Final Report - Thank you for all of the great advice.
PROBLEM SUMMARY
I experienced a driveline vibration after installing a 2" lift in my otherwise stock 2005 TJ Sport. I was hung-up on pinion angles and output shaft angles and trying to sort out a solution to my annoying and potentially damaging vibration when accelerating while driving on the road.
SUMMARY OF ADVICE
For my minimal lift, don't get hung-up on precise measurement of angles and do not try to change the rear differential pinion angle - which is exactly the direction I was heading prior to seeking advice on this TJ forum. My options were to install a slip yoke eliminator (SYE), lower the transfer case (TC), or raise the engine with raised motor mounts. Basically, since you should not change the rear differential pinion angle you have to change the TC output shaft angle by lowering the TC or raising the engine,
WHAT I DID
Even though I did not want to defeat the purpose of my 2" lift and lower my transfer case permanently, I installed a 1" pile of washers between the frame and TC mount plate (lowered the transfer case 1") to prove that it was my problem. Lowering the TC worked and my post-lift vibration was gone. Not wanting to have a lower TC I ordered and installed the 1" motor mount lift (MML). With the MML installed I was able to remove my transfer case lowering washers. I did not remeasure my pinion angles. I'm over it and don't care about it anymore - thanks Jerry. I have since driven the TJ on and off-road and have not experienced any issues with vibration. Problem fixed!
1. Are my pinion angles ideal thereby preserving the longevity of my driveline moving parts? Time will tell but I will monitor U-joints for excessive play and otherwise, not worry about it.
2. MML does require raising the fan shroud about 1/2" - 1". Some folks say to elongate the shroud mount holes but I could not do that as there is a plastic gusset where I needed to elongate. Instead, I used four self tapping screws and screwed the shroud to the sheet metal it mounts to after raising the shroud. It can always be repositioned to its original location if the MML is removed.
I hope that documenting this adventure will help someone in the future.
PROBLEM SUMMARY
I experienced a driveline vibration after installing a 2" lift in my otherwise stock 2005 TJ Sport. I was hung-up on pinion angles and output shaft angles and trying to sort out a solution to my annoying and potentially damaging vibration when accelerating while driving on the road.
SUMMARY OF ADVICE
For my minimal lift, don't get hung-up on precise measurement of angles and do not try to change the rear differential pinion angle - which is exactly the direction I was heading prior to seeking advice on this TJ forum. My options were to install a slip yoke eliminator (SYE), lower the transfer case (TC), or raise the engine with raised motor mounts. Basically, since you should not change the rear differential pinion angle you have to change the TC output shaft angle by lowering the TC or raising the engine,
WHAT I DID
Even though I did not want to defeat the purpose of my 2" lift and lower my transfer case permanently, I installed a 1" pile of washers between the frame and TC mount plate (lowered the transfer case 1") to prove that it was my problem. Lowering the TC worked and my post-lift vibration was gone. Not wanting to have a lower TC I ordered and installed the 1" motor mount lift (MML). With the MML installed I was able to remove my transfer case lowering washers. I did not remeasure my pinion angles. I'm over it and don't care about it anymore - thanks Jerry. I have since driven the TJ on and off-road and have not experienced any issues with vibration. Problem fixed!
1. Are my pinion angles ideal thereby preserving the longevity of my driveline moving parts? Time will tell but I will monitor U-joints for excessive play and otherwise, not worry about it.
2. MML does require raising the fan shroud about 1/2" - 1". Some folks say to elongate the shroud mount holes but I could not do that as there is a plastic gusset where I needed to elongate. Instead, I used four self tapping screws and screwed the shroud to the sheet metal it mounts to after raising the shroud. It can always be repositioned to its original location if the MML is removed.
I hope that documenting this adventure will help someone in the future.
