My daughter's pathfinder would not shift into second gear until the engine was completely warmed up. I had no OBD II codes. I searched the Internet for an easy solution. I read that It's "OK" when it's cold outside for a transmission to take up to 3 miles or 3 minutes to shift into second gear . They give several BS reasons why, and then state it's "normal". BS! If it takes 30 seconds to minute to shift into second, there is a problem! I believed the crap about hardened seal's, etc. I put in trans max, Lucas, etc, they didn't work. As recommended by the internet pro's...I replaced the solenoid pack As recommended by internet pro's, even without a OBDII code That was my issue, I had no codes...it didn't work. I replaced the O'rings on the shift accumulator pistons, As recommended by SEVERAL internet pro's. it didn't fix my problem. Today, I took a entire valve body from a 04 Xterra 2WD transmission from Pick N Pull, ($50.00) installed in the 1998 pathfinder transmission, and the Transmission shift's like new again.
SOO, if your RE4R01A Transmission has an issue, the gut's from my 98 to an 04 are "nearly" the same. By that I mean the Valve Body with solenoid's.
A TRICK HERE: When you drop the valve body, 3 springs will fall out that are located between the transmission case and the valve body on the driver's side of the transmission They are shift piston/accumulator springs. NO PROBLEM! Look up on the internet for the drawing of which bolts need to be removed. There are two different length's of bolts, make sure each bolt goes into it's proper hole.. When re-installing the valve body, just barely start a bolt on the passenger side of the valve body. This will allow the drivers side of the valve body to hang down several inches. This allows you to install the springs, then lift the valve body up to the transmission and install the rest of the fasteners. I wish I could have found that information on the internet.!
I was quoted $2900.00 to repair this transmission from a independent transmission repair shop, NOT including a defective valve body! I was told that would be extra. Yep, "PRICES's" transmission shop in Virginia Beach, VA quoted me that last week.