birdnerd

Just like the title says. When I let off the gas at speed, 30+, there is a low hum. It's a 95 jgc, 4.0 auto, np249. The boots on the cv shafts need to be replaced. Could that be the source?

JDawg965

Can you specify where the hum is coming from right or left side? My guess is wheel or hub bearing. But with a bad cv boot the grease does not stay in the axle which will allow for a noise but usually it's a bearing.

johnbanghart

is the jeep all wheel drive , if so its kinda normal from what ive heard mine does it to but mines a v8 and awd...my buddy has a 4.0 jgc his does the same thing also

birdnerd

It's awd. Even after switching the trans speed sensor it still won't go into overdrive. But now I'm getting a code saying my battery voltage is low.

kjc

Well, it may not be causing the issues you're having, but a bad battery can cause several problems. I'd replace the battery first, if it's 3 or 4 years old it's about time. Check the alt. too.. a weak alt. can shorten battery life.
*Won't go into OD? Maybe that has something to do with the humming noise?

JDawg965

^^^^^^ yea deff replace the battery mine was going bad and my abs light came on, cel for fuel issue came up and the jeep ran horrible, replaced the battery all issues went away, so I know first hand that low voltage can cause weird issues especially in jeeps

johnbanghart

you didnt metion previously that you jeep wont kick into over drive??...does yours have the push button selector to turn it off cause if it does maby its stuck on or shorted out i think on mine when its OD is turned off its has a green light under the button