2001 Ram 1500 5.2 4x4, AAMCO tranny rebuild 30,000 miles ago - Has been running fine for a year IN-TOWN. Went on a 1200 mile trip when things started to act up. After 500 miles a person following said he noticed a puff of white smoke from under the truck (not form the tailpipe) when slowing down for a gas stop. I did not feel a thing. Arrived at destination (600 mile) and spent a week on vacation. Coming home, after 200 miles I noticed something was not right. Cruising the Interstate at 70 mph with rpm at +/- 1500, I noticed a 'shutter' or a slip in the way it felt while cruising. It progressively got worse. Seems like at 1500 rpm and 50 mph or higher, it will 'slip' , but just for a second. I did notice that the rpm will jump from 1500 to 1800 rpm when it happens - and it will happen a lot. If I 'goose it' and step on the gas (like I'm passing another vehicle) all seems well. If I drop below 50 mph, all seems well.
After a week back home, I threw a P0300 code (general cylinder misfire) early in the morning. It ran like "dooky" going to work, but seemed fine going home. I pulled the neg battery cable to clear the code, and it has run fine for 2 weeks now - albeit below 45 mph. I did take it on the highway to get it up to speed and at 50 mph the slip/shutter came back - although no code has shown up.
Could these 2 incidents be related?
Does this seem like a clutch slip, torque converter, tranny problem, or maybe computer problem?
I'm at a loss at the moment on who I should bring it to.

 

General misfires can be a lot of things. The shuttering makes me guess TPS, but the puff of smoke and crappy running could be the cat. A dying coil might also cause poor running and general misfires, but shouldn't at a specific speed all the time. Also, a clogged or malfunctioning PCV can cause weird problems, but again, I wouldn't think it would be repeatable at the same place in the RPM's.

Is the stock catalytic converter on there still? If yes, have it tested at an exhaust shop and replaced if necessary.
Try replacing the TPS on the side of the throttle body, it can make shifting very erratic at times and cause funky issues like that.

 

I tried cleaning the TPS per the DIY tutorial, instead of buying the $37 Autozone unit. (Times are lean). Took it for a 30 minute test run and it still shuttered (once), but it seems much more infrequent and runs a little better. Granted it was a quick trip and it hadn't warmed up enough? Won't be able to put it through a longer test until next weekend. One thing I didn't do is reset the computer. Think this would make a difference? Possibly it didn't clean up enough and I still need to buy a new TPS?
Thoughts?!

 

Well, the TPS change didn't work. I bought a new one and replaced it. Reset the computer after installation. It seemed fine when cold and I had high hopes for a quick fix. After it got up to operating temperature - the stumble is back. Seems like it is trying to jump in out of the upper gear, maybe?
Dang thing was rebuilt only 18,000 miles ago - not 30,000. (of course it is now out of AAMCO warranty)
Any other thoughts?
Whatcha think, MonteC?

 

Bad converter clutch. Plus you had it rebuilt at AAMCO, they probably just spray painted your old converter and charged you for a new one. Ive seen it a hundred times.


Try and find a product made by "Smart Blend" OR "Lube Guard", both companies make a wide array of additives, look for the one designed to eliminate converter slip/shudder. These are the ONLY two companies that you should buy additives from. I prefer Smart Blend.

 

Thanx, MonteC for your reply.
I've got some "Smart Blend Synthetic Instant Shudder Eliminator" on the way that I got on the internet from the manufacturer. $8.95 + 90¢ shipping via mail.
(http://lifeautomotive.com/Products/ATFP3800.asp)
Do I just add it to the fill tube? Do I need to drain some fluid out beforehand?
Will post results when it comes in and I give it a try.

 

Get the truck nice and hot, shake up the additive and dump it in , then drive around for another 15 minutes. No need to take out any fluid, and dump it right down the dipstick tube.

 

Yeah, your main problem is having AAMCO rebuild the transmission, never trust big chain transmission shops like that.

All
Automatics
Must
Come
Out

 

Sorry to thread jack, but does your truck really run at 1500 rpms at 70 mph? Why does mine run at 2100?

 

Rear end gear ratio.