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Discussion Starter #1
2010 Ram 2500 CCLB 4x4 Auto 2" Thuren Level 285/75R17 (33.9") Tires DRD 30 HP Tune 3.73 Gears 130,000 miles

Truck did not tow for the first 120,000 miles, tows occasionally now 5000lbs to 12,000lbs

Recent fluid and filter change in the transmission and fresh rear driveshaft ujoints

Symptoms

60-65 mph 1500 rpm 6th gear when you encounter a hill and press the pedal to maintain speed the truck makes a rumble/vibration (exactly like driving on a rumble strip) noise. The noise goes away immediately once the truck down shifts to 5th, but it takes a significant amount of pedal press to get it to downshift. The noise is more noticeable when towing or when in cruise control.

I have read all of the other threads that discuss the rumble strip noise and the consensus seems to be TC slip. I can not find a thread with a solution to the problem. Someone even said the noise continued after a new TC was installed. Others say to manually downshift to 5th (which I get) but I live in Colorado with a lot of hills and I didn't buy and automatic transmission to constantly downshift manually. When I tow I leave the shift selector in 5th and use tow/haul.

So here are my questions and I hope @TransEngineer and others will chime in.
  • What controls a 6th to 5th downshift? Can this be worn causing a delay on the downshift?
  • Could a bad TPS delay a downshift?
  • I am guessing an upgraded valve body and TCM tune would be a band aid?
  • Has this rumble caused damage?
  • Should I plan on buying a new transmission in the near future?
Thank you in advance for your help
 

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Do you have a scanner and have you been watching any live readings? TC slip and so on... Did the just start happening or was there a change you did?
 

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Discussion Starter #3 (Edited)
Do you have a scanner and have you been watching any live readings? TC slip and so on... Did the just start happening or was there a change you did?
I have AlfaOBD but I have not watched any live readings. Looks like the only options I have are requested and actual line pressure but I'll keep digging for TC slip.... Update... looks like I can read TC slip on my MM3... I will report back

As for my most recent change I installed a new stock turbo and actuator. I first noticed the noise after this install while I was towing my skidsteer around town. My first thought was I reinstalled the exhaust incorrectly and it was rubbing the frame. After removing to the exhaust twice looking for rubbing I am confident the noise is not the exhaust hitting the frame.
 

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I had this problem on my truck when towing on grades. I took my trans out and rebuilt it myself. I did everything during the rebuild so I couldn't say forsure if it was the converter clutch slipping or what it was but my shudder is gone. I will say that before I rebuilt the trans I took the valve body out and installed the BD protect 68 and that seemed to help with the shudder (increased line pressure).
 

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Discussion Starter #5
So I monitored some of the tranny parameters. Here are the results while the truck was making the noise

TC Slip was 0
Commanded pressure was 170
Actual pressure was 155 to 160

These numbers seem to all be in spec so now I am unsure this noise is the torque converter
 
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