Rumble when deceleration

[Perspective]

My 06 Liberty auto with 241,000 miles just started making a new noise. It only occurs when I am decelerating and seems like it's about to downshift into 2nd and then again before going into 1st. When it gets close to down shifting into 1st, it also give a shake/shutter that you can feel. The sound is similar to engine braking in a manual.

Other than that, it seems to drive fine and shifts smoothly going up through the gears. This only occurs when slowing down.

Any thoughts? Would ****** mounts cause this? U joint? ****** going bad?

 

[KJowner]

Is there plenty of oil in the gearbox? Is it still nice and pink? If it's brown or black the clutch packs are slipping.
Start with the cheapest part after checking the oil, the front prop UJ, is the small rubber boot still in place? If not the joint is probably wrecked. You can completely remove the shaft for a test run, and the joint is cheap + easy to replace.

 

[Perspective]

So the gearbox oil is pink. The small boot coming out of the transmission on the drive shaft going to the transfer case is torn and there is definitely a little play. Looks like I'm starting there.

 

[Perspective]

UPDATE: I removed the front drive shaft and there was improvement. The sound is not as bad. The sounds come during deceleration at 55-45 and then again around 25. The vibration is really there anymore. It feels like there is a drag on the jeep and sounds like a faint engine braking.

The front driveshaft definitely has play on the transfer case/transmission side.

The only thing that may be related is I recently did the rear brakes and afterward, when slow moving in a parking lot, there would be a rubbing sound/metal sqeek. I even replace the sliders on the calipers as they were rusted/frozen up.

 

[KJowner]

A dragging brake will do it, any noticeable heat from them after a drive?

 

[Perspective]

A dragging brake will do it, any noticeable heat from them after a drive?

No visible heat last time I checked the wheels but I’ll pull the brakes apart and reassemble once North Carolina gets through this week’s heat wave. I was dismissing the brake thing since I had to replace the slider tubes and greased them up real good. I do remember the pads being really tight to get back on.

 

[Perspective]

After reading this thread, this sounds exactly like mine. I'm wondering it it's the rear u joints.

Vibration/ humming?????????

Last Friday my 06 Liberty began having a vibration from somewhere??? mainly occurs when deceleration and at almost all speed you can feel a slight vibration I had it on a lift and checked both wheel bearings. They are tight the noise/vibration couldn't be found while on the lift. "drove" in...

www.jeepkj.com

 

[Perspective]

After reading this thread, this sounds exactly like mine. I'm wondering it it's the rear u joints.

Vibration/ humming?????????

Last Friday my 06 Liberty began having a vibration from somewhere??? mainly occurs when deceleration and at almost all speed you can feel a slight vibration I had it on a lift and checked both wheel bearings. They are tight the noise/vibration couldn't be found while on the lift. "drove" in...

www.jeepkj.com

I just took mine for a spin and when I got back one of the four movement points on the rear most u joint was hot. I think u joints are my next replacement.

 

[KJowner]

What grease did you put on the slide pins? Mineral grease attacks the rubber parts makes them swell up, silicone grease only around brakes!

 

[Perspective]

What grease did you put on the slide pins? Mineral grease attacks the rubber parts makes them swell up, silicone grease only around brakes!

Silicone brake grease. I believe. Or the stuff that comes with the pads.

 

[Perspective]

Resolved: It was the u joints. They were shot. I had to rent a u joint puller because a hammer and docket wouldnt get them off and most of them actually broke apart using the too. Several were dry and one even had indentions where the bearing rods sat, likely, not moving. Also had a dragging parking brake but that wasn't the cause. Popped the pads off and will fix when it cools down. The jeep runs so smooth now. Headed to 300k miles now.

 

[blackhawk]

Resolved: It was the u joints. They were shot. I had to rent a u joint puller because a hammer and docket wouldnt get them off and most of them actually broke apart using the too. Several were dry and one even had indentions where the bearing rods sat, likely, not moving. Also had a dragging parking brake but that wasn't the cause. Popped the pads off and will fix when it cools down. The jeep runs so smooth now. Headed to 300k miles now.

The long drive shaft u joint?

 

[Perspective]

The long drive shaft u joint?

Yes, I replaced both ends of the driveshaft going to the rear end. I don’t know which one was the culprit for the sound and only one u joint cap was getting hot but only two of the wiggt caps came off like they were supposed to. The rest broke while removing.