Engine Mount and Drive Installation

January 2005

The Problem

On the New Beetle, there are three engine mounts:

• Two mounts on either side, suspending the engine. One on the transmission, one on the engine.
• One underneath which is a steady bar, which prevents the engine from twisting in it mounts. This is attached to the transmission.

Since we are still going to use the transmission, we will keep the transmission mount and the underneath steady bar. However, since the engine has been replaced with an electric drive, a new mount for the drive side must be designed.

Aligning the Drive and Transmission

Aligning the drive and transmission is not absolutely critical as the CV joints can accommodate for some misalignment. However, the closer to perfect alignment the smoother the engine will operate, and the less wear on tear on the drive train components.

What is perfect alignment? Since the transmission is already held in place by an engine mount, we only have to align the other side of the engine. What is this alignment? Imagine a line from the center of each front wheel. Imagine another line along the axis of the motor shaft. These two lines need to be exactly parallel.
 

In the actual installation, it was difficult to align to the center of the wheel. Instead a rigid cross member was bolted to the sway bar mounting bolts on the lower travelling arm of each wheel. This bar was very accurately installed to ensure a precise reference point.

Since the transmission side is bolted using the stock engine mounts, the center of the transmission shaft (first picture below) was measured against the reference bar.

The measurement was made with a square with a level attached. The square was placed against the reference bar, aligned to the center of the transmission, the adjusted to ensure it was level.
 

Then the other side of the drive/transmission, the drive side, was moved into position, using the same measurements as measured against the reference bar. The drive/transmission is now in proper position.
 

The Engine Mount

The mount on the VW New Beetle is a cast aluminum shape which mates to a specialized rubber mount on the frame of the car.

Here is the old engine mount bracket, the actual mount on the frame and the drive back.
 

The intention is to cut off the mating portion of the engine mount, and weld an aluminum plate which is machined to fit the motor. Here is the general concept:

In the actual installation, it was much simpler to fabricate a mount out of steel. Once the engine was in its proper position, a mount was fabricated to keep the engine in this position.
 

And pictures of its installation:
 

Drive Installation

Drive Installation was very anticlimactic. The drive was bolted to the transmission, the new engine mount was bolted to the drive, the drive raised into position and bolted into place.