Transmission Shudder _HELP!!

[MRay0324]

I have a 2003 SO CTD Quad cab with 48 RE transmission. If I am in OD (O/D not locked out with switch) and I accelerate at about 40 MPH my truck will get to about 50 mph and as it goes go into the final gear I will hear a shudder. Does anyone else have this issue? Could it be a line pressure issue or do you think it is the torque converter? This perplexes me since when it happens I am NOT towing anything. My truck has 2500 miles and this is very frustrating!!



Thanks!

Mark

 

[David Muench]

Happens to me on my 47RE. The truck is just shifting into OD too early and the RPM's are dropping so much that the drivetrain vibrates. IMHO, the auto trucks need work on their shift program for overdrive.

 

[MRay0324]

transmission shudder update

I took my truck to the Dodge dealer today and here is the scoop according to them. They say the shudder is coming from the passenger side front - where your right foot would be and they don't feel that it is a transmission issue as my check engine light or the transmission overheat light would light up and based where the sound is coming from. I have scheduled another appointment and they are going to hook up my truck with a device that can pin point where the sound is coming from with alligator clips to narrow down the issue. They say it could be the turbo wastegate, catalytic converter, baffle in the muffler, heat shield,etc. I hope this is the case as I was worried that I was frying my transmission every time it happened. What do you guys think? Is this feasible? If it is a transmission issue it could be that my transmission is binding - just my opinion.



Thanks!

Mark

 

[Steve M]

Mine does that too. Some one here said it was the waste gate chattering. The vibration noise doesn't really bother me as much as the fact that it locks up the TC just as I go to accelerate around 40mph. I wish I could have it programmed like my '01. 5 47RE was. It wouldn't go into O/D unless I let off the throttle completely or stayed on the throttle until about 65mph with 3. 54 ratio. Should be about 55mph with the 4. 10. My '03 will do this "if" I give it enough throttle from a launch. But if I take off easy and then need to get into it, there it bogs into O/D lockup at 40mph. Some people cried and a TSB was issued to "fix" the delayed O/D engagement in the '01. I never had mine fixed in the '01. 5. It was perfect tow mode all the time. While empty, if I wanted O/D I just lifted off the throttle for a second and there it was. But it never locked up just when I needed to accelerate.

 

[PCline]

MRay, I can almost guarantee it's the turbo wastegate. Does it only do it if there is a signifacant change in rpm's?



I notice you have the SO engine. It is more pronounced on the SO engines because of the lower power. The engine doesn't have the "get up" it needs to accelerate the truck and keep the rpm change to a reasonable level. The rpm change, while the engine us under load and consequently high boost, causes the wastegate to "flap" (I'm hoping someone will chime in with a more scientific explanation here).



My '96 12 valve used to do the same thing. In fact, if I was in 1st (with the shift lever) and accelerated to about 2200 rpm and then took my foot off the accelerator it would do it. I don't think an 03 will do it because the electronics won't let the engine spool down fast enough by itself, but you could try.

 

[sag2]

You might want to pull the silencer ring out of the turbo and see if it makes a difference. I pulled mine out to see what difference it made if any, and somehow my "Mr. Nobody" lost the snap ring that holds it in. So it looks like it is staying out. I have noticed the turbo does not "bark" as loud with it out when the trans locks up in fourth. Mine also had a vibration/drone when it locked up at slow (40) speed that sounded like a heat shield or the exhaust rattling. That seemed to go away, but maybe I just drive it a bit harder now.

If you notice, the lockup occurs a little too early for my liking, but there is no way to change it. If it really bothers you, leave the OD off until you get past about 45-50, and if that makes it go away it is most likely power train vibrations because of the low speed and load. At that point it is nothing to worry about.

 

[MRay0324]

Found the problem!

PCline,



You were right - it is the wastegate in the turbo causing this. I took my truck to another Dodge dealer and took the tech for a ride. He said that is what he thought it was and we would confirm when we got back to the dealer. He tried to duplicate it in neutral and park and the truck wouldn't allow him to do it. He then put it in reverse with the brakes on and revved up to 2200 rpms and let off the gas and the wastegate made the noise I have been hearing. I was standing right by the turbo with the hood up. I feel better that he confirmed it but wish we didn't have to put the wear on the drive train to verify. Oh well - nothing can do about it and I at least I now know for sure the cause of the noise. Thanks for your help!



Mark