Hi Guys,

I have a 99 Cherokee 4WD that takes about 20-30 seconds to engage drive if left sitting for a few days or more.
Is there a drain back valve or some other component that I should check?

Thanks,

Seabee

Most diagrams I’ve seen show one at the cooler connection on the rad. On my 99 I changed the rad and didn’t see an obvious one, I replaced part of the inlet line as well. Haven’t had any issues with delay engagement even after it sits a while. Maybe there’s some other blockage in the trans? Try doing a few dump and fills, 3x with a bit of driving between should change out the complete volume of fluid. Be sure to use dex/merc as spec’d, not the new “equivalent “

I am pretty sure there is an anti drain back valve in the trans which prevents ATF draining from the TC and it is known to become defective and not easily repairable

It may be mentioned in the FSM AW4 rebuild Chapter, have you read that ?

ever done this 15 second maintenance?


What's the fluid level and condition? ever changed the fluid?

Thanks for the feedback. This is my "parts" Jeep, so no I haven't done anything to it. It runs great and shifts fine once engaged. I was just trying to determine whether the transmission was any good for a swap in and what I could do to it to make it better. I doubt that a simple oil change would make any difference, given the major symptoms. The anti-drain back valve at the cooler is intriguing.............

I don't believe there is a check valve at the cooler. The cooler is downstream of the trans and empties into the pan anyway.