Hyundai Aftermarket - 5th gear syncro grind

Hyundai Aftermarket (https://www.hyundaiaftermarket.org/forum/)

- Transmission, Clutches, Shifters (https://www.hyundaiaftermarket.org/forum/transmission-clutches-shifters-30/)

- - 5th gear syncro grind (https://www.hyundaiaftermarket.org/forum/transmission-clutches-shifters-30/5th-gear-syncro-grind-83614/)

5th gear syncro grind

Did anybody over the years ever disassemble their gears and syncros to find out what causes the common 5th gear syncro grind that a bunch of RD owners get after some time? Was it just bad engineering on Hyundai's part or was it found to be something else that causes it?

Doodoo syncro's or bad oil. I am NOT a fix from a can sort of person but - .. flush it with Redline MT-90 and see if that doesn't help

Flush a manual are you crazy?

From hyundai's TSB on the Genesis. Get a bunch of Redline MT-90 (they didnt say use Redline.. but anyway)

Drain trans

Put new fluid in - reuse old crush washers

drive for 100 miles or so.. shift a lot.. get the oil good and moved around.

drain

refill with fresh oil

install new crush washers with this one.

If that doesn't work its either time for a new trans or tearing what you have apart.