1997 golf diesel manual transmission is getting

Hi are there any fault codes?

check and replace the TCM

These type's of symptom indicates a failed transmission in a GM car.

code p 1870 refers to transmission component slipping
the transmission may need clutch and band adjustment or a pump pressure test check as it may not be producing enough pressure to keep components in place

check and adjust the linkage...
Best regards
Ck

The absence of 3rd and 4th is imposed by the transmission computer as a precautionary measure. The system has detected fault and rather than risk doing any greater damage has provided a limp home service. It needs to have a transmission specialist look it over and read the error codes. How do your transmission fluid levels look?

check fluid, if low try again, if not rebuild time

This is a fault mode in which the transmission either loses electrical power or the PCM deactivates all of the electronics. The transmission will default to max line pressure. The driver will have Reverse and 3rd, with manual 2nd available by putting the gearshift in 2 or 1 (doesn't matter). 1st, 4th, and TCC lockup will not be available. It will not hurt the car to drive it like this for short periods, but use manual 2nd to get the car moving, and be aware that the trans will generate more heat than normal while operating in limp-home mode due to increased torque converter slippage during 2nd gear starts and no lockup in 3rd gear.

Trans shifts into gear harshly, car feels sluggish off the line, No 1st, 4th or TCC lockup available, Manual 2nd, 3rd and Reverse are only available gears, CEL is on: Transmission is either in limp-home mode or has lost electrical power. If there are lots of error codes in the PCM, check the under hood fuse that powers the transmission, and if it pops again, look for a short in that circuit like an O2 sensor harness touching exhaust. Otherwise, check PCM codes for a particular fault in the transmission causing the PCM to put it in limp-home mode.

No 1st or 4th available; trans shifts 2nd to 3rd by itself in D or OD and locks the converter : ShiftA solenoid failed. Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

Car goes into gear but feels very sluggish like the brakes are dragging, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

Need to pull codes 1st, the electronics of the transmission can cease all proper operation of the transmission. Have the DTC's checked before proceeding.

look inside engine compartment, locate the transmission has metal linkage arms with plastic round end connection in to metal half ball mechanism , play with system, move it back and forward, side to side, they are behind transmission and left side of car standing on front, by playing You will notice free play in one, that's the bad one, look in to getting all new