I just bought a 1992 240 DL automatic wagon last week and was very excited about it as it only has 97,000 miles and was meticulously maintained. But I am already having problems.

The xmission will not pop intp 4th gear, at least until the car has been driven for 15 or 20 minutes.
I took the car to an experienced Volvo mechanic today and he replaced the OD relay which I later found out was not the problem. I went back again as 4th gear was still not activating and the mechanic now claims it is either 1) a faulty solenoid or 2) the xmission.

I would like to try to replace the solenoid first myself but have heard it is a delicate operation as any dirt that gets into the tranny once the solenoid is removed could cause major problems.

1) Is it really difficult to R&R the solenoid?
2) Will the $150 solenoid (not the $250 Volvo brand) be good enough or can I get by with a $50 used solenoid?

Also, the rear engine/tranny seal was replaced 2 weeks ago (before I bought the car) but the dealer forgot to replace the PCV valve which was plugged and oil is leaking out again. A mechanic replaced the faulty valve today and the leakage has for the most part stopped.

3) Can the seal be permanenty damaged in that short of time (2 weeks) because of the oversight or should it be OK?

Thanks in advance for your comments.