Engine/Transmission (1998.5 - 2002) 1999 Shudder

[JNixon]

I have a newly rebuit transmission (15000 miles decof 04)that shudders when under load pulling trailers between 45 and 65 MPh with light throttle. If you cause a downshift the shudder goes away... Transmission shop is trying to say not their problem that I need to replace the APPS. I have no codes set and the APPs has been reset... ...

Any Ideas???

Thanks

 

[rkressg]

Did they replace the torque converter when they did the rebuild?

Could the bands in the transmission need adjusted?



I do not own an auto but those are the first things that come to my mind with those symptoms.

 

[Dual EE]

Here is some info from the DTT web site;

http://www.dieseltrans.com/phpBB/viewtopic.php?t=5



A torque converter shudder is a symptom not a cause. You need to find out what is causing the shudder first before you start throwing parts and money at it.



There are several things that can cause TC shudder, injectors, pump timing, and even transmission oil. I would say that about 80 % of lthe TC shudder i have personally diagnosed have been ATF oil related. I have also seen injectors cause shudder and in the 24 valve cases the fueling boxes & timing combinations have even caused shudder.



When a TC shudders it is a simple case of the dampner springs within the TC opening and closing. As they are opening and closing there is not enough hp to keep the springs collapsed and too much power to keep the springs (open) for lack of a better term. If your engine is not running smoothly it can also cause a TC shudder.

 

[BillGotthelf]

My money is on the TC and not enough fluid pressure to completely lock it up. Could be electrical interference in the TPS line to the ECM-PCM-Trans or valve body/pump not getting the pressure there.