Diff Dana 20 overfilling from Trans?

[Greenweenie44]

Hi all, I’ve got a T-15 with Dana 20 . Last week I noticed my Transfer Case was a little over full and Transmission a little low. I cleaned vent and got fluid levels corrected. Checked it again today and same thing- Transmission low and Transfer Case over full. I was told the T-15 and Dana 20 share fluid and that there is no “seal” between them, so I’m a little mystified as to how this is happening. Any advice appreciated.

 

[CJ]

It's pretty common. What oil are you using and how full / under are we talking? (pints)
Does it return to the same level(s) each time?
What shape are your motor and Transmission mounts? Has the Transmission been lowered for a drive line alignment issue?
There is no seal and the level is set by the bearings, after driving the levels will settle to their 'Happy Level Place.'

See -->> https://jeep-cj.com/community/threads/dana-20-over-fill.58545/

 

[Greenweenie44]

GL 4 80W-90. It’s not overfilled a lot. Goes to thin stream pretty quickly after I pull plug. Might be 1/4 to 1/2 pint at most. Had new motor/Transmission mounts put in December. No alignment issues. Maybe I’m pole vaulting over rat turds?

 

[CJ]

1/4 to 1/2 pint is OK. You can stop your vaulting!!! (sweating the small stuff)

 

[Greenweenie44]

Thanks buddy. I’m putting the stick down now.