87 K5 with 379 diesel and th350. Reverse has been slipping for a while but everything else was fine. Then a month ago when I put it in drive, it would shift fine when the engine was cold and after 15mns or so it would only shift 1 and 2. If I put the lever in 2 and then in 3 it would shift to 3. evantually this does not work any more and now if I put it in 3 or 2, it remains in 1, if I then put it in 1, it shifts fine through all 3 gears !!!! except I cannot start in 1 as 1st slips when I start in 1, but doess not if I start in 2 or 3 !!! If this making any sense to anyone ? Can anyone help, I leave in Europe and parts are not easy to get. If I need parts could someone let me know exactly what I need to order to get it fixed. Thanks a lot.