When I shift my automatic transmission in reverse after it has been parked for a long period of time (like over night or after work) it works fine. Wants I been driving and then shift in reverse it will slip, I really have to step on the gas peddle to get it moving, all forward gears seem to work OK. What could be the problem???
Automatic Transmission slipping in reverse on 2002 Volkswagen Jetta TDI
Really, you need to have your transmission looked at. it may just need a service, but the more you drive it this way, the more you could hurt it.
The transmission is well on it's well to failure, I lost my reverse for 6 months before I decided to replace the transmission after many adjustments and fluid changes. The line pressure boost modification was the most helpful but merely a temporary fix (2 weeks) then failure completely.
Its not a matter of if the tranny in your jetta will fail just when. What your experiencing is probably the failure of the reverse gear bearing with metal pieces plugging the filter leading to slippage. VW is aware of the problem but will not address it. I junked mine and bought a Focus!