Hello gentlemen, I hope all is well.
As a background, I have a 2002 stage4 rex with 125k on the clock.
I seem to have developed an issue with 4th gear grinding. It's not a violent grind like when you mis-shift, it more of a subtle aggitation and only occurs when shifting into 4th gear fast at higher RPM's... for instance, when merging onto a highway I might be 3/4 throttle or more and going into a fast 3rd ---> 4th shift will initiate the grind. If I am driving normally no grind exists.
I am assuming this is the 4th gear syncro.
I am at 125k, treat my tranny well, and had the fluid changed to motul 3000 at around 70k so all should be good with this.
I know about all the synco mesh stuff and when a tranny gets older sometimes you need to just give it more time to engage as the syncros wear down. Howevever, I also know my clutch is starting to slip. Could it be that this is my clutch? I am on the stock clutch but determined to wear it out until there's nothing left.
This whole thing started about 2 months ago where for a couple days only EVERY single gear lightly grinded... even in normal drinding conditions. It was very strange and I thought my clutch was about to implode. Then, after a couple days all the grinding went away aside from the 4th gear grind under heavy throttle/fast shifts.