and control module first. A dead silent hitch is usually electrical; a hitch that hums or clicks but doesn't move is usually mechanical.

Why the gears fail

The drive unit uses a small electric motor and a reduction gear train to move a heavy steel arm. Over the years the plastic gears face road salt, water, temperature swings and repeated load, especially when the arm is blocked by ice or dirt, or pushed by hand while the motor is driving it. Eventually the teeth wear or snap. The motor, the arm and the lock are often still fine, and only the gears need to be replaced.

Repair instead of replacing the whole hitch

A complete new electric tow bar assembly from the dealer is expensive, and many workshops only offer the full unit. Replacing just the gears is often enough to bring the original hitch back to life, for a fraction of the cost.

Our gear set for the BMW electric trailer hitch (71606795730) contains 2 replacement gears for the hitch mechanism. It is a repair part, not a complete hitch assembly.

OEM and cross-reference numbers

Search for any of these numbers on your old gear, the drive unit label or in a parts catalogue:

• 71606795730 (BMW)
• 303362321012
• 333030637032
• P1-05890-01
• 333075 (333 075)
• 0JS-520-15
• P46GF50

How to confirm the fault before ordering

1. Listen while someone presses the button. Motor noise without arm movement points to the gears.
2. Check that nothing blocks the arm — ice, mud, a stuck trailer socket cover or a damaged bumper trim.
3. Remove the drive unit (usually behind the rear bumper or under the boot floor, depending on the model) and inspect the gears through the housing. Missing or rounded teeth confirm the diagnosis.
4. Compare the gears with the photos and references in the product listing.

Fitting tips

• Disconnect the drive unit's plug before working on it, and note how it is mounted before you remove it.
• Take photos at every step while opening the gearbox housing so the gears and any springs go back in the same position.
• Clean out the old grease and broken plastic pieces completely — loose fragments can jam the new gears.
• Use a plastic-safe grease on the new gears.
• After fitting, run the hitch through a few full cycles and check that it locks firmly in the towing position before you tow anything.

If you are not comfortable working on a safety-related part, ask a workshop to fit the gears. The tow bar must lock properly before you tow.

How to make the new gears last

• Never force the arm by hand while the motor is running.
• In winter, clear ice and snow around the ball arm before swinging it out.
• Operate the hitch now and then, even if you rarely tow, so the mechanism doesn't seize.

Frequently asked questions

Is this a complete trailer hitch?

No. It is a set of 2 replacement gears for the drive mechanism of the BMW electric folding trailer hitch.

Will it fit my BMW X5 or other models?

The listed fitments are E60, E61, E83 X3, F26 X4, F10, F11, G30 and G31. For other models, compare the part number on your existing mechanism with the references above, or contact us with a photo of your old gears.

My hitch makes no sound at all. Will new gears fix it?

Probably not. No sound usually means a power, fuse, wiring or module problem. The gears are the likely cause when the motor runs but the arm doesn't move.

Get your tow hitch working again

A stripped gear shouldn't mean replacing the whole tow bar. Order the BMW trailer hitch gear set 71606795730 and repair the mechanism you already have.