Pulsating when letting off throttle.

[BassMaster]

It just started a couple days ago, in 2nd and 3rd gear, anytime I let off the throttle from accelerating the truck pulsates forward then backs off. Transmission?

[Onk]

Have you checked your fluids?

Remember to check tranny fluid when the motor is running

[BassMaster]

Everything is good. I checked it last weekend. I never had a problem until I put the Flowmaster back on there, started missing shifts again and now this crap.

[SmokedRam]

It could be a back pressure problem....how is your CAT?

[BassMaster]

That's actually what I have been thinking. Not sure, I'll take it in next week and have them check it. If it's the cat's ill probably save up for some LT's and just run those to an X.

Oh, I have no dash lights on and it's throwing no codes.

[SmokedRam]

is your cat welded on or bolted? If its bolted just take a hammer to the honey comb and hollow it out...

[BassMaster]

Stock cats. Stock all the way up to where the resonator used to be.

[AWE Daniel]

Adding a muffler wont do this, you need to check your tranny fluid like RS said, and have you messed with the throttle body at all recently, you may want to give that a good cleaning, and try recalibrating the throttle position, to do that all you need to do is turn the key to run without starting the motor and wait about 30 seconds (if you have a hemi, not sure about how with the 4.7s)

[MoparNC]

I agree....I would start at the Trans fluid.

Have you ever had it serviced? Are you still running on the original fluid from the factory? It may be time to do a flush

[SmokedRam]

depending on how many miles are on the fluid a flush might actually worsen things rather than help...but a clogged CAT or almost clogged CAT give the symptoms he is dealing with. I had a trans on an OBDII vehicle (NOT A MOPAR) that the trans started slipping...had the trans pressures checked and everything was in good spec...turns out a faulty coil pack was to blame...repaired it and all is now good. I guess all I am saying that with these electronically controlled vehicles the problem isn't always cut and dry or as direct as we think...

[AWE Daniel]

Just for some info, a common misconception is that these shops use a machine that has a high power flush, but they dont, they hook lines up to the tranny and use the trannys own fluid pump to replace the old fluid with new fluid. Just FYI

[SmokedRam]

Thats exactly right...however it can do more harm than good, depending on the age or mileage on the fluid. if you have gone 70K miles without changing the fluid, then normally only a filter/fluid change is in order. If you flush religiously, say every 30K miles, then it could benefit you, but you have to stay on top of those things.

[AWE Daniel]

You do filters and flush every 30K, but I thought you were talking about stuff breaking off in the tranny and clogging things up, everybody loves to say that will happen.

[SmokedRam]

The only time we get those kind of complaints here at our oil company is when people use our engine flush...which, is why we stopped selling it in North America...

[AWE Daniel]

Yeah I just follow the manual where it says never to use additives or cleaners, i figure they know more than i do.

[SmokedRam]

Yeah, additives are alright, but when we blend a milti-viscosity oil, we blend it in a way with additives already built in so the oil can do it's job properly. By adding additives to the oil, you can throw off the additive package we have built into it, so it might not do it's job properly. If you are using a single viscosity oil (SAE 30, SAE 40) where there a VERY little additives and 0 detergents in the oil, then additives are recommended.

[OklaHemi]

i had a dirty thought wheni read the title

[BassMaster]

I bought the truck used at 70k miles. I am now at 96k. I have no previous records of anything being done. I've been worried about changing the transmission fluid. Tomorrow before work, I will check it again to make sure it's alright. I had no problems with it at all today. It comes and goes..

[SmokedRam]

Bass...best thing to do is take some of the used fluid and wipe it on a plain white piece of paper...the spot should be light pink, not overly red...

[BassMaster]

Light Pink, looks brand new, and smells brand new. Step sister walked out, what are you sniffing.. Umm I can explain.

[Stealth Mode]

Hehe, I love my carburated vehicle's.

If it's violent pulsating. It's the tran's/diff. The diff will make a nasty screaming sound. Usually the tran's will too. One question. How does the transmission fluid smell?

$10 say's it's the cat.

[BassMaster]

Not something I want to smell all the time, I mean I didn't get enjoyment smelling it lol. Smells almost like a brand new bottle, definitely not burnt. I used to work in a quick lube and can tell the difference between burnt fluid.

No squealing, humming, etc. The only time it stutters is after about 3/4 throttle, it hangs for a second. And it's not constant either.

[Stealth Mode]

Dump the cat and enjoy some more power. I bet that Slowmaster is rusted on the inside though...

Get a good muffler and when you redo your exhaust, delete the cat's/resin's and do like 3" stainless or a true dual setup.

[SmokedRam]

Deleting the cat doesnt always equal more power...in most instances it can actually hurt HP. At the most I would either hollow it out a little, like I mentioned earlier in the thread or get a hi-flow cat.

[AWE Daniel]

I would get a look at those trans filters, and clean the throttle body!

[BassMaster]

Going to clean the TB next weekend. As for the filters, is that safe to do with my mileage? Like I said I have no idea of previous maintenance.

[SmokedRam]

Filters yeah...you might wanna take it down to Autozone and have it set for codes...just in case they are not triggering a CEL. I suggest Berrymans B12 Chemtool to clean your TB with...I swear by that stuff...

[BassMaster]

I used the one at work to check for codes, I'll take it to Auto Zone or Advanced on Friday and let you guys know.

[Stealth Mode]

Anyone ever had a Chrysler automatice go out on them? It DOESN'T give any warning. It may slip really hard once or twice but then that's it.

He's not going to hurt any hp/tq by deleting the cat's... And if you're talking about back pressure being his problem, that's a debate that's be debated out. The only way he can hurt on the hp/tq side by deleting the cat's is if he doesn't run a sufficent amount of exhaust.

How is a dirty TB going to 'cause fluttering while shifting? A dirty TB will make it run like crap. Even a mis-aligned throttle position sensor won't 'cause his issues'.

[BassMaster]

It's still stuff I need to do. This is my first Chrysler. I had a Chevy before this one, and I could easily tell that the transmission was going out.

[Redtruck-VA]

IMO, proper maintenance needs to be done especially on high mileage vehicles. It's a myth that something bad will happen if you disturb the accumulated crap thats builds up from ignoring maintenance. The truth lays closer to failure occurs from having dirty broken down oil. Personal choice.....

[Redtruck-VA]

Man, did I kill this thread or what?