w124-250td, sticking in 2nd gear, help
 

its a manual box, and it started to stick in 2nd.
i jacked it up and saw one of the grommets was missing from the selector rods, so i replaced them all and it was ok for a few miles. but now its sticking everytime i go into second. if i bang the gear lever hard to the left it frees it.
any help would be welcome thanks.