Third gear grinds after a few uses of it

[LowNismo17]

When i first drive my car down the road i can shift into third gear real smoothly for about 3 or 4 times in a row..but after about the 4th time it kinda grinds a lilttle..i guess u can say after everything heats up it grinds..also it grinds only 3rd gear when i get off the interstate after about 30 minutes of driving, but only grinds for a few minutes then stops.. right now i have regular tranny fluid in it..does anyone think some syncroshift will help the problem out any? any info would help

 

[Usual Suspect]

My 5th gear does the same type of thing.

Shifts fine the first few times, but seems that once things are warmed up it grinds a bit on upshift from 4th to 5th. Down shifts from 5th to 4th just fine. And all other gears are great up and down.

I have SyncroMesh in the tranny and have put new bushings in, and adjusted the cables (which "look" pretty new). None of that helped with the grinding in 5th although the car shifts a lot tighter now.

Its a weird problem, I figured it was just old age showing on the tranny, cables, or some adjustment I have not figured out yet.

Jon

 

[leet]

Probably a worn syncro.

 

[doodie]

My car was grinding 3rd too before I changed my tranny fluid with some penzoil synchromesh. Before the change, I had the same symptoms as you, smooth shift when the fluid is cold, but when it warms up it grinds. But everything quickly went away ~50miles after the fluid change.