Subaru Outback Issues

I have a 1998 Subaru Legacy Outback (automatic) that has 176,779miles on it. I live in San Francisco and only drive the car occasionally every 2-3 weekends out of the city. Recently within the past month I have noticed that after turning on my car and once it is in drive for the first 10-15 minutes it has a hard time getting past 20 mph. When I put the foot on the accelerator to go past 20mph the rpm goes way up to 4, 5 or 6. Once it gets past this then car is smooth and I have no problems. This problem seems to go away within 10-15 minutes of driving or if I turn my car off and then on again it seems to go away. I called my mechanic and they said it could be that the transmission fluid is low. I checked the level and it is perfectly normal. Any ideas?

Ask you mechanic to check if there’s a problem with the transmission slipping. I had a similar problem with an auto transmisison on my Ford truck, and the only way to fix it was to have the xmission rebuilt. A good mechanic can determine if this is a transmission problem or not.

If the transmission fluid level is ok then there may be a valve in the tranny that is sticking. A lot of folks have used a product called Trans-X in the tranny to fix the problem with good success.