Pointers for replacing a transmission

[PTG in MN]

Hi Guys,

I have a manual "three on the tree" transmission with a bad crack on the transmission housing fluid leaks everywhere so I found a used one that I plan to swap out coming up in the next couple weeks.

Just a note the used transmission still has the dana 20 transfer case attached to it.

I have a couple questions.
-Is it easier to just remove the old transmission and transfer case as a unit and put the new "unit" in, or separate them out and just install the transmission. Mind you my current transfer case is fine.
-Are there any gaskets (motor or transmission) that make sense to replace while the transmission is pulled.
-Any other things you suggest doing while the transmission is pulled.
-Any pointers you can give for the transmission swap

Thanks for any pointers you can send my way.

Paul

 

[Broncobowsher]

Make sure you have the right transmission (V8 and I6 do not swap)
Now is a really good time to think about a clutch while the transmission is out. Even if it is good I would still consider a throwout bearing if you know the old one is old.
No gaskets between the engine and the transmission.
I generally pull the transmission and transfer case attached. The transfer case shift linkage can be a bear to get to. If you pull the crossmember and drop it an inch or two there is a lot more hand clearance. Don't drop it too much or you can put the fan into the radiator.
Transmission jacks are your friend.

 

[Izzy]

I vote to seperate them. They each weigh around 100 pounds so together, it gets heavy quick but seperated, they are manageable.

 

[BroncoDawg]

Go four speed while it is apart and never look back. Your clutch will love you and not a tough swap. Just sayin'.

 

[KyleQ]

Go four speed while it is apart and never look back. Your clutch will love you and not a tough swap. Just sayin'.

I second this - time for a 435 ;D