I have an 01 with the 4.6 and the 5 spd. If I drive the truck for two to three hours on the highway when I downshift into third it grinds unless I push in the clutch and wait a few seconds for stuff to slow down. This has been going on for about nine months and now fourth gear has started doing the samething. I think it is the syncros but am not sure. Any help would be
appreciated. thank you.

 

Those syncros are going bad. Time to have it rebuilt.

JMC

 

Rebuild or take up double clutching.

Adrianspeeder