Well, I'm back at home now with my beloved Jeep and I'm pleased to say all did end up working out for the best. I must admit that in my darkest hour I was most pessimistic but to my great relief they ended up coming through for me and I have to say things ended up working out remarkably well. After thinking things over and discussing things here I did call them in the morning to say not to go ahead with replacing the solenoid and it was all back together ready to be driven off that afternoon.
I haven't mention it but the front tail-shaft was also making a horrible noise when in 4WD and I was pretty confident the universal joint or something would need replacing. I didn't mention it here as I didn't want to confuse the discussion too much but in the end they did end up replacing the universal joint and cleaning (but not replacing) the solenoid as well as adjusting my handbrake for me. As it was the bill came to $561, and covered the diff inspection/cleaning, replacing the universal joint and handbrake adjustment which is an amount I was happy to pay -in fact it was an amount I was pleasantly surprised to pay
. The day before they had estimated between $600 and $700 to replace the uni and reassemble the diff and I have to say this is the first time I have ever had a mechanic charge me
less than they estimated
The solenoid is once again working as it should but they say they have no idea how long it will last. Apparently the oil in the diff was pretty mucky and had a lot of mettle filings (and I think he even said gravel???) in there, so hopefully after having a bit of a clean and oil change the solenoid will continue to work for a while yet. If it does fail again I'll probably look at putting an entirely different diff in rather than replacing the solenoid anyhow.
So all in all I have to say it has worked out remarkably well, and despite my concerns in the middle it turns out I'm quite pleased with how it all finished up.