Must clearance reverse actuator and fork to give space between bigger gears.
HELPFUL TIPS
Shim on countershaft
The shimming here affects how much the whole countershaft stack will raise up when it clips in to bearing of top case. If shim is too tall than the stack will not raise up enough and can cause clearance issue in cirled area.Once you have the right shim installed measured in case, close it and bolt some bolts, clip in the countetshaft and inspect in the window case hole to make sure slider in 1st gear and 2nd gear has engagement on teeth. Notice that slider does not need to touch bottom of gear, engagement teeth are space up from gear. Check make sure slider has clearance on mainshaft of 1st gear between bottom of slider and top of mainshaft 1st gear. Do this with forks installed and using detent ball, spring, bolt and washer as the fork will locate the slider in position. If need adjust shimming to move stack up or down.This can only be checked with top case bolted on and bearing clipped or a window casing, a used bad case with holes cut open to see inside fully assembled gearset.Please use new countershaft snap in bearing, as old worn units can be very badly worn and have very much play in the ball bearings and move inside the bearing casing.1st slider will always touch and rest on top of 1st gear mainshaft when it sitting and not clipped in to top of case and raised up. As picture shows.Checking full assembly in window case is best option to see everything work and fit proper and all gears engage fully.
Tool
INPUT SHAFT ENDPLAY
Input shaft normally uses one flat shim and one conical spring under 1st gear and endplay is set with top shim above bearing in top half of casing. You must use custom thrust tool and dial gauge with magnetic base. There are kits available and we have added links below.You can also google and find videos how to do this procedure.In short, you install mainshaft stack fully assembled in case alone with your shim and bolt top casing down and made sure the shaft can spin. If it does not spin use thinner shim at top.If it spin ok than you can use that shim for setting endplay. Once everything is installed and completed, you can an install your original top case with shim, bolt top casing down and install thrust tool kit on mainshaft at clutch housing side.Push the shaft or lightly tap it toward top case, than use adjustment screw on the base of thrust tool kit to pull shaft toward you against dial gauge and it will read how much thrust play is there. Make sure dial is set to zero before.Adjust from there with thinner or thicker shims to get desired play set. Just repeat process.Suggested endplay for synchro gears0.006-0.008"Suggested endplay for dog gear0.008-0.010"Or follow what you builder recommend also. Link to thrust tool kit https://1320performance.com/products/1320-performance-transmission-mainshaft-thrust-tool-set-for-d-b-k-j-manual-trans-replaces-oem-honda-part-07gaj-pg20110-07gaj-pg20130-07979-pj40001?srsltid=AfmBOorjwfk4Xk02RNbQUJ2HX4PkgL4nm3QMYRhiDS001quMv-7CiASn
Window case example photo for easy assembly for checking clearances, alingment and gear engagement.
Magnetic base and dial gauge for thrust endplay set.
