Adjusting the 5th Detent Bolt

If your trans has one of the big white plastic capped detent bolts found on the older trans, that is the adjustable 5th gear catch. It is used to adjust the force needed to move the shifter in the car to the far right to line up to select 5th gear.

This is a pic of the parts of the detent, and the order of assembly. The rod is inserted into the hollow threaded pipe in the direction shown, and the spring and brass spacer slide over the rod. The big plastic cap holds the big spring, and the metal cap nut, which threads onto the hollow pipe and controls how much compression the small stiff spring gets, and as a result, how hard it is to push the rod with the rounded end up into the hollow pipe.

Lightly lubricate the parts prior to assembly to prevent corrosion...

This is a view looking down into the hole where the detent goes, and you can see the tab of the selector mechanism inside which the rounded end of the rod contacts.

As the selector is pulled out, on the way towards 5th gear selection, you can see the selector has a raised portion, and it is this raised up portion which will shove the rod in the detent bolt up, compressing the small stiff spring. You can insert the detent bolt too far, and it won't allow you to get 5th gear. Too loose and the rounded end of the rod won't catch the selector tab or raised portion.

Assemble the selector bolt as shown, adjusting it so the rod is about flush with the top of the cap nut, and running the lock nut all the way up the bolt. Don't forget to use a sealing washer.

With the trans out of gear, thread in the detent, and watch the rod in the middle. As you thread the bolt into the trans, the rounded end of the rod will hit the tab on the selector. You'll see the rod start to lift, and you'll feel the small stiff spring start to compress. Back the bolt out 1/3 of a turn, and spin the lock nut down, so you tighten the detent bolt into the trans. The rounded end of the rod should now be just hovering over the tab of the selector inside. If you pull the selector out as if engaging 5th gear, you will see the rod in the middle raise up as it rides up onto the raised portion of the selector inside.

To adjust, you lift the large plastic cap up, and this will compress the big weak spring, and allow you to turn the cap nut without turning the threaded pipe portion of the detent bolt, so the previous procedure won't be affected. When you have the plastic portion lifted, spin it to adjust.

This picture shows the cap nut nearly unscrewed from the threaded pipe, the small stiff spring inside is less preloaded, so it is the weak setting.

This pic shows the cap nut threaded as far down as you can go, giving maximum preload on the stiff spring inside, making this the strong setting, and requiring the most force to get the shifter in the car moved to the right.

Replace the protective plastic cover and you're all done!

 VW, being VW, have a specific starting spec for this force, and then it is adjusted to suit the driver, but sure enough, they give a base figure specification for it. You use a spring gauge, and attach it to the selector, and it should take 22 pounds to overcome the catch. At the gear lever in the car, it should take a minimum of 9 pounds, measured below the gear lever knob.