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Assembly of Synchro Gears

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INSTALLATION DISCLAIMER

*Gears are not designed for drag race use only, manufactured for affordable costs and average street car/roll racing/weekend warrior customers in mind**

Improper use or abuse over hp rating can result in breakage, although some have done it and it works it is not suggested for reliability and long term use**

**Professional assembly is highly required**

Professional installer needs to have, window casing, various shim sizes and input shaft thrust tooling with dial to set endplay correctly**

Gears are bigger sizes than oem, clearances will be much closer between gears. Should not be installed blindly and must pay close attention unlike oem.

If do it your self have all the tools or borrow. But you assume all risk and liability if not done correctly.

Modification Required To Clearance Bigger Gears

Must clearance reverse actuator and fork to give space between bigger gears.

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.

Clearance between 1st slider in gear 1 position when countershaft bearing correctly shimmed and clipped to top casing.

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 gears

0.006-0.008"

Suggested endplay for dog gear

0.008-0.010"

Or follow what you builder recommend also.

Link to thurust 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

Dial and magnet base pictures below

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CONTACT

If any questions please contact us in email sales@fftransmissions.com