Tryndamere, Singed, Darius, Mundo, Lee Sin.

I find Volidbear tends to roflstomp in TT. Is there any good way to counter him. His passive seems to be balanced for 5s and seems way to powerful is 3s

Volibear is fast, is tanky,has great damage, a fling (which is awesome), and that passive.
A simple counter which anyone can use is ignite, that will reduce the healing he gains from his passive by 50%, which is quite a lot. Wait for it to pop and blow ignite on him.

Volibear is extremely suceptable to kiting. Any kind of strong slow will shut him down pretty hard. A stun works great too (Wait for him to blow his speed boost and stun him)

Jax is a great counter per-se because when Volibear gets in his face, Volibear is stunned. Jax can also teleport away which is helpful.

Other than ignite and cc, there isn't really a 'great' way to counter him. Champions with greater mobility like Lee Sin, Jax, and Shaco can out maneuver him making him less of a threat.

How do you counter the other team turtling?

I saw you only talk about Udyr, Shyvana and Lee Sin
What other champs are viable to jungle on treeline?

Do you have any replays of your team playing on Treeline?

How do the mechanics of jungling for TT differ from that of SR? Doesn't the randomized spawns and map design hinder ganks?

If the other team is turtling, STOP KILLING THEIR INHIBITORS.

Unless we are about to destroy their base, we rarely destroyed the inhibitors.

KEY RULE: INHIBITORS = FREE FARM FOR OTHER TEAM

Keep Inhibitors alive and farm to your hearts content while they sit in their base getting no farm. They come out of their base? Ace and push.

Other champs that are viable to jungle on TT are:
Skarner
Mundo
Singed (I know it's crazy, he's just so broken you can put him wherever)
Shaco (kinda, he's not very good anymore)

Twisted Treeline is incredibly difficult to jungle in, as such only the best junglers can handle it.

Yes, I have replays of Zacynthos, Morojax, and I playing on the Twisted Treeline versus other top teams like 1300pro, Just Tryhard, and such. Although my dilema is either I post a video of our team getting stomped on, or our team stomping on another team. Either way I feel bad about it.

If you really want a video I have one in mind of my team vs. HaoZ - EvilLust - Sarrano
If you want to see it add me in game and I can link it to you (It's on LoLReplays).

No hard feelings though if I remove you afterwards though okay? I have 299 friends and I'm keeping a slot open for Riot Taco Storm

Mobs hurt. A lot more than in SR. On top of that, as you pointed out, because they are random you are often just rolling the dice. The ideal thing to get is Golem camp mid, and then wolves top. But ofcourse there is a low chance of that happening.
Since the map is so small and crunched, jungles can gank much faster and you'll see ganking happening a whole lot more.

To be perfectly honest,I think the most important role in Twisted Treeline is jungle (I played Bruiser top).

If you are fast, good at csing, tanky enough to withstand the teamfight, and most importantly good at ganking, you can carry most any team. Although few people can truly do this. Tiberius Steele and Morojax were the only two players I ever saw that could constantly play jungle perfectly in TT. The balance of speed, tankiness, damage, CC, mobility, and ganks is incredibly hard to get right.

when I play singed i bind /l to my T key and spam it to initiate team fights..

i also rush boots/philo stone/move 3 boots/ ROA/Rylais

am i doing it right?

Should some how ask BabeeQ :P

Yea BabeeQ would know it better than me. Although I think my answer was sufficient
Seriously though, you want to be 2500 Riven, talk to BabeeQ.