2001 Nissan Pathfinder Question: Transmission Service

I had the transmission fluid changed in a Toyota Cressida with over 200,000 miles. The transmission was working perfectly when I drove it in to the shop. A different story as I was driving away. The transmission would not upshift unless you brought the engine rpm's very high, then it would go into the next higher gear with too much force, lurching forward. Went back to the shop and they said that the new transmission fluid had dislodged some dirt or had cleaned some old seals which now allowed fluid to pass by the seals inside the transmission and it would take $3000.00 to fix the problem. I took it to a mechanic friend of mine and he made a simple minor adjustment which took less than 30 seconds and the transmission worked perfectly for another 100,000 miles when I sold the car. Was the shop which changed the transmission fluid dishonest and making adjustments to the transmission to drum up extra business? No way short of waterboarding to ever know for sure.

I now have two 2001 Nissan Pathfinder 4X4's, one with 137,000 miles and one with 175,000 miles. I had the transmission fluid changed out by Advanced Auto who uses a method whereby they introduce new fluid into the system while taking the old fluid out. It is a simple process done by disconnecting the transmission fluid line that goes into the transmission fluid cooling radiator and pumping new fluid into the radiator which returns to the transmission while draining out the old fluid as it arrives from the transmission. This, of course is done while the engine is running. Using this method, all fluid gets replaced. I had this done last summer and have not experienced any transmission problems.

what was this "minor adjustment"?