Rumble noise when going up hills

[ky_man]

I own an '06 KJ w/4WD, purchased in October. Has 30K miles, looks brand new.

I have two questions, somewhat related:

When driving up a hill the other day (fairly steep ~4-5% grade) at ~35 MPH I noticed a weird rumble sound, kind of like driving over tiny rumble strips. Faded in and out, kind of a uRRR..uRR...uRR sound. Since that time, I have noticed the noise sporadically driving up similar sized hills (not every hill gives me the noise). I only hear the noise going up hills, not down or on the flats. There is always some type of rumble noise coming from the rear part of the Jeep when going under 35MPH, but this is normal as I hear this in many SUV's....the rumble I'm referring to is much more noticeable.

Question: Any idea why I am hearing this sound? Torque converter slipping?

Another thing: When I start the Jeep and shift into reverse, it kind of 'clunks' and when I go from reverse to drive, it seems to take longer than it should to engage.

Question: Is this normal?

Everything else seems fine. ****** shifts great when driving, real smooth.

Thanks!

 

[JeepJeepster]

Do you feel a vibration when you hear this noise?

The lag from R to D is fairly normal when its cold.

 

[J-Thompson]

Do you feel a vibration when you hear this noise?

The lag from R to D is fairly normal when its cold.

also
what RPM are you turning when it "rumbles"
lower RPM will work the Jeep harder than say 3000 rpm or more

 

[jnaut]

I own an '06 KJ w/4WD, purchased in October. Has 30K miles, looks brand new.


Another thing: When I start the Jeep and shift into reverse, it kind of 'clunks' and when I go from reverse to drive, it seems to take longer than it should to engage.


Thanks!

Speaking to this-- normal. The 42rle is... klunky. I have one. But it works. There's also a specific blurb in the manual about trans fluid draining when the car has sat idle, and actually may not readily drop into reverse right away.

 

[ChiefRudy]

MY Jeep does the "rumble noise" every now and then too. Sounds like it comes from the front. At low speeds between 20-35MPH and with RPMs around 1600-2000. It's done the noise ever since I got it. Does it more often when the engine is cold compared to warm. I've had it happen both on a small grades and even straight road. I don't recall any vibrations...

When I drive it tomorrow I'll watch my RPM's and speed so I can precise Numbers.

 

[flair1111]

its just the ****** and how it is. weak. i have reverted to just starting out with it in 2nd and then manually shifting to 3rd (drive) when the speed hits no less than 37mph or around 2700rpms. this ensures every time that the rumble you hear doesnt happen and IMO saves the ****** from horrible wear.
From what i can gather, our trannys (unless you floor it) shifts into 3rd way to early and doesnt want to downshift back to second until its too late.

the low rpms and load i think causes the T-Converter to vibrate, or something like that.

mine also shifts into 4th(overdrive) way to early and does the same thing if im not careful. i have learned to just drive it like this...

1. start with shifter in 2nd.
2 after second gear runs into 2700rpms or 37mph, shift into drive.
3. depending on the situation of the road i will be driving, i may also leave OD off and not use it unless speed increases to over 60mph in drive (3rd only)...then ill use the over drive.


its a pain sometimes, but it takes care of the shudder and noise.

 

[wagonbldr]

Hey Ya'll. I'm new here. Just got an 03 Liberty Sport 4X4, with auto trans. It also has a weird rumble/vibration that starts at about 47mph and goes away at about 57mph. I have switched the tires around and have looked, and shook the drive shaft looking for loose u joints. Is this just a normal thing with the automatics? It is most noticeable when under a light to medium load.

 

[Powerslave]

Mine does it too, it only does it when the torque converter locks up at low speeds like that. WIth O/D off, it happens to me all the time, this thing has the TQC lock up at 35Mph going up a hill... I get the rumbling too at this point... Can these be reprogrammed to have the TQC lockup at a higher speed?

I may hook up a TQC lockout witch... It's pretty easy, I did this with my Geo Tracker, it locked up too fast as well...

 

[Ry' N Jen]

We must have a special KJ or something, but with 177000 Kilometers on the clock our Rig just hums along full time!
No strange sounds or vibrations, no crack rattle pop!
Just effortless motoring everyday!
Our Liberty must have been built mid week by Chrysler employees who were paid well, no employer gripes, and got laid everyday of the week!
I mean, this Truck just keeps on going and going like the Energizer Bunny!
I have been taking stuff apart just to inspect all mechanical parts to see if anything is out of the ordinary and all Is well!

Damn I love this Jeep!
Best vehicle I have ever owned!

(Cheers)

 

[JeepJeepster]

I may hook up a TQC lockout witch... It's pretty easy, I did this with my Geo Tracker, it locked up too fast as well...

Elaborate..

 

[goob2k]

Hey Ya'll. I'm new here. Just got an 03 Liberty Sport 4X4, with auto trans. It also has a weird rumble/vibration that starts at about 47mph and goes away at about 57mph. I have switched the tires around and have looked, and shook the drive shaft looking for loose u joints. Is this just a normal thing with the automatics? It is most noticeable when under a light to medium load.

Mine did that in addition to the steering wheel shaking as I slowed down. It turns out that the u-joints weren't loose but seized up. I got them replaced and I no longer have the 45-55mph vibration.

I've been noticing the faint vibration going up hills too. It seems more noticeable if I'm turning slightly while going uphill.

 

[Powerslave]

Elaborate..

The lockup TQC, you know what that is right? The torque converter locks up for a 1:1 communication with the engine.

There is a signal wire that engages the lockup solenoid, that locks up the TQC. So, I spliced a switch into the line, so that there was no lockup, till I turned it on. I also installed a light that came on when lockup was available. It would not come on till warmed up; and, when using a steep gas pedal, if you press down too far where lockup would disengage, the light went out.

With the TQC lockup interrupt, the TQC clutch would not engage unless the switch was on. IT does not hurt anything, because a lockup clutch CAN burn out, and not work at all. As far as the ECM is concerned, the lockup signal is sent, and the solenoid line latched to engage lockup.

Burnout? Yeah, this happened to me with that Tracker, TWICE, and was a 1200.00 job each time if not under warranty. IT went out at 12k miles, then again at 35k miles (crappy TH180 Transmissions). The thing was sensitive at times, popping in and out of lockup at 45Mph, which may be why it burned out prematurely. SO, with the switch, I had control over the TQC lockup clutch, it lasted till I sold it at 98k miles. I had so many switches, buttons, and lights, that the person that bought it would have NO CLUE...

For the hell of it, I also installed a HARD engage, so it would lock up in any gear I wanted. It's just supplying voltage to the lockup solenoid. If idling, and you forced a lockup, the thing would stall, of course... I rarely used it, but it was there.

Wait till you hear about my Smoke Screen device... Heh heh heh...

 

[JeepJeepster]

Thats pretty neat... The T/C does lock up way to early in the kj but its all for gas mileage.. It being unlocked more causes more heat also..

Personally I just lock out O/D whenever Im not going to be going over 45mph or so for awhile. Actually I just lock it out when ever I get in my Jeep. Its like buckling my seat belt..

Also, I found out one time if you lightly press the pedal just enough to make the brake lights come on, the T/C will unlock..

 

[Powerslave]

Yeah, there is also a signal line at the break switch, that tells the ECM to release lockup. You can hook up a SPST switch there, so that when it is when ON, the ECM the break is depressed, and releases lockup, which is probably all that signal line is for. There are a few ways to do it...

I also leave O/D off under 45, but it still locks up at 35MPH when going up hills, and then it just boggs out, and downshifts all together, which is more wear and tear on the drivetrain all together, IMO. So, if lockup was disabled till 45, it would be fine... So, I will be installing my bypass when I get the chance...

If I were REALLY wanting to get all into it, I would use a circuit to not allow lockup till O/D was enabled, which is also kind of easy, just a relay hooked in with the other side of the O/D button wire that supplies voltage to the dash indicator. SO, when O/D is OFF, there will be no lockup...

 

[JeepJeepster]

Yea, Ive noticed it locks up even sooner with O/D off also.. If youre towing it doesnt do that since you will be giving it more gas to get to where youre going. I assume it wants to lock sooner with O/D off to reduce heat while towing.

It seems to unlock the torque a little late going up hills while towing if you are not really pushing it. There is a fine line between it unlocking in 3rd and just downshifting to 2nd.. I try to keep the downshifts to a minimum while towing but sometimes you just cant help it.

 

[Powerslave]

The computers are programmed to partially lock up the TQC clutch as well, but that's a lot of slippage and clutch friction. I am just going to install the switch, a push button with a built in light. So, the switch light comes on when Lockup is available, then I can push it to engage... It is easy for me, I do a lot of electronic work, wiring and so on, and I have done this exact thing before. I just need the TCM wires, so I will look for a TCM pinout when ready.

On my Motorcycle, the C50t, ALL my windshield bolts are license plate fastener LEDs.. White along the top, with one green where it goes down, and two greens below that. All the top lights are on with the headlamp. The others (two on each side) that go downward blink with the turn signals on that side... Pretty neat. I use resistors on all my LED installs, so the LEDs last. 330ohm for single, but I have all the tops on a 60ohm, and each set of signal LEDs on a 120ohm. When LEDs get hot, they draw more current, so you need to limit the current they can have, as they do tend to blow themselves out because of this.