hi my 86 tdi 110 has been running great but last week just got a mile from house and couldnt get 3rd and 4th gear and very hard to push into 1st and 2nd, its the same if engine running or not so not clutch issue! oil level is good\! have took the top of box off and nothing looks out of place [for all i know!] any body any ideas on what the problem could be? was supposed to have been a recon box 12 month ago and gears have always been easy to find and smooth! thanks in advance!