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96 auto trans lack of power 49-60 mph
hello I have a 96 2wd truck and tow a 14ft trailer with 3 quads 55gal of water a few cans of gas and camping stuff "3000-4000lbs" the truck just seems to be a dog on hills when in that 49-60mph the converter locks and it does not accelerate.
motor and trans are stock and original 180k on them truck feels good empty I'm new to the truck only put a few thousand miles on it seems to lock up at 50mph is this normal? when I push the gas harder or floor it it wont down shift it does not smoke at all wot up hills. when I pull out from a stop sign with the trailer it seems good tach goes to say 2000-2200 and kinda stays there thru the shifts then hits 50mph locks up tq converter and drops to 1500ish rpms which is fine except when on hills.. is this normal I tried to explain it the best I could I would like more power but I dont have money for a trans right now and am afraid I will be on borrowed time if I mod the power output am I correct? thanks Mike |
Pushing the O/D Off button has no effect ?
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Originally Posted by angelic0-
(Post 941693)
Pushing the O/D Off button has no effect ?
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Mine does the same thing with a trailer, the auto is a dog on hills with a stock engine. I was actually going to start a topic about it myself, looking for more high MPH/low RPM boost. I can enter the highway pulling a trailer with 30psi of boost pulling good right until it shifts into lockup, where the RPMs drop to 1500 and it falls flat on it's face. I can't get more than 10psi of boost @1500 RPM, and that's just plain not enough to keep accelerating with a trailer.
Similarly, maintaining speed with a trailer on the highway below 80mph is impossible. If I'm going 70mph at the bottom of a hill with it matted to the floor, I'll be lucky to be doing 55mph at the top. At 75-80mph, the RPMs are up around 2000 and there's 25+ psi of boost available with a quick stab of the throttle, and 80mph is enough provides enough momentum to get me to the top of most hills without losing more than 10mph of speed, but if I ever want to pull any kind of load and actually maintain 65-70mph, forget about it. I'm wondering if the issue is the lack of boost at low RPM in lockup, or not enough fuel. Based on my limited understanding of how these engines are set up, it makes sense to me that it's not enough fuel since changing the governor springs in the pump allows you to have enough fuel to spin more RPM, but I'd hate to go throwing more fuel at it and still be stuck under 10psi of boost @1500 RPM in lockup because it's something else. Direction appreciated! |
that is my issue to the T on the way home I was going fast like 75 or so on a bigger hill and could accererate no problem passing everyone the issue is most of my driving is thru the mountains going riding 45-60 mph
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If you aren't going over 55-60mph, turning off the OD will definitely help; the main problem is that that's as fast as you can go with it off, which is more of an issue on the highway where the speed limit is 65mph or more. I pretty much leave the OD off with a trailer unless the speed limit is over 55mph.
The reason it's easier to maintain speed @75mph or more is like I said, more boost is available at the higher RPMs. What it's doing is more obvious if you have a boost gauge and can watch it slam from 30psi down to 10psi the instant the converter locks. So my question is, is low RPM boost limited by fuel, something else, or both? |
how high is it safe to rev the motor to for a 1 mile long hill thou?
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If the engine is stock and running right, to the floor all day long, more or less. It won't let it rev past 2500 without making changes, and redline is 3000 Ergo, it won't let you run it over like, 80% duty cycle, which is what these engines were designed to run at.
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Originally Posted by JBearSVT
(Post 941735)
If the engine is stock and running right, to the floor all day long, more or less.
And with #60 or #120 valvesprings you can take it even further... 1mile trip with the pedal to the floor won't hurt anything... i've only got #60 springs and i will do 4000rpm with the 4k all day long without worrying about any damage... There's no timing chain or belt to worry about... these are ROUGH and TOUGH motors :tu: |
wow thanks I guess I'm just a pussy :argh: I start to get all worried over 2200 rpm or so
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Obviously it will put more wear on the engine than purring around at 1600 would, and your gas mileage will go to hell, but you aren't asking anything of it that Cummins didn't see coming when they designed it for a semi.
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I've posted it on another thread... but i'll copy it and paste it here:
Originally Posted by angelic0-
(Post 928246)
The Cummins factory in Columbus Indiana, send Dodge up to 700 6BT engines per DAY.
A whole bunch of Engineers mock the fact that Dodge are installing this engine in a pickup truck as it was designed for a duty cycle of 60-80% and could go for a 100% duty cycle for more than 1 hour with ease. This engine in a pickup truck doing normal load in highway / city usage will not even reach a load factor of 20%. In the past, Dodge used to compare internals of the Cummins vs NaviStar, Detroit 6.5 and the Duramax 6.6 as they have much smaller internals. This was even used as a marketing trick in Iceland. Cummins engines will without a doubt outlive their trucks in every normal situation, my Cummins has got it's beatings and it still runs strong although now it has a faulty water pump... My truck is listed in my signature (you probably have to look at my first post in this thread) and the chassis is screwed, wich is why i'm swapping into a 1500 Gasser... That way i get a lot of cool features, like a lighter truck and short bed... but i will never EVER cope with my truck being a 5.9 gasser... so it get's a Cummins transplant... I love my Cummins !!! ---AutoMerged DoublePost--- Not sure if that's right... BUT... I do see a big difference in using the BLUE fuel here (OFF-ROAD, EQUIPMENT FUEL) or even the RED fuel (NAVAL, SHIPS AND SEA)... both in means of power and consumption... The ON-ROAD non dyed oil will give me the best consumption, the BLUE is similar but will consume more and EGTs will be higher... But this RED stuff we're supposed to use on the boats is "Radioactive" to say the least !!! |
And then Dodge took this amazing powerplant and mated it with a Chrysler automatic so fragile that they had to starve it for fuel to keep it from grenading. All of which still leaves me wondering, is it gutless after the torque converter locks because it just needs more fuel, or is there something else too?
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ok I went for a drive and tried the no overdrive today and it went to about 2500 rpm and stayed there no problem but then it felt like it stopped pulling almost as if ya kinda put took it out of gear is that the govener kicking in ?
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You're going to have to be more descriptive of what happened. How long did it take? Stopped pulling as in the RPMs dropped, or that it stopped holding speed, or that it just stopped accelerating? What were the speed and time specifics?
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I have not taken it back out yet but seemed to get to 2500 to 2600 rpm then almost seemed as if it went into nuetral I let off the gas in panic for a second then got back on it and it went again but then just put it in OD .. wonder if it was cause I was on the flat accelerating pretty good and that is where it cuts fuel out or something?
I'll try it again next time I drive it.. thanks for all your help[ |
yes, that's most likely the governor kicking in, it's like someone is leveling out your throttle ?
it's not like you're hitting a brick wall or something ?
Originally Posted by JBearSVT
(Post 941791)
And then Dodge took this amazing powerplant and mated it with a Chrysler automatic so fragile that they had to starve it for fuel to keep it from grenading. All of which still leaves me wondering, is it gutless after the torque converter locks because it just needs more fuel, or is there something else too?
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Here's the thing: I can make more than 10psi of boost at 1500rpm, just not in OD. Which is to say, not over 55mph or so. If I'm in first or second at 1500rpm and stab the throttle I have 15psi before the tach needle even moves and 20psi just another second away. Once it's in OD though, that's it. Mash the throttle and it just sits there. I believe when the rear was rebuilt last year they told me it had 3.73's, which I hadn't heard of in these trucks, it seems like most of them are either 3.55's or 4.something's. I'm certainly open to trying anything though, especially if it's free. I haven't messed with fueling at all, either in the pump or the AFC. Which direction should I crank it?
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Thats the pump defueling, thats why you need 4k governer spring kit with 60 lbs valve springs :c:
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Been thinking about doing that for about a year now, for some reason it never occurred to me that it would raise my top speed with the OD off.
WTF was wrong with me? That's the best reason yet!:yeah: |
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