Turbocube

I have a 1995 Jeep XJ w/ a 1996 engine (was replaced under warranty ages ago), AW4 automatic transmission, and the 2WD model, although I am planning a 4x4 conversion later this year.

I'm having a strange and annoying problem that my searching hasn't been able to solve. This Jeep runs very well, only major work I've done besides regular maintenance is an exhaust overhaul w/ headers, Magnaflow cat, Flowmaster muffler and all new pipes in between. Engine has been taken very good care of its entire life (especially by me) and has 158,000 miles. Transmission fluid is bright red, at the proper level and I've done a drain-fill recently, as well as inspected the flex plate for cracks. In fact I've replaced every fluid including the differential. CPS and TPS was replaced when I overhauled the exhaust, and I do the shift cable adjustment thing every month. I've also replaced the spark plugs last month.

Now onto the problem: I'll be cruising along at 45/50MPH, I guess its in overdrive judging from the sound, and as soon as I reach a hill the RPMs drop really fast, and the transmission doesn't downshift or do anything. I don't have a tachometer but if I don't give it significant gas the RPMs will drop very low judging from the sound. It sounds awful really, like the engine is struggling to stay running! I can hit a hill at 55MPH and if I don't give it plenty of gas the transmission will just do nothing and I'll end up cresting the hill at 30MPH with the RPMs sounding barely above idle... its as if I am driving a manual and trying to climb a 45 degree incline in 5th gear. If I let off the throttle and get back on it, it acts normal again until it shifts into what I think is overdrive, then does it again. If its doing it, and I floor it, it downshifts and flies right up the hill no problem. So, it clearly doesn't lack power, but won't downshift automatically on an incline, making it impossible for me to maintain a constant speed when driving through a hilly area.

Any ideas on what might be causing this, or how I can fix it? Its driving me nuts!

scottmphoto

You might try adjusting the transmission kick-down cable on the throttle body. There's a good write-up on here somewhere. I'm on my phone or I'd post the link. I will post it later if I get the chance to get on the laptop.

scottmphoto

Ok, here's the link that I was thinking of:


https://www.cherokeeforum.com/f2/free-quick-fix-41821/

Turbocube

I have already tried that to no avail, unfortunately. Unless rather than the usual adjustment procedure there were some way to set the cable to kick down "early" which for me would be right on time?

Turbocube

I went ahead and did the cable adjustment, but instead of sticking with the position the cable ratcheted itself to, I pushed it back one click tighter. This has made noticeable difference, it stays in each gear longer and actually seems to be responding to changes in grade. I'm pretty happy with it.

Rockfrog

I didn't adjust mine at the throttle body last time, I did it from the pedal instead, seems to have made a difference, it used to hang just like you mentioned now it down shifts just past half throttle and again just before WOT if I'm in OD