It feels like my 2003 Liberty with 120k miles on it shifts up too early and the car rattles at aournd 1500 rpm @ speed around 60mph. If I push the pedal it downshifts and runs well once it picks up speed. Is my transmission about to die?
Has the battery been disconnected for any reason lately? If yes, the computer controlling the transmission could default to factory settings and have to relearn the shift points.
If no, the torque converter could be locking up and unlccking erratically or with to much noticeable jerking.
When was your last transmission service? What was done, flush or fluid/filter change? Who did it? Sometimes the wrong fluid in the transmission can make for lots of shift issues.
Sounds like you’re talking about when the converter locks up. Tap the brake when it’s rattling (just so the light turns on - use your left foot and keep constant pressure on the gas pedal). I’m surprised that you can sense it at that speed.
Was this bought new and is a relatively new event, or is this a new car to you and you’re wondering if it’s normal? 1500rpm is kinda low for the lock up, imo. Maybe not. My Wrangler goes to 1800 from 2000 if I’m fuel squeezing it (not that you can really squeeze fuel in a Wrangler).
…but for the time being, is this ignition ping that you’re hearing or is it an overall “groan” from the engine/chassis. When the converter locks up (which should be occurring at other times than JUST @ 60mph) it will give a “strained” sensation in some engine/trans combo’s.
If ignition ping, I’d recommend a fuel injector cleaner like Regane Complete, Techron Concentrate, Amsoil PI, and there’s a Redline product that works well. They contain the PEA agent that works very well at cleaning combustion chambers.
I did disconnect the battery a month or so ago but I am not 100% sure if the problem started after that or before that, at any rate it is quite possible. I did however change the oil in the transmission last week (Jiffy lube) in hope to fix it but nothing changed.
If it is the torque converter locking up - is that repariable and should I expect $$$ or $$$$? thanks for your replies!
I’ll try the brake thing. I’ve had the Jeep for the past 3 years and that started a month or so ago, JUST after I paid it off 
The rattling is as if you drive a stick shift on 4th gear and the speed drops too low for 4th gear - this type of ratling but not that violent. Thanks for your response.
Yeah sounds like it just need to re-learn your driving style. I know the auto transmission on my VW is awful for a while after battery disconnection, but it gets better in time. To “teach” it, you’ll want to push harder on the pedal whenever it makes an undesirable upshift, and try and get it to kick down if you can.
Is that the same transmission as the v6 Dakota?.My Dakota has always shifted like that(by the way you should probaly be on your 2nd transmission service by now)-Kevin(my vehicle has 3.92 gears.As a caveat it acts similar not exactlylike yours)