'02 3500 gas(auto) dually flatbed dump, 60K mi. is what I've got and here's my problem:

Hauling dirt for a friend, had to back up a short hill to dump out my pretty heavy load. Tranny started growling/ kinda a low pitched howl - it sounded like the tires were rubbing on the frame or something I thought at first but then it immediately quit backing up the hill so I dumped out and took off. I hit the hiway and got up to about 30-40mph and it downshifted abruptly enough(musta jumped at least 2 gears down) to make the tires skid a bit or at least it felt like it. Came to a stop, tried it again - same thing. Went to make a 3 point turn to get it back to my friends place and reverse barely worked enough to get me turned around. Limped on back to my friends place at 10mph and parked it. Tried reverse then to move it, totally out - NO reverse at all now. ATF smelled non-burnt and was full on the stick when running(checked it in park, did'nt know it should be in neutral at the time). Had a tow truck bring it home so I could hopefully fix it myself.

Looked up here on the pewter and saw the 2 sensors/governors which control shifting frequently go out. I planned on replacing these myself along with the filters/fluid and hoping for the best.

I've been searching here for over 3 hours now and have learned when the abrupt downshifting is a problem usually it is the valve body screwed up which I know nothing AT ALL about. I guess my question is, if the governor/solenoids ARE defective, could they cause the tranny to abruptly downshift as it does(is it even worth a try replacing these?) or is the valve body always the cause of this?

I just thought I'd ask here first before I spend my time and also money on wasted ATF if I gotta have the thing towed in to be taken apart again for a proffessional to fix it.

Any info or input greatly appreciated,


Thanks

 

The best place to start is to connect a scanner to the OBD port and see if any DTC's have been set. If so, it will at least get you started in the right direction

 

Thanks for the reply GF. I was hoping maybe just replacing the 2 sensor/governor items may fix it but no one here seems to have encountered this problem before. I don't have any scanners, looks like I'll have to call the hook and have it taken in

I thought for sure there'd be a mechanic or 3 here with an opinion at least

 

back up

it don't back up at all

no possible answers or even an idea as to what it may be before I call the hook?

no one??????????

 

I'm betting it's either a sensor problem or a valve body problem.... a problem that serious should have set a DTC... you can use the key method to pull the codes, then post them up here and we can help further.

There's a million and a half parts that could cause problems like this so it's hard to diagnose.

Does your 3500 have 4x4 or is it just 4x2? If it is 4x4 then try switching it into 4x4, if the transfercase functions and allows you to do it then it's likely a valve body or sensor problem. If it grinds and binds up then you've likely got some bigger mechanical problems going on that need attention.

I would also check out the rear differential and drive-shaft to make sure they have not been damaged.

 

Thanks for the reply Izero

Mine is a rear wheel drive 1 ton dually and driveline/rear end is in good shape.

Problem is I'm old and don't have any guages or devices to check readouts. What is the key method you speak of ?

I can swap motors out in my old Demon but I'm lost when it comes to this newfangled stuff.

Thanks again for replying Izero, much appreciated.

 

With the key in the off position and the doors closed turn the key in this sequence:

on-off-on-off-on-off-on then watch for any trouble codes that appear where the Odometer usually is. (Note: DO NOT START THE TRUCK)

They will look like Pxxxx where the x's are numbers, you may also get a Uxxxx if there is something else wrong but those are rare.

when it reads out the word "done" and the display goes blank you can turn the truck off.

Post up any codes you see and we can help troubleshoot further.

I would also suggest that you consider dropping the pan on the transmission to check the filters, next I would check the linkage on the top side of the transmission for wear/play or it might even be disconnected all together, which is a pretty easy fix... just a bit time consuming.

Hope that helps, post up what codes you get and let us know what you see under there.

 

finally got around to it as it's been on the back burner,

zero, I did the key test and the first readout other than the odometer reading was pdoNE

I think mebee I'll talk to the tranny shop tomorrow and line up a hook to come get it, seems to me it's something serious which is hard to believe with only 60K easy miles on it

never thought Mopar would let me down when it comes to a drivetrain but this tranny is none too impressive for a 1 ton dually

 

Yea the Gas Engines didn't come with a super beefy transmission like the Cummins models do....

I'm going to guess you either lost a gear, or possible lost a bearing on the output shaft.... They'll likely need to get the whole thing torn down, but they will prolly know what is going on when they get the transfercase/trans pan off...

Keep us posted, and hopefully the shop will take some pictures...