I thought I might add to this thread as I've started getting intermittent symptoms like the OP over the last few months. Only last week did I start getting the infamous code 62 fault come up. I took the plunge and ordered a set of solenoids from eBay as mentioned in another thread.
http://www.ebay.com.au/itm/UPDATED-DESI ... _830wt_689
Anyway, today they arrived from the states after about a week and I changed them out straight away after work. The new solenoids are much smaller but everything fits perfectly. Took me about 2 hours to change them in my driveway. I didn't remove the turbo dump pipe which runs all the ways under the transmission pan which was a pain though. I simply dropped the pan onto the exhaust which gave about 50mm of clearance. I had to first drop the front prop shaft off the front diff though, leaving the rear of the prop shaft connected, to allow me access to the gearbox pan bolts along the right side. It was a tight squeeze getting my fingers in to the small 50mm gap but I got all three solenoids replaced with no real dramas. Two of the solenoids are accessed from the left side and the third solenoid from left rear of the tranny.
All up, cost me just over 200 bucks including 4litres of ATF and some new sealant for the pan. Took my surf for test drive and everything seem okay so far. Gear changes are spot-on and the torque converter lockup was working as it should at around 80km/h. This is for a KZN130 surf too but can only assume that he solenoids are identical in the LN130 surfs.
Hope that helps.