Hello, all!

I have 2005, L322 td6 with GM5LE40. and the endless story.

When I accelerated there was no problem, when there was a load change (stop the vehicle and start, the drive is loose. Little backlash in the drivetrain) Ok, I changed the oil (first mistake I think) some "75w90 API gl4 + full syntethic" certification I flushed front diff, rear diff, and transfer case with this type of oil, because I know, I need to replace the transfer case soon as possible. Little better, and after 3000km, the car can't turn :'D When I turn 90 degree, the car started to slow down, i hit the gas then a clicking sound. I thought the transfer case chain came loose and jumped.

I lifted the car, to watch maybe front or rear diff problem, which is not differeal maybe, and it stretches the drive train, when the RR it's on 4 wheels.I checked, but front and rear diff work well, the transfer case can't differeal. Tomorrow I disassembly, and watch, how much, the real property damage.

Question is:

Question 1.: Wich type of oil same as this one: Castrol BOT 26 FMB 1 STC4861

Option 1. : Castrol SAF-XO 75w90
Option 2. : Same but newest name: Castrol Transmax Axle Longlife 75w90
Option 3. : MOTUL GEAR 300 LS STC4861

Question 2.: Maybe, somebody know wich parts need to replace the "bad" trasfer case, to I hold on the shelf the reserve good trasfer case?

Thak you guys, I hope somebody study from my stupid try. Cheers from Hungary!
If anyone is interested, I can upload pictures of the damage, also sorry for my bad english