I have been chasing what I thought was a front end-possibly cv vibration when reaching hiway speeds of 55 to 70. Come to find out It is directly related to engine RPM. The vibration begins at 1800 rpm no load, and continues on into rpm ranges of 2200 plus. There is no misfire data. no vibration upto the 1800 RPM. any suggestions would be helpful.

 

It could be either the torque converter or the harmonic balancer, with more emphasis on the TC.

 

how does one go about diagnostic on the torque converter?

 

TC shudder. Mine went away when I had my ECU upgraded via an Edge tune. Fully locked TC now (And 25HP+ with the tune).

 

I have been busy these last days, but today I got around to replacing the balancer. With no resolution. Can you explain in more detail what your issue was, and more detail of what your ultimate fix was. I am not familiar with what an Edge tune is. Did you have the ECU replaced or something else? Did you have vibration at mid range rpm regardless of load park and at hiway speeds?

 

My TC would shudder only at highway speeds (40-65 mph). After I had my stock ecu upgraded (programmed), my TC is fully locked and I haven't experienced any shudders issues since. The ECU tune upgrade required I only use 93+ octane otherwise I'll ping. This has been my experience with the TC shudder issue.

 

Then you are not sure if you had the vibration under no load static conditions such as in park with RPM up beyond 1800?

 

Sorry, mine did not.

 

I believe I have eliminated every possibility in my case except for three things. It has the possibility of being a flex plate issue, but I see no cracks or abnormalities looking through the inspection cover. Beyond that it could be a balance issue with the torque converter, or maybe the pump and or input shaft on the transmission. At this point after spending so much on all the other non-fixes, I am a bit hesitant to pony up the $1400 to get a new flex plate, torque convertor and pump put in. One could do each one at a time but if the first did not fix the problem, then the expense goes way up, better to do all three at one time. It will have to get much worse for me to consider this. But if it does be assured I will report my findings and or solution to the problem.