Yes, the H2A tranny is quite stout. As well as the earlier H2AV in the 93-97. But in reality any thing can mess up. Yes, I have replaced a H2AV in an
80 series that has gear lube so thin, and black it was more than likely original(ask Romer). They typically do need front and rear bearing replaced along with the seals if one buys a stocker and then adds a higher lift after a 100k miles(bearings start whines due to the bearing not riding in the
same groove. Seals do leak. I just replace a H2A in a 2006 that was clunking so bad, it might of needed a center diff(Setting on the floor at the shop, customer did not want me to tear into it to find the issue. The customer opted for a new one which I supplied for him. His major clunk is gone now(he still had drive train slop, but not the real bad clunk he had). I have rebuilt a few of these for customers over the years, as they do wear and have more back lash or even the input gear moving back and forth.
Again, while these are a stout t-case, they do not last for ever, nor are they as stout as some Believe. Case in point, some guy on mud
trying to jerk a guy out stuck to the doors in mud, broke his t-case, not his diffs or drive lines, but his diff pulling in the right direction but used the wrong pull strap(really should of used a tug or Bubba rope) or really needed to use a winch. Or some other method than he did use which hurt his cruiser.
I am writing not to generate work, but to provide in site into this t-case and how one can mess it up.
Lack of Maintaince at the proper intervals(I would suggest no more than 30k miles on conventional gear lube, 0r 50-50K miles on synthetic gear lube). Do not use improper equipment to pull stuck vehicles out(more damage to cruiser are done helping others).
Have the t-case checked for wear at milage over 150k. Anyhow, there are rebuild kit available for these t-case today, so it cuts the cost of
all the bearing and seals to a reasonable cost any more, instead of buying all the bearings and seals from Toyota. I would suggest anything over 200k is going to need some adjustments or a rebuild. Wear does happen. All this is just my Opinion, but some of this is based on 22 year of Landcruiser works as well.
The center differential is small compared to the front diff, and has even really small spiders in side, this can not take the abuse like the earlier
split cases where gear to gear contact is. The center while nice, is weak. Be nice to your Cruisers. The rest of the case is strong, but again the center diff is small and has very small took contact. Bearing are big, and the input gear and idler gears are big and beefy. Contact is good, but this depends on the shims that move the tapered bearing, to support the idler properly.
Anyhow, I am not looking for work, I have way to much in front of me at the shop. As for other shops that will work or can work. Contact them