This article gives detailed instructions on replacing the convertible top locking motor (locks the folding top to the windshield) in a BMW E64 6 series vehicle. Even though we used a 2005 645ci to perform this repair, this article can be applied to any 2004-2010 6 series vehicle with minor modifications to the repair steps.
A BMW E64 convertible lock motor replacement is a common repair in 2004-2010 6 series vehicles.
The E63/E64 6 series was first introduced to the US market in 2004 and has been hailed by enthusiasts as one of the most iconic designed BMWs to ever be produced. The E64 version of the 6 series sports a fully automatic electrohydraulic convertible top that tucks neatly into the trunk when fully retracted.
Unfortunately the the E64 6 series convertible top has been plagued with operational issues, most notably those contained in SIB 012417 that led to a class action lawsuit settlement in November 2018 (please click here to view document). There have been numerous articles and forum discussions concerning the issues and remedies contained in SIB 012417 therefore we will not address them in this article.
One common problem that is not covered in the SIB but is well known among BMW E64 owners is a convertible lock motor failure that prevents the top from unlocking and separating from the windshield. The convertible top on the 6 series is secured to the windshield by two catch hooks which are retracted by an electric motor when the driver presses the top retraction button.
The BMW E64 convertible lock motor contains a plastic gear which turns two flexible drive shafts that retract or extend the catch hooks on either side of the windshield. Over time this plastic gear has a tendency to crack or strip, causing the lock motor to just spin without engaging the driveshafts when activated. If not replaced immediately it will eventually jam the electric motor, causing it to burn up. If you suspect the plastic gear in your convertible lock motor has broken DO NOT try and operate the top. You could cause permanent damage to an expensive motor that could be salvaged by just replacing the inexpensive gear.
There are some instances where the electric motor fails electrically. In this case the entire motor will need to be replaced. The good news is a BMW E64 convertible lock motor replacement is a very easy repair for the home mechanic and will avoid an excruciatingly expensive trip to the dealership or local repair shop. We give you full step by step instructions as well as a parts list below for your convenience.
1. Convertible latch motor gear (may be required) – Although it depends on what you find when you open up your broken latch motor, you most likely will need a new gear. The factory BMW E64 convertible latch motor was manufactured with a plastic gear that has almost a 100% failure rate as it ages. Only replace your gear with an upgraded metal one. The BMW Repair Guide only uses the following gear in their repairs.
2. Convertible latch motor (may be required) – If your issue is not the gear (or a blown fuse), then you most likely have a burned up motor. There is only one option when it comes to replacing a convertible latch motor…it is Genuine BMW. NEVER install a used convertible latch motor in your vehicle (from Ebay for example)…they are prone to failure and you are just wasting money.
This article assumes that the convertible top is stuck in the closed position on your 2004-2010 6 series vehicle and the latch motor will not unlock it. The good news is the BMW E64 convertible latch motor is easily accessible without having to manually release it. The plastic trim panel that conceals it inside the vehicle can be quickly disassembled by removing two screws.
- The BMW E64 convertible latch motor is located behind a plastic trim panel at the top of the windshield.
- Start by using a T10 torx bit to remove the two screws anchoring the side of the trim panel to the roof of vehicle.
- The trim panel is held in place with two metal clips. Grasp the panel on one side and pull down with steady pressure until the clip releases from the roof of the vehicle. Repeat on the other side of the trim panel. Remove the trim panel from the car.
- The latch release motor can now be accessed. Start by unplugging the two electrical connections on the motor as shown below.
- Using a 10mm socket wrench, remove the two nuts anchoring the motor to the roof of the vehicle. Pull the motor loose.
- Remove the two flexible drive shafts that open and close the side latches. They simply pull free from the motor.
- The motor can now be removed from the vehicle.
If you have diagnosed that your latch motor is operating correctly, then you most likely have a broken latch gear. As discussed earlier, the original latch gear is plastic and has almost a 100% failure rate in high use vehicles. The good news is the gear is easily replaced as shown below.
- The latch gear is located behind the black plastic cover on the top of the motor. Use a T10 torx bit to remove the six screws securing the cover to the motor.
- With the cover removed, the latch gear can now be accessed. Using your fingers, pull the convertible latch gear out of the motor.
- Using a high quality grease (we like to use marine grease), coat the worm gear inside the motor. Apply grease to the new replacement gear.
- Install the new gear and replace the plastic cover.
Reassembly is very simple…just follow the above steps in reverse. Make sure the flexible driveshafts turn freely and do not bind up after reinstalling the motor.