Vibration from the rear when decellerating
On hwy, going some 60-70 mph, and then the car(s) in front of you slow down just a bit. Really just a bit. So you don't brake, there's no need to hit brakes. You just lift the gas-pedal-foot (right one, I presume) so the Jeep slows down, and then you go back normas as soon as everything else turns normal.
In the process, however, there's a vibration that comes from the back (ONLY from the back) when I lift my right foot slowly off the pedal. If I do it very quickly, the vibration comse, but is very very short. If I do it nice 'n easy, the vibration is a bit longer (about a second). If I use brakes to slow down, no matter how lightly (or heavily) I use them, there's no vibration. Also no vibration if I let go the gas pedal and press the clutch at the same time (i.e. I go "gearless") - no vibration.
I checked U-joints, but there's no play at them. Nada. Zip.
So I was thnking two things:
1. the vibration might have been there all the time, only I didn't notice it
2. the vibration could be normal. I let go of the gas, the engine starts to slow down but the rear wheels keep rolling, so at some point the wheels are rolling faster than the engine, so everything vibrates.
Could it be true, or is something gone bad?
Oh yeah, when I try that same gas-release thing in the city (30-40 mph) there is no vibrations whatsoever no matter what I do with gas/brakes/clutch.