Truck is a 1999 isuzu npr,motor : 4HE1-TC,Trans: auto_ AISIN SEIKI Ser. #9C0756,Mileage 130 K Transmission will not engage in drive or second,if you put in 1 st position truck will jump as it is supposed to do and pull off as it should,once it is going you can shift to drive and it works fine until you have to stop and then you have to shift back to 1 st position again to get it going again.  Truck will down shift from 3rd.  to 2nd when needed,and it will go in overdrive when it is supposed to .  no lights or indicators are showing.  Thanks for the help.

SOURCE: 2003 Dodge DSL 2500 transmission shifting problems

sounds like you should start by dropping the pan and changing the filter, put cheap fluid in it or reuse the old fluid if its not too bad bring it to a shop and have a transmission flush performed with a good flush machine your valve body is sticking and this should clear things up please rate -jeff

SOURCE: 98 Civic Auto Trans Slippage

you need to replace clutch pack for that gear can be ordered seperately from parts store or dealer if you want to save money call peach street auto recycling at 1800-365-2341 for a warrantied used one! also might be time for change trans filter and fluid filter could be slightly clogged but I lean towards clutch pack I replace these alot on Hondas

SOURCE: automatic transmission not shifting into 3rd or 4th

my 1999 f250 super duty will not shift into overdrive

SOURCE: 1997 Chevy 1500 P/U 4x4 small V8. Transmission shifting issue.

you may be confusing the torque converter clutch engagement with o.d. this trans has a problem with the T.C.C. regulator valve wearing out the valve body bore. this will cause the converter clutch to engage only sometimes or not at all. this will set a P1870 code in the control module. when this code is stored in the controller, ( check engine light may or may not be on), it increases the pressure in the transmission causing the 1-2 shift to be harsh. ask a local tranny shop to scan the vehicle ( most will do this for free) if this is the problem they can either fix your valve body (sonnax parts) or replace it with an upgraded valve body. hope this helps

SOURCE: 1999 sivlerado has no drive or overdrive

to start off change the prndl swich.