Okay , first of all this is a great site. I have been reading on here for a few weeks and there is a ton of great info on here.

Here is the problem. I have 2006 Dodge 3500 dually with the 5.9 and auto trans. I haul a 40 ft gooseneck trailer and usually with the weight of the trailer and load I am pulling around 16000-18000 lbs.
I was driving to pick up a load and at around 55-60 miles an hour I developed an intermittent shudder when I would apply throttle. It does not do it all the time. I stopped by a local transmission shop and without going for a ride or running any diagnostics or anything they told me that I need a new transmission and that they would not even bother rebuilding it. I have already replaced the gov. pressure sensor and solenoid. It shifts really nice no more of the 1-2 gear hunt. I adjusted the bands and replaced the filter. I put ATF+4 valvoline in it and still has the shudder right at the acceleration point from 55-60-65 then it's gone. This happens in tow/haul mode and in regular drive. It does this with or without the trailer on it and I just cannot believe that this truck with 125000 miles on it already has a trashed tranny. ANY suggestions at this point would be great as this truck is my livelihood.


Thanks in advance.

Aaron

 

Was there any metal in pan or fluid smell burnt when you serviced trans? If clutches were slipping fluid would have been dark and smell burnt. You checked the u-joints out already and center support bearing is good?

 

I checked the u-joints and carrier bearing. There was quite a bit of clutch material on the magnet and some very small metal flake which I am sure is not good. I think that I waited to long after I noticed the "shuttle shift" to change the gov. pressure solenoid and sensor. I was told by the tranny shop that the overdrive gear is more than likely the culprit and that is what is failing.

 

Also yes there was some dark fluid in the bottom of the pan when I took it off and it didnt look too good. Is it possible to just rebuild the overdrive unit of the transmission?
From what I understand it is a bolt on unit on the rear of the transmission. But, I have not looked at a manual yet so I may be wrong.

 

Until it is out and apart no one knows what is slipping!

It may be the converter clutch, the OD, or the front(3rd gear) clutches.
These trans are easy to rebuild--with experience-- and any trans shop that simply says replace it is not going to get my business.

Where are you located?

 

j-fox, that was my thought exactly. Without the transmission being out of the truck and apart you will not know what is slipping. I am in Cincinnati Ohio.

 

Intermittent and at that speed sure makes me think it's a u-joint. I had the exact same thing happen and I checked my u-joints and all seemed fine. I finally pulled the u-joints and one cup was bone dry and the bearings were dust. The other u-joint was just shot. (These are the two rear u-joints on my drive shaft)

What I think was happening was the joint would slip a bit while parked and then when I started it was out of balance. Next time I stopped at a light or whatever it would slip back into balance and it would be fine.

It got to the point where if it would shake I would stop and put the truck in neutral and start again. About 50% of the time I could get rid of the vibration. After a few thousand miles I couldn't get it to go away and even though the u-joints seemed fine, I took out the shaft and then saw they were toast.

So maybe your problem isn't as bad as you may think.... I'd check u-joints and the carrier bearing first. Heck, it could be the rear diff too. Or maybe you threw a weight on the drive shaft. But that wouldn't be intermittent.

Good luck.

 

If its a shudder that shakes the whole truck and only happens under acceleration, its the TC clutch slipping. Won't get better, only worse. You could upgrade the TC, add a shift kit and a few other parts and run until it dies. It might run a long time with those upgrades if your not thrashing it.

Don't rely on any old trans shop to have a valid opinion or even a clue how these diesel units function and what they need. Most of the struggle to understand how to make one work behind a little 4 banger gasser. They make money on selling rebuilds, mostly inferior ones, not fixing the real issues.

At 125k and having been worked that hard I'd say you got a good one. If it was bad it would have crapped out a 30k. The stock transmission has a finite lifetime if you use it hard. Thats the way they are built, get used to it cuz every single one on the road is the same way.

A few upgrades at the outset and you have an outstanding unit. Just gotta get to it before the Cummins TQ does.

 

My truck was doing the same when i ran downloader on higher setting than tow/haul. I also found that i had a small hole in my fuel return line(not sure if the hole had anything to do with it or not) but since I replaced both return and supply line and now run just on tow/haul mode the shudder under acceleration went away.

 

well, since I don't have enough money or time right now to rebuild the transmission while I have it out I am going to put a torque converter in it and hope that it will fix this problem and last me a little longer. I need to save a little more money for either a rebuild or a built tranny. Well I will let you guys know how this turns out.

 

Ok guys, mines acting up, but slightly different actions. Without the 5ver, the vibration is very minimal, almost non existent. With the 5ver, over 40mph, the vibration is again minimal. Under 40mph with the 5ver, while accelerating, it'll shake your teeth out, and you can hear something knocking from the rear of the cab, underneath. The u-joints appear to be good, no slop, the carrier bearing has very minimal play when moved by hand, but is fully intact. Just for shiggles, I checked for codes, and came up with P0700, Which says "transaxle control module". Any ideas?

 

Is this with the converter locked or unlocked?

If the TC is unlocke dit is likely the center support bearing in the rear drive shaft and\or axle wrapup. Shocks good? Center bearing support have minimal movement?

 

The TC locks up around 40mph. The tow/haul button, makes no difference. Towing at 65mph ( the most I'll go) the vibration is still there, but very minimal, you can just barely feel it. The minimal movement in the support bearing, is less than 1/16" between the driveshaft, and support bearing. The rubber in the SB, is all intact. I am checking out the options of either replacing the support bearing ( $52), or going with a one piece drive shaft ($?), if that is the general consensus of the vibe. BTW, the truck has 186k miles on it.

 

The TH button is just an OD On\Off switch. It normally does not effect the lockup routines.

When the bad shake happens is the TC locked or unlocked? Thats the most important fact. Depending on how hard you are into the throttle and the load sensed, the lockup speed will vary.

If the shaking happens when rolling into the throttle with the TC locked but doesn't happen when the TC is unlocked, the likely problem is the TC.

If you are getting shake\shudder irregardless of TC lock it is more likely a driveline problem. A bad TC will also cause shake and vibration under load when unlocked so it can get hard to tell exactly where the issue is.

You cannot check the ujoints for these vibrations uless you take them out and pull the caps. The joint will feel good, have no slop, etc, yet be dray and you WILL have vibrations at any time. Most notably launch shudder but it will show thru the rpm band. If you have not changed them in 50-70k range, change them.

The center support bearing is a pain. The TQ will cause major deflection in it even though by hand it feels good. Put a bar behind the drive shaft for some leverage and see how far you can move it. My guess is you can deflect it or an inch all ways.

The only fix for that problem, and a lot of the vibration issues, is a one piece drive shaft. Without the center support to deflect under TQ you would be surprised how launch and drive vibrations diminish.

 

Thanks for the info. I really don't get hard on the pedal, since this is an auto behind the HO motor. I would have to say it's worse before the TC locks up, it's always there, just worse with the added weight of the 5ver. I will look into replacing the ujoints, but where is a decent place to get the one piece, without selling my daughter, to pay for it?