Help please before I scrap it.

[my98ramquad]

First of all thank you in advance for any leads and/or the cause. I have a 98 Ram 1500 quad cab 5.9 2wd auto. When I purchased the truck I noticed that it had a newer rebuild of the transmission and had the typical ball joint squeaks plus the whine in the diff. So started off with a complete overhaul of the diff (ring and pinion the only thing left original). Did the ball joints plus a few other things. Well out of no where a year later the truck starts bucking around 50-60 mph on a steady throttle. Only does it after it is at operating temp and if I shut it off and restart it, it will be fine for about 10 minutes then back to the bucking/slipping. I say bucking/slipping because I noticed the tach bouncing up and down when it was doing it's symptom. And here we go with the list. Took it to my transmission guy and he noticed burn/hot spots on the converter. In goes a new converter and it's still there. Take it back and commenced in rebuilding the trans and was advised the hard parts were fine but the clutches and bands were shot. Pick truck up and again started right back up and on the way back to the shop it started down shifting all by itself and locked in first gear. Was advised it was solenoids bad and now they are new. And guess what it's still doing the same crap. Has anyone had anything like this or any ideas what it could be pointing to? Hopefully there is an answer soon or it is going to be the biggest gas grill on my street. Thanks

 

[SYKRAMMAN]

Plugged cats? Bad 02 sensors? Any cel’s?

 

[my98ramquad]

Only had one cel and it was #6 cylinder random misfire. Went ahead and did the whole tune up even though everything looked good and no change. I have no rotten egg smell or pressure difference for the cats. Have not done the O2s, just ordered both and waiting for them to get here.

 

[dodge dude94]

Turn OD off and see what it does.

 

[NCRaineman]

Turn OD off and see what it does.

That's a good thought... might be slipping trying to go into OD.

 

[my98ramquad]

Turn OD off and see what it does.

Thanks for the replies everyone. When this all first started I was in and out of O/D and it didn't make a difference. That is when I took it to my trans guy and he found the torque converter had heat spots. New torque converter and $300 later it still did the same thing. Back to the shop, rebuild and $600 later is when the interesting stuff started. It only did the bucking and stuttering when at operating temp and went from the 45 mph range to the 50ish to 65 mph range. After about a week it started acting like it was downshifting after letting off the gas pedal and literally nosing over like it was a manual trans slinging the clutch out after hard downshift. By the time I made it home (about 8 miles) I only had 1st gear, O/D off light on, trans temp light on, and barely had reverse. The next morning had it towed back to my guy and ironically as soon as it came off the wrecker it drove down the road shifting fine and no lights until operating temp. It did the exact same as the day before. New solenoids later it shifted good, O/D was actually shifting into it at a lower speed and was smooth. Until operating temp again started the same old stuff. Now mind you this has been going on since mid December. Reason being I live in Florida and also have a motorcycle. With all the bike rallies, weeks, cruise ins, etc. the bike has seen some miles. Now with it being Hurricane season it rains a whole lot more and the Rhino gets driven a little more. Again thank you all for the ideas it is greatly appreciated. O2's should be here Tuesday and we will see what happens.

 

[BWL]

Could it be something so simple as a plugged fuel filter and when you shut the truck off and restart the fuel pump pressures the system again when it cycles prestart and you slowly lose fuel pressure as you drive along from the restriction.