Auto Transmission shift issues

Ok heres my issues. 2008 Sahara 4dr, 45000 miles with auto trans, 2 1/2" lift on 275/70/18 tires and stock gears as far as I know, bought it the way it sits. Yesterday I was driving around 50mph and the transmission was trying to go into o/d while I was goin up a small incline and when it tried to shift it shuddered, like felt the jeep vibrate shuddered. It went in then out of o/d a couple times but it only shuddered the one time. I punched the o/d off, light on the dash showed it was off, button hoping to keep it out of o/d until I got to the house but it wouldn't come out of o/d even after turning the o/d off and on. I was pretty close to the house by this point and when I slowed down to turn into my neighborhood it shifted normally...no issues.

This morning I was going to trailer my motorcycle to a place I always go to ride so when I left the driveway I had the o/d off like Ive done the two other times Ive had the trailer hooked up. As I came out of the neighborhood it felt like it was trying to go into o/d even though I had it off and when it did I got the jeep shaking shudder again. I physically shifted it down to 2nd and the shudder stopped. I hit the o/d off button several times while I was moving and it finally acted like o/d wasnt engaged. Drove the 30ish miles to my spot and the whole time it kept acting like it was wanting to shift into o/d, like a little hesitation type feeling but it would stay in the correct gear. When I get to where I ride I put it into 2nd cause its a lot of slowish switchback turns going uphill. The jeep pulled just fine, no shudders, but it was still trying to shift into the next gear up...rpms would drop a little and then back up. It's like it wasnt recognizing that I had it in 2nd or something.

Leaving this afternoon I turned the o/d off as usual but still experienced the "trying to shift into o/d" issue. As I was coming thru a slow sharp turn, paved road, the traction control light started flashing for just a second like I was loosing grip but I wasnt. I turned the traction control off and after that had no issues with the transmission trying to shift into o/d. Its like turning it off fixed the crazy shift issues.

I checked the fluid level and its good. Ive had it for 5 months and its always shifted smoothly and still does. It doesnt feel like its slipping at all when driving/pulling the trailer but the shudder and trying to shift when it shouldnt has me confused. Anyone have any thoughts or ideas what to look for??

With 45000 miles have you or the previous owner ever changed transmision oli and filter?:thinking:

It doesnt look like the skid plate or the pan has been off. Im planning on adding an extra transmission cooler this weekend so im gonna change the fluid/filter then. Would dirty/old fluid cause these types of shift problems??

dirty fluid or burnt fluid would cause shifting problems. do you have a programmer tune on it?the automatic on my 2010 started shifting funny I ended up disconnecting the ground off the battery and just resetting it, been fine since

also check your shift linkage you may have to remove the console but also look underneath the jeep.there is a plastic bushing that will break and that may not be letting you get fully into gear

Not sure about the tune. Ive not done anything to it since I got it in January so its possible it has one and I just don't know it. I checked the cable from the body to the linkage on the tranny and from what I can feel/see nothings broken. Im definitely dropping the pan this weekend and changing the filter/fluid and Ill try disconnecting the battery too. Thanks for the advice.

Jeepers46 said:

Not sure about the tune. Ive not done anything to it since I got it in January so its possible it has one and I just don't know it. I checked the cable from the body to the linkage on the tranny and from what I can feel/see nothings broken. Im definitely dropping the pan this weekend and changing the filter/fluid and Ill try disconnecting the battery too. Thanks for the advice.

Click to expand...

:thumb::thumb::thumb:

Let us know if anything changed after. :beer:

Did the service this weekend and added the trans cooler. Took it for a test drive and it seems to shift much better and it feels like it might actually "pull" a little stronger under acceleration. My issue now is I cant seem to get any fluid to appear on the dipstick. I initially put 4qts in and it didnt show on the stick...added 1/2 a quart and it was about halfway between the cold and hot marks. Took it for a test drive and it shifted great but twice it acted like it went out of gear, as in slowing down to turn...give gas to accelerate and nothing happen. Made it home, left it running, and checked the level and there wasnt any fluid showing now??. Overall I added 5.5 quarts and its still barely showing while hot, in park and idling. Is it possible I still need to add even more fluid?? Im paranoid about over filling and scared to death of not having enough.

I need to add that I followed the warm up, cycle each gear for 30 seconds then check level procedure.

Sounds like you need to add more for sure. If your worried about over filling just add small portions and keep rechecking.

depends on the cooler but mine took about an extra quart.