After wiping more on Gruul last night, Im wondering if we are doing something wrong with healing. Our healers are currently just using there largest heals to keep me up, but i find large heal gaps, and if i dont dodge or parry in that gap i die. this has lead to many 10-20% wipes as i can do nothing but watch my HP drop in 7k lumps.

Any suggestions?

Have healers stand on rocks in range of MT without assigned movement patterns on Shatter, meaning they just stand there the whole fight unless someone blasts them dead or they get a cave in. Also make sure people don't get too close to healers unless absolutely necessary, as it always doubles the chance to get a cave in on one.

It is also worth stacking HoT's for this as well, but apart from that rocks and people staying away from healers to lessen chance of cave in is pretty much what needs to be done, I can understand the difficulty of being a main tank and wondering what is going on as usually what you are fighting blocks the view of the rest of the raid

haha yeah, the veiw of a tank is 2 big legs, or maybe a dragon head, but thats about it :P

most of the deaths havent been during a shatter stage, i just seems to die, seems gruul can time crushings in the 0.0001 sec my Sheild Block isnt on bring back old style imp sheild block imo.

19500 HP, 26% dodge 16% parry iirc, so thats not the issue, but i kinda just die. what heals should diff classes use?

They should be able to heal and cancel if your 100% safe, as a paladin chain casting 70% of the time should be viable even in blues - the fight really isnt mana intensive.
Make sure they arent reactively healing, thats bad in prety much all tbc fights.

I assign 2 healers on the OT, everyone else on the MT.

Usually I use GHeal 2 (2500ish heal) when I have alot of other healers assigned to one target.

Near the end of Gruul I would hope that your healers would be spamming a higher rank (maybe even max) nonstop, cancelling only if the tank is full if cancelling at all, incase a big hit comes. When a Reverb is about to hit they need to make sure you are topped and you need to have your Shieldwall hotkey ready just incase. Sometimes a wall at 20% (somewhat earlier than you would expect to use it) will guarantee a kill. Usually those 'oh shit' moments wake healers up.

Are you having paladins use Imp LoH for a 30% armor boost for the last 4 minutes (last half, roughly) of the fight? Get two paladins to use this then pop a mana pot.

No, I'd say you want to save SW for late, but definitely use your other timers. Try to have at least two healthstones (3 ideally!) so you can save yourself on reverbs. Also of course Gem and Last Stand. LoH at 11 growths or so if you're going well.

As for healing, I've done both jobs -- healing the OT is pretty easy, since it's so predictable. I'd queue a max rank heal for him, he gets hit, it lands. I either pause and regen a tick or top someone else off or toss a heal at the MT, then queue a new heal, cancel if the OT dodges the HS, and otherwise it lands. Repeat.

Healing the MT is trickier, but really it's hardly anything your healers shouldn't have experience with if they've done Nightbane, Maulgar, etc. For the first half of the fight, healing should be pretty relaxed unless you have way too few healers. Keep Earth Shield on the MT at all times and try to get everyone with HoTs to keep them up as much as possible if they can, to smooth out spikes and crucially to help handle bad Reverbs.

As a healer though, mana management is key for me. I'll pot up and use mana pots to keep myself more or less at 90%+ mana without having blown Mana Tide, until 11-12 Growths or so. At that point I'll switch to spam mode, using my remaining mana timers to sustain myself, hopefully until he's dead. Make sure your healers are spread out, because if you have 3 of your 4-5 MT healers moving out of a Cave In at the same time, something very bad is going to happen.

Crucially, combat log every attempt. If you die late in the fight, look back and see what happened -- did you miss a shield block and take a 14k crushing? Did you somehow not get any heals for 5 seconds and die to 8k, 8k, 8k over that time? If so, who was supposed to be healing you. Why weren't they? Were they OOM, OOR, repositioning, asleep, etc?

any good combat log parsers? the spam is a little bit of a pain to read thru, but not impossable, we also use WWS to look at damage etc but wont help with my damage and in the order i get it.

Also i have Juju of escape, 3 HS, 2500 armour pots, last stand, but i keep my pocket watch in over the Gem. I know none where OOM, as we can usually get another 5-6% down with the OT tanking.

Crushing is a problem some times as i get it as soon the sheild block aura is down and im spamming sheild block for next one, maybe client lag?

Mana issues should never really be a problem for healers. Are you dying when you have to reposition Gruul? During silences? Are healers dying from shatters? Keeping thunderclap up and spamming shield block each time its up helps out the healers considerably. Constantly ticking hots have always served as a nice buffer and if you have someone spamming flash of lights on the tank, it will allow time for the larger heals to land.

If all of your healers are all healing reactively rather than pro-actively, that could be leading to your death as well.