I tried the search and haven't found an answer so hopefully someone has some insight on this. I dropped the fluid pan on my auto trans this weekend and changed the filter. I added 4 quarts of ATF+4 in through the dipstick just like the instructions on the Project JK site. Followed everything exactly but unfortunately I'm having some problems. When I start rolling it engages in 1st no prob but when it goes to shift into second it slips and revs the engine up. It usually catches after a few seconds and then once I've been rolling for a few minutes it's fine. When I checked the fluid I was a touch on the high side but with out a drain plug I haven't had a chance to drain the excess fluid. Could this be causing the problem? It hadn't done this a single time before the fluid change and now it has done it every time (4 times) that I've driven it since I changed it. Thoughts?
Thanks
-Mike

 

What did the dealership say? Do you still have warranty?

 

I know some vehicles have touchy transmissions but haven't heard anything about the JK.

 

I think overfilling a transmission can be just as bad if not worse than underfilling it. This is just what I remember reading somewhere. If there is too much fluid, the fluid can foam, and foamed fluid causes erratic shifting, noise and slipping problems. (what you have) The fluid can also overheat. I would drain some before I drove it more. You don't have to drop the pan to do it, if you can find a hard walled plastic tubing that can fit into the fill tube you can gravity drain it from there.

 

I ran my transmission low for a few days when I was checking the level wrong. I was checking it hot when the engine off rather then idling. I was 1/2 a quart low and didn't notice a difference. Now I have it right at the bottom of the hot mark.

 

When you changed the fluid, and the filter , if the O ring didn't seat properly, or the old one stayed behind, that would interfere with fluid being drawn up and cause problems . It would suck air instead of fluid and foam.

 

Possibly. It's there for a reason. I know with oil filters, if the old O Ring stays behind, you'll end up shooting oil all over your driveway the second you turn on the engine.