Hey guys, I received my replacement t case and will swap it out this weekend. Question, how did you remove the rear propeller shaft? The one I received still has the rear shaft attached and it is STUCK. Bolts are out but it seems pressed into the t case and will take some effort to remove. I’ve already tried beating on it with a 5 lb hammer…. No luck. Tried heat.. no luck.

any advice helps.

 

If you don't need to re-use it, use a good sharp chisel into the rear shaft just behind the actual flange from the t-case, and hammer it into the shaft at an angle. Allows you to use the hammer hits to drive it out of the flange. Rotate and alternate hits from opposite sides, it should pop free eventually. They do get quite locked in there.

 

Here you go. This Tcase is extremely simple. One clutch pack that is hydraulically activated via pump. When pack is pressurized, the input/rear output is coupled to the front output. I found half of the pack welded solid, resulting in the front output coupled to the rear 100% of the time. It amazes me that the bond between clutch discs was strong enough to hold against the torque the front output would see when pack wasn’t pressurized. Ideas on cause? Weak/blocked pump? Bad seal on clutch pack piston? I’ll try to dig further tomorrow.



The fat stack of discs is welded together

 

The other half of the case

Oil drains down into pump pickup area

Oil has to drain through this. It is extremely clogged. It is the possible point of failure. If pump doesn’t get a constant flow of oil, the clutch pack can’t hold tight. It will slip and create heat… and weld itself together.

 

The clutch pack isn’t like a transmission clutch pack with a molded piston with a rubber lip. I was looking for one that was possibly leaking… it doesn’t have one. My best guess is that it failed due to insufficient oil flow back to the pump.

 

Question. So, draining/changing the fluid in the transfer case won't remove all the crud that has built up?

 

I would say that changing the fluid is the only thing we can do to prolong the life of the unit. It's hard to say if the failure (friction material being destroyed) caused the clogging or vice versa. The plastic "restrictor" has obvious signs of melting, likely from hot friction/steel material passing through it. It seems it was possibly a snowball failure that compounded once the frictions and steels started failing. Another thought is that the fluid degraded enough to stop providing lubrication between the friction and the steels. Either way, changing fluid is important, it seems.