3-Link
Resources:
- Assembly manual: ’65 Roadster Mk IV
- Factory Five Koni Rear Coil-Over Shock assembly instructions
- Koni Series 30 1720 adjustment instructions
- 3-link instructions by forum member Hozr
The solid axle was purchased from Moser Engineering. It has has 3.55 gearing and is ’Traction Loc’ (limited slip differential).
The axle housing is connected to the frame by four attachment ‘points’; this is the 3-link configuration. The attachment points are as follows:
1. Via the shocks, which attach to the axle housing at the panhard axle mount and traction lock brackets. Note that the shock is mounted in the ‘body down’ position:
2. Via the shorter panhard bar (‘upper link’) that is attached on one end to the ‘banana bracket’ and the other end to the frame.
3. The longer panhard bar that is attached to the panhard axle mount bracket, on the PS of the axle housing, on one end, and the frame at an attachment point just above the traction lock bracket on the DS. Note: this photo is from my earlier build that used a different differential cover.
4. Through the lower control arms that span the axle housing and frame.
The most ‘dramatic’ part of the rear end build was getting the rear axle and housing into position through attaching with the upper link, the lower traction arms and the shocks. It took about 1 hour with the help of friends to move the axle housing into position using a floor jack, some raw lifting and final positioning of jack stands. Once that was completed I did the final attachment of the shocks, spacers in the lower control arms and Panhard bar without needing any additional help.
The shocks were attached body down (i.e., springs up). When in the spring-down position, the spring is within 1/8” of contacting the traction control bracket. There is quire a bit of discussion on the forums about the shock position, and the build manual and build video show both orientations. Koni states that the Model 30 shock can be mounted in either position so I mounted it spring up to avoid the potential for the springs hitting the traction control bracket.
The biggest time effort was getting the spacers correct for the different attachments. The lower control arms fit perfectly into the frame brackets but had a gap of 1/8” when in the traction lock brackets. So, some spacers were added. The upper shock mount fit perfectly with the 1.09” spacers but the bottom fit had about a 1/4” gap which was made up using spacers.
The largest puzzle was getting the Panhard bar frame to fit snugly against the 4” round tube. When the chassis came from the factory there was about a 1/3” gap between the frame arm and the round tube. I drilled the appropriate hole in the tube but was unable to ‘pull in’ the frame with a bolt.
The problem was solved by loosening the DS rear bolt attaching the Panhard fram to the chassis, drawing the frame to the round tube using the bolt and then elongating the hold with the absent bolt using a drill. Once done, the frame was firmly attached and the bolts torqued.
