Rb25Det Box Sometimes Doesnt Go Into 3Rd

[boostn0199]

At my last drift day i noticed a new problem with my box. Basically on one corner where I take a hairpin in 2nd and hold it at limiter for a while then quickly have to shift to 3rd sometimes it would not go in.

At all other times its fine and goes in easy, clutch kicking in third and 4th no problem but just that one particular situation when I have to hard shift from riding limiter in 2nd to third sometimes is no go. Anyone got any suggestions as to what is actually worn or about to wear out in the box? Syncros, or is third gear about to completely go?

Some more info is its a HHHDB exedy clutch running redline shockproof oil, slave and master are new aswell.

[GTSBoy]

Got to be a synchro issue. Try going somewhere dark and quiet and do it in a straight line. Hold second for the same length of time and see what happens. Make sure the oil is as close to warmed up the same beforehand too.

[Moodles2]

Check trans fluid level, depending on the batch of shockproof, it's been known to climb out of the breathers

[boostn0199]

Yeah I tried it straight line and its fine only on that corner. Im thinking might be worn gearbox mount and under cornering its moving around.

Ill check fluid levels aswell.

[Dose Pipe Sutututu]

Similar thing happened to me with my old R33, I just took a stab and filled it with oil till it dribbled out from the side and guess what? no more issue!

Worth a try right? No harm.

[boostn0199]

Yeah Im going to change the mounts on the weekend and going to drop the oil to check if any metal syncro clips are in it then refill it up.

[Humbla]

Cant find 3rd go for 4th thats what i do,

these boxes are really old now so you have to put up with em.

Mines been a bit how ya goin for ten years but she still works.