Level 70 tanking survivability

[jibz]

So I've not played WotLK really until now, took a big break post TBC, rolled a death knight 2 weeks back, he is now lvl 70 and after breezing through TBC instances on I realised that things in northrend hit HARD.

After a failed attempt at tanking UK, I went ahead and bought the cobalt armour. However I still seem to be dying, is this a failure of my gear and spec just not been able to cope? Or are pally(off spec) / shammy heals just not able to keep a DK up in UK and should I only tank if we have an on spec druid or priest to keep me up (I think HoTs would definitely change the way things go)?

Additional Info:
Spec: Unholy
53% damage reduction pre buffs.
14% parry
18% dodge
10.5k HP buffed.

Missing tanking rings / trinkets still. Hopefull can hit def cap with these if I can find some (suggestions?).

Thanks in advance.

[Bulk]

I think you've just had bad healers to be honest - pre 80 instance should be tankable with out any special tank spec/stats - i.e you dont need to be crit immune (it helps, but afaik they are tuned so crits shouldn't instagib you). It also probably wouldn't hurt to pick up a few quest upgrades in northrend - some of the quest stuff is a fair bit better than outlands gear from only a few levels erlier.

[jibz]

Thanks Bulk, I'll give it another try tonight. The smithed cobalt pieces are pretty good, but I'll def replace them if I come across something better.