Hey guys, I've been reading on here for a while and finally have something to ask. I just bought a 99 2500, auto, 4x4 with a 5.9 and 141,000 miles on it. The under hood tag says it's got a Dana 6 front with 3.5 gears, I'm guessing zero is faded for the 60, and a 241 Heavy transfercase. From what I've understood the 60 front and HD241 was for the Cummins' so maybe it was optioned when new or maybe I just have a junkyard hood on the truck.

The first issue is a lack of power. The truck seems a little more sluggish than I was expecting out of the 5.9, but the older dodge's I've driven in the past have all been 4.10 geared.

As far as the tranny goes, it shifts fairly smoothly through all 4 gears, but on the way home (2 hour trip on the interstate) 70mph wanted to kick in and out of OD with every slight hill so I locked it out of OD. Even still by the top of most hills it would downshift to 2nd. If I used the cruise control it would downshift about the same, but even coasting down the backside of the hill it would never up shift back into 3rd. If I took the cruise off and drove with the pedal it would shift back into 3rd just fine.

I've got a scanner that can monitor live data while driving and it's showing no codes and the tps operation is nice and smooth, but shows around 12% even with the motor off. I've seen a few other members reporting a similar reading, but haven't seen whether or not it indicates a bad sensor so I'm going to check it with a voltmeter to be sure.

I plan on checking the plenum gasket in the next couple days and if it's not done already add the aluminum plate. I'm also going to check the cat to see if it's plugged by either removing the upstream o2 sensor and driving it or using a pressure gauge before and after the cat.

As far as the tranny, looking under the hood it appears there is a tranny cooler ahead of the radiator and the lines might be bypassing the cooler in the radiator, but it was dark so i didn't look too closely. The hard tranny lines that run beside the engine have been cut with rubber line hose clamped to it and run forward of the radiator so I think the check valve has been removed as well.

The fluid was full and looked/smelled good, but it didn't smell like the Mopar ATF+4 I've installed in some vehicles while I worked at a tire shop; it smelled more like Dexron/Mercon but that's not much of an indicator. Regardless I'm going to change the filter soon. Is the parts house ATF+4 ok or should I get some actual Mopar brand from dealership? (there's not one local so I'll have to get it out of town) When I drop the pan i'm going to adjust the bands as well and maybe get a deep pan I've seen guys install that already has a drain plug for future service.

Thanks to anyone still reading, this got a little longer than I expected.
Is there anything else I might be missing? I've thought about changing the solenoids in the tranny since I don't know what fluid was used in it, but that will depend on how soon I can get some as I'd like to get the fluid changed sooner than later.

thanks for the help

 

I still find it amazing that they would put 3:55 gears in a 2500(which is part of the problem). But you are going in the right direction. Check the TPS per manual. Check for stored codes, and of course the plenum and cat.

BTW, what size tires are on it?

 

All of the 2500/3500 trucks got the D60 front, and 241 t-case. Rear axles vary by weight rating, and engine/trans combo. You should have a D60 rear as well.

You probably have a blown plenum, and a cat on its way out. Both will contribute to a lack of power. With the mileage you have on your engine, new timing set would be a very good idea as well. (this single 'mod' made the biggest difference in perceived power on my truck.)

 

Thanks for the quick responses. I still need to pick up a manual for the truck, but from what I've read so far checking the tps is a matter of checking for ~1 volt at closed to ~ 3.5 volts at open and a smooth transition in between when checking with an analog voltmeter.

As far as codes go, I'm showing no pending or permanent codes. One thing I forgot to mention is the previous owner changed the battery within the last month. I would imagine that most any codes this might have cleared should have shown up by now but I'll have to keep an eye out. In the meantime maybe I'll reset the pcm and re train it, I'm hoping it's not very accurate, but the overhead console computer started out at 9.8 avg mileage and by the time I got home went down to 8.8!

I do recall the rear axle being listed as a Dana 60 as well, HeyYou, but in the older 3/4 ton trucks I'm used to, the 60 was the smallest rear they put in them so it didn't seem noteworthy at the time.

Thanks for the help and Happy Thanksgiving to everyone.

 

You can download a free 2001 FSM from the FAQ/DIY section. And get one of these from Dodge. http://www.dodge.com/wccsapp/univers...ull&category=U

 

Do you have a rough idle to go with your lack of power? Or a hesitation from start? These are other symptoms of a bad TPS, but they may not be present even if it is the TPS.

 

The truck idles smoothly at iirc 700 rpms and acceleration is also very smooth so I was suspecting the cat being plugged and maybe the fuel mixture is getting oil.

 

You could pull your #8 plug as well and take a look at it. You'll see issues there if you have a plenum problem.

 

And the shift hunting in and out of OD could be the TV cable. Check and adjust if needed.

 

Sounds great everyone. I've already got the build sheet for my truck on it's way and I'll download the FSM so I can check out the TV cable. I did finally get a code last night while driving, no surprise really though, a P0420 Catalytic converter code so I'm fairly certain the cat will be coming off soon.

Hopefully I can get things in working order soon, I bought a newer truck hoping to get away from 8mpg on the highway lol.

Again, thanks for the help