Manual Shifter Linkage Adjustment

 

Manual Shifter Linkage Adjustment

 

 

If you’re having manual transmission shifting problems and the clutch is properly adjusted, it may just need an adjustment of the shifter linkage. This applies to both stock GM and aftermarket Hurst 3 and 4 speed shifters. A check can be made to see if an adjustment is required. To check, shift the trans into neutral. There is an alignment hole in each of the shift levers on the shifter just above the shift rod pivots. On column shifters these are located on the steering column under the hood. Insert the proper size gauge through the holes in all 3 (2 on 3 speed trans) shifter levers. You can use the proper size drill bit or if necessary, fabricate one out of round rod stock available at hardware stores. Sometimes limited space requires bending a tight 90 degree angle with about a 1 1/2” straight section on each leg. On Hurst shifters the proper diameter is ¼”. On some stock shifters it’s 3/16”. It must be just a few thousandths smaller than the holes in the levers. The gauge must go through all holes simultaneously without binding or interference. If it won’t go through all the levers or it binds, a shift rod adjustment is necessary.


To make this adjustment, loosen the locknuts on the shift rod pivots (stock shifter) or remove the clips and pull the pivots out of the levers (Hurst). With the trans and shifter in neutral, insert the gauge through the holes in all shifter levers and leave in place. Now adjust the pivots as required so they will go into the pivot holes in the shifter levers, then tighten the locknuts or reinstall the clips. On Hurst shifters this will entail turning the pivots on the threaded rods to move them. Remove the gauge from the levers and shift through all gears. Shift into neutral again and insert the gauge. It should slip through all levers. Now is a good time to tighten the trans shift lever retaining nuts or bolts at the trans side cover.
On Hurst shifters with stop bolts, here’s the method of adjustment on those. Loosen the locknuts and back off the stop bolts until just a few threads remain engaged. Shift the shifter firmly into third gear, then tighten the rear stop bolt until light contact is made with the shifter lever. Back off the bolt one full turn and tighten the locknut. Now shift the shifter firmly into fourth gear and adjust the front stop bolt the same way. Remember the Hurst ads from the 60’s that said, "Shift as hard as you want but don’t break your arm”?