Transmission Help! 45RFE

[Daveos]

I've had a lot of luck on this forum over the last few years getting stuff figured out with my Jeep. Have another issue I cant seem to figure out.

My 45RFE is slow to engage when it is hot. But it is not just when it is hot. It is only after it is hot and has sat for about 15 minutes. No symptoms at all when it is cold.

Fluid level is good
Was changed less than 30K ago

- If it is cold, it engages drive (1st) fine.
- If it is hot and has only been sitting for about 5 minutes, it engages fine.
- If it is hot and has been setting for 15 minutes + it wont engage drive right away. There is a 10 - 20 second delay. It slowly engages.
- If it is hot and has been sitting for more than 15 minutes, and I start it up and rev it for about 10 seconds, it engages fine.
- After it engages when hot and sitting for a while, it shifts between other gears fine.

Can the TC be causing this?
Fluid pressure too low when it is hot?
Possibly a solenoid?
Could a Transmission cooler help?
I changed the coolant temp sensor, possible this is malfunctioning?

Thanks for any help!!!!

 

[04Liberty]

I would say it sounds like converter drainback, but this almost always happens when it is cold, and you're saying it doesn't happen at all when it is cold?

 

[Daveos]

Yeah, it only happens after sitting when it's hot. I came across this TSB, sounds exactly like what is going on but my ****** isn't the right year. ?

http://www.jeepkj.com/forum/f212/tsb-21-016-05-delayed-engagement-after-extended-off-period-27663/

Is there any way to test if it is the Transfer Case? I don't recall if I had this issue before I changed the Transfer Case out a few years ago.

This seems like it fits the bill. Last time I did this I got the filter kit from O'Reiley, not sure if it is causing the issues.

http://www.wkjeeps.com/tsb/tsb_wk_2101505.pdf

Note "It is not detrimental to the transmission". That would explain why I've been dealing with this for about 2 years and it hasn't crapped out on me.

 

[04Liberty]

Usually TC drainabck happens because the non oem filters have an issue with the internal check valve or something to that effect, which allows the fluid to drain out of the TC.