grinding into 4th

[speedjunkie]

somtimes wen i shift into 4th gear it grinds and also somtimes i hear this wierd screaching noise coming from my transmission i think i jus shake the shifter around and it goes away could n e body help me with a diagnoses thanks

[96maxse]

someone answer this, I need to know too.

[evildky]

are you clutched all the way to the floor? are you shoving it in quickly or sliding it in slowly, it could be a worn syncro

[nsrZ32]

Mine used to grind going into 4th from time to time when I got the car like 6 years ago. I drained the transmission and filled it up with Redline Synthetic MT90. Sounds gone and the transmission has been perfect since. Happens with a lot of Z's and that fluid always fixes it.

[Booztd 3]

Happens with a lot of Z's and that fluid always fixes it.

I would say this is quite far from the truth. In some cases switching out to a better quality fluid 'fixes' the problem, but in reality its more of a band-aid. The problem with our transmissions is the insert springs like to wear out. The function of these insert sprints is to butt-up against the synchro to get it up to speed for the next gear transition. Whenever these springs are shot, the synchros arent allowed to get up to speed for the next gear, and thats why you get your grind. The synchro isnt the problem.

[nsrZ32]

I realize it isnt a permanent fix but I know quite a few Z32 owners who have gotten over 50K miles of problem free operation after swapping out to a better quality fluid. Unless you've got the coin to rebuild it, that's the sensible "fix" 9 times out of 10.

[Hybridpunk420]

i had the same issue on my 93 NA 300ZX... and like evil said, i think its a clutch issue... i swapped my stock clutch out for an ACT hdr6 clutch and flushed my fluid... no more grinding or weird noises