My Jeep does a few weird things.

Hi all, hopefully I'm posting this in the right place. New user here.

I have an '07 Liberty 4wd with around 56k miles on it. I got it used with 53k miles on it so I have not had it long.

I have a few questions about it:

*The rear whines when I reach 50-55mph or higher. It sounds like rear gear whine, but I'm not sure. It gets pretty darn loud sometimes, I'd say it peaks around 60-65mph, and maybe higher when on the interstate. Is this normal?

*When going around 45-50mph in overdrive, the car makes a strange sound, kind of like a "groan" that comes and goes rhythmically. It's really hard to describe. If I take it out of overdrive it won't make the noise at the same speed, so I don't think it's out-of-balance tires (plus it drives smooth). It seems to be either an exhaust note reverberating under stress in that gear, or something. Is this normal?

*My speedometer is off. If I put it on 65, I'm really only going around 60-61. What would cause this? The car has normal size wheels/tires on it as far as I know. I can measure my speed with a GPS that matches other cars speedometers, and also when I come up against "Your speed" radar signs at schools, etc. I've done this numerous times now so I'm certain the speedometer is off by a good 4-5mph at that speed. Any idea how or why this would occur?

*The car shifts really hard from first to second if I go WOT or close to WOT. Is this normal? It's a really hard "jerk" from gear 1 to 2. 2 to 3 doesn't seem to do it. I had a Mustang GT and it didn't shift that hard, and it was a hard shifter (auto).

I think that's all for now. I really love the vehicle and it drives great besides this stuff. I don't know if I should take it into a shop regarding these things or not.

Thanks for any input!

*The rear whines when I reach 50-55mph or higher. It sounds like rear gear whine, but I'm not sure. It gets pretty darn loud sometimes, I'd say it peaks around 60-65mph, and maybe higher when on the interstate. Is this normal?

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sounds like rear diff sounds.. might need serviced

*When going around 45-50mph in overdrive, the car makes a strange sound, kind of like a "groan" that comes and goes rhythmically. It's really hard to describe. If I take it out of overdrive it won't make the noise at the same speed, so I don't think it's out-of-balance tires (plus it drives smooth). It seems to be either an exhaust note reverberating under stress in that gear, or something. Is this normal?

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id be concerned that its a U joint or a Bearing.. again id have the rear end looked at. no this is not normal.

*The car shifts really hard from first to second if I go WOT or close to WOT. Is this normal? It's a really hard "jerk" from gear 1 to 2. 2 to 3 doesn't seem to do it. I had a Mustang GT and it didn't shift that hard, and it was a hard shifter (auto).

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this also isnt good. indicates issues with the ******.

IMHO you seriously need to get this vehicle into a shop.

Change the rear diff fluid and go from there. While you're at it, change the front too. If you feel adventurous, take out the rear drive shaft and check the u-joints. I only have 42K on mine and I think the u-joints are starting to give me problems.

oh and find out if you have trac-lok or not. if you do have trac-lok you need friction modifier. There is a tag on the right side of the axel just before the end that will say either trac-lok or open. if it says open you don't need the friction modifier. Whether you have trac-lok or not may tell us if that may causing the whine too.

When I had bought my KJ it made the whining noise as well. I changed the fluid and put synthetic fluid in it's place. No whining anymore.

Weird huh? The only weird thing my KJ does is give me a chubby once in a while. And I don't even consider that weird anymore.

That said, service the diffs and go from there.

ptsb5a said:

Weird huh? The only weird thing my KJ does is give me a chubby once in a while. And I don't even consider that weird anymore.

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Yeah, but the rest of us do!

With regard to question 1, that whine sounds like when mine had a rear drive shaft u-joint going out. Not sure about the others!

Hey Dave, I stuffed the OME790s, OME948s and new shocks under the KJ last weekend. Unsagged the front end by about 2 inches. If your KJ was like my KJ, it'd give you a chubby on occasion too. Damn sexy beast.

For the 1st one, start bye getting your diff fluid changed, better to do it your self so you can check the c-clips and make sure one of the hasn't slipped out and grinding the diff case.

There is a TSB for the 2nd one, light throttle groan or hum around 40-45mph, they can reprogram the computer to change the torque converter lockup and something with 1-2 and 2-3 shifts.

Service Bulletin Number : 2100207
NHTSA Item Number : 10021089

3rd) My 06's speedo is also off, I figure bye about 8%, I've heard the dealer can reprogram it, and I've also heard they can't on 06+ so I dunno, you'll have to stop bye and ask them.

The 4th one might also be fixed bye the tsb for the 2nd one? Also make sure your transmission fluid is in good shape, and at the correct level.

ptsb5a said:

Hey Dave, I stuffed the OME790s, OME948s and new shocks under the KJ last weekend. Unsagged the front end by about 2 inches. If your KJ was like my KJ, it'd give you a chubby on occasion too. Damn sexy beast.

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Yeah she's pretty sexy... but still... lol... just playin!

If you haven't done them already, I would change your rear driveshaft's U-joints, your front and rear diff fluids, and at least a transmission filter. While you're doing ******, might as well drain and fill the transfer case. I think the U-joints could be your roar.

I have the same 50 mph rumble that lasts for about 4 mph and is accentuated while accellerating, as have several others I've heard from. I'm pretty sure someone said they had that for a loooong time with no issue, just watch to see if it is getting worse. I never noticed mine til I lifted, and weighing down the rear to compress the lift a little seems to cut down the rumble some. I assume it is due to driveshaft angle. After 6 months of that, I started getting a roar at all speeds, and after driving for 15 minutes and roaring real good, I got out and felt the U-joints. The rear was hot, and the front was not, so I changed both and the roar went away. 50 mph rumble still there though.

As far as the spedo being off, I think thats normal. I went up in size on my tires by about 1/2" diameter and then got my first check on the spedo with a GPS, and it was still about 1 mph fast. Now with my slightly bigger tires it is about 2% slow. I believe you can get this recalibrated somehow if you want to.

Thanks a lot for all the comments. The jeep seems to drive fine, it's really just the noises that I am not sure of. I'm not a mechanic in the least, so I will need to take it to a shop sometime and see what they can do.

I just spoke with someone at a shop and they said it's not common for it to whine in the back, and that I should bring it in for them to look over. I'll do that hopefully sometime at the end of this week.

As I said, it drives great and I don't have any "feel" problems with it, just noise. Hopefully it's as easy as replacing some fluids/lubricants.

So the 1-2 shift is not a hard shift for you guys when you floor it? I'm not sure if that's just the Jeep movin' out, or if it's a problem.

expect rear fluid change and maybe ujoint

dont accept diff replacement or anything crazy!!

get second opinion

I thought I posted a response, but I'm not seeing it for some reason.

Anyway, I called a local Jeep shop and they are going to look at it the end of this week. I have a few things that happen with it that I'm going to ask them to look into:

*Rear end whine.
*Pulsating "roar" (if you can call it that) at 45 or so.
*Speedometer being wrong.
*Gas tank blows gas out when it fills all the way.

That last one I get around by just slowing to about half speed when filling. It's the only car I've had spew gas back out when it gets full.

Hopefully they can at least take care of the major problems. Thankfully I have an extended warranty! Shouldn't cost me more than $100 to get stuff fixed.

Where is a good, official site to find TSB's on my Jeep?

*Now I see that my post just went to a second page. Duh!*

Go to Jeep's website and put in your VIN. it will give you any missed recalls and TSBs.

Also, the only *real* problem ThunderbirdJunkie sees is you keep talking about your car on a Jeep site
The only "car" ThunderbirdJunkie has is a 1994 Toyota Paseo. His Jeep is a Jeep

In all seriousness, you can't go into owning your Jeep with the mindset that it is just a car. It is a high performance machine, like a Ferrari or a Lamborghini, built for a purpose. It, like a Ferrari or Lamborghini, is a bad-ass vehicle for that purpose (which is going off road, rather than going fast, like the Ferrari/Lamborghini) and as a result, it doesn't act like other vehicles that are considered to be in its class (like the Ford Escape, Honda CRV, etc) because they are boring transportation boxes and not bad-ass high performance machines, just as a Ferrari F430 is not in the same class, and would not be considered "as refined", as something like a Mercedes Benz SL600, despite costing about the same and being in the same "class". It's a gutteral, gritty machine with what people that want a CAR would call faults.

Hopefully ThunderbirdJunkie explained why you shouldn't call your Jeep a "car" in a satisfactory manner Also, the only people that have chronic issues out of their Jeeps are the ones that call them cars.
(ms5490renegade, ThunderbirdJunkie is looking in your direction)

*The rear whines when I reach 50-55mph or higher. It sounds like rear gear whine, but I'm not sure. It gets pretty darn loud sometimes, I'd say it peaks around 60-65mph, and maybe higher when on the interstate. Is this normal?

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Could be a pinion bearing in the rear diff. Not cheap, but as said above, change diff fluid and go from there.

*My speedometer is off. If I put it on 65, I'm really only going around 60-61. What would cause this? The car has normal size wheels/tires on it as far as I know.

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Get the tire size and tell us. Even 'normal tires' such as OEM Optional size of 235/70-r16 will require the speedo to need recalibration through the "pinion factor".

An 07 wounldn't have Trac Lock...

HoosierJeeper said:

An 07 wounldn't have Trac Lock...

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To whom are you responding?

Speedo error is almost always tires. What brand/model and size of tires do you have? Some of the road noises can also be the tires, some are just louder than others!!

Other than that if its never been done, fluid and filter in ******, new fluid in front and rear diffs, new fluid in transfer case.

That reminds me i got to get some time this next month to do my diffs and transfer case.

My tire sizes, if I wrote this down right, are:

P225/75/R16

I assumed that was the stock size, but I could be wrong. I didn't look it up yet!

I would have guessed the speedo was off due to tire size also. Since I got the vehicle used, it might be possible that I have different tires on it than the original. My tires are really nice though, so I like 'em. They were brand new on the vehicle when I got it. Still had the little flippy things sticking out all over 'em.

They are Goodyear Wrangler tires.

It looks like that is the stock tire size after all, according to discounttire.com.

I'm wondering if it's possible my Jeep has had a "tune", like with a Diablo tuner or something like that. I know they'll do things like allow for harder shifts, speedo calibration for gears, etc.

No way to know if I have stock rear gears or what either, since it is used. For all I know it's got a lower ratio in there than stock and the speedo is off because of it.

Something else that makes me think it *might* have a custom tune is the hard shift from 1 to 2, and also it really "hangs on" to a rev even if I don't push the gas in that much. For example, if I push the gas halfway in, the Jeep will really drop and run, something I wouldn't expect it to do so much since I'm not going near WOT yet. But it really takes off. Could just be a Jeep thing.

Anyway, I guess the Jeep dealer will tell me something hopefully tomorrow. I'm taking the car in the morning most likely to have them look at:

*Rear whine
*Speedo being off
*Gas tank spurts when filling to full at the pump

I've read they'll replace the gas tank because of that last one, but we'll see.