See Figure 1
Shift linkage adjustments are neither necessary nor possible on Volvo manual transmissions. The linkage is mounted internally and is permanently bathed in oil.
On 1970-71 140 series, the shift lever mounts directly in the top of the transmission. This configuration, although providing for more direct shifting action, required the use of a long wand-like shift lever with long throws required to change gears. This situation was remedied on 1972 and later 140 series cars, as well as all 164 and 1800 series and all later models, with the implementation of an inboard mounted, intermediate shifter rod. This rod allows the use of a much shorter, sportier shift lever and shorter throws between gears.
On these models the reverse gear detent clearance is the only adjustment that can be made to the shift linkage. When properly adjusted, first and second gears can be easily selected and the shift lever has about 1 / 2 inch of sideways free-play in either gear.
Remove the shift lever cover, the trim frame and if necessary, the ash tray assembly. Engage first gear and adjust the clearance between the detent plate and the gear shift lever. Also check the clearance with second gear engaged. Clearance should be 0.02-0.06 in. (0.5-1.5mm).