I have a 97 st. whenever I try to go to 4th it grinds, the only way to get 4th and 5th to stay in gear is to push in the clutch and slam it into gear really hard. If I rev match I can go into 5th without any trouble but then it just pops out after a bit. Is this a tranny or mount issue, or could it be the shifter bushings.
Grind on 4th and 5th - 6G Celicas Forums
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Try some Redline MT90. It cleared up my 3rd gear grind. It is a temporary fix but should buy you some time. Eventually you will need either a new tranny or a rebuild.
QUOTE (Niaaro @ Jun 18, 2018 - 4:03 PM) 
>I have a 97 st. whenever I try to go to 4th it grinds, the only way to get 4th and 5th to stay in gear is to push in the clutch and slam it into gear really hard. If I rev match I can go into 5th without any trouble but then it just pops out after a bit. Is this a tranny or mount issue, or could it be the shifter bushings.
Try some Redline MT90. It cleared up my 3rd gear grind. It is a temporary fix but should buy you some time. Eventually you will need either a new tranny or a rebuild.
My donor tranny had a 3rd gear grind according to PO, I put in Pennzoil SynchroMesh and have not had a problem in years, up or down.
'97 ST\ Eibach \ KYB \ Kenwood \ Alpine \ Cusco \ OEM+[sold 10/18]'93 MX-5LE