what size tires are all of you running? I mean is the truck over tired and what rear end ratio do you have. I have a 3.7 with 265\65\17 and I lose 10-15 miles an hour on a big 1.5 mile climb on a fairly steep hill 8% grade and kinda consider that normal start at 65 top the hill at 50-55 . its only a 6 cyl and its a heavy bitch too. I have a new trans and new convertor so its not slipping

 

regg - you've got a 6 cyl. What you describe is as best can be expected.

Over here; 4.7 4wd with 3.52 gearing 245/70R17 in the winter 265/65R17 summer. Only time there is ever a sense of a power problem is when It is hooked to the 6000# trailer full of power toys. The problem we have with the 4.7 is the abysmal mpg.

 

agreed. The 6 get horrible mpg also. 13-14 round town and 15-16 on the highway. I had a 2003 chevy Silverado extra cab with a TBI 350. and it got better mileage than this 6 with no power deficets

 

Ok so the other day the truck started shaking a bit when I pressed on the gas. I have been through that before and new the battery was going out. I replaced the battery and BAM power back like crazy... A train couldn't hold my truck back. The next day I was out driving again and started losing power again and also the shaking feeling came back. So now thinking it's the alternator, might also be the brain. Truck still not throwing a single code at all. That leads me to think brain but replacing alternator is cheaper so I will go with that first. Has anyone else had similar problem?

 

I replaced the Alt, and here is the current finding. My tranny was toast, so it needed replacing but was a secondary problem not related to power issue. The culprit was the Alt. It would run ok for a short time then mess up and spike or drop a load. Bench test ran for sometime before figuring this out. That is why the dealership showed no issues and couldn't trace it back. I installed a new Alt and added water to the battery. Also reset the computer. For a few days it ran worse then ever before. Just recently it began acting like it should. The complete power is not back yet but I would say its at 70%. I am going to change out plugs and wires since it taxed the system. But 70% is better then the 30% it was doing. gas mileage was down to 11/13.....currently now getting 16/20. Still have a small delay (1 or 2 seconds) when hitting the gas going uphill but no where close to how bad it was before ( 6 seconds). I did find out that there really is no way to test the power controller. So if after plugs and wires I don't get 100%, then I will check out the computer. I'll let you all know how it goes. One more thing. i still have problems going up hill in reverse. I will check that out as well soon.

 

All that fussing and it was not giving any OBD codes?

 

I found this thread when I searched how to improve my 2008 3.7 Dakota.
I'm dealing with the same issue(s) and there is a big difference that makes me believe that it could be 1 thing causing it....
the big difference is, I have the 6 speed manual transmission....so, I think that the GEAR RATIO in the rear end may be the culprit?
I'm definitely not saying that I know for a fact but, if I keep it, I'm changing it just to see.
The veteran mentioned his having 3:52 gears....if I have those then I might need 3:7(?)
It's a 2008 ST and just turned 40k miles(yes, this is Wednesday March 9th, 2022 ....got it from the original owners family when he passed away so we know also that *if it is something internally with engine, tranny, etc. then we should push for a recall 🤔
Well, I'm not sure if I will get a response from anyone but I would like to know if anyone has done anything to help this.....the stalling under load/going uphill 👍

 

My 2001 ram 1500 V6 magnum can be cruising along at 75mph but, when I go uphill my speed decreases. But I don't believe the problem is in the transmission because mine is a standard tranny. I can downshift and it helps some depending on how steep the hill is. So, I don't think it is a shifting issue your dealing with. Granted, I'm just a YouTube mechanic. That's how I've learned most of what little I know. It just doesn't seem to make sense that we would have the same issue and that it would be a transmission shifting problem, if one is automatic and one is standard. Because mine shifts just fine and I still have the issue with losing mph. I'm leaning more towards starving for fuel or air. My personal ignorant opinion is a very small leak in the fuel system somewhere, maybe vacuum lines. Again, I'm just guessing at this point but, I don't think our problem is in the transmission. The only code that shows on mine is PO442 Evaporative emissions system leak. I'm about to try Veterans suggested fix.