Hello all,
I've got a 2005 Liberty CRD with ~134k on it. I've got 2 sounds that I'd like to describe and see if you guys have any thoughts. I think the sounds will turn out to be related, but it's hard to say. I'll just present as much info and feedback as I can and we'll go from there....
First problem - everything sounds mostly fine around town, but when I hit the highway, somewhere around 65mph+ it feels like I am constantly going over small bumps - not as frequent as the grooves in the road, but constant thumping. Maybe 2-3 thumps per second and it varies with speed (subject to calibration of course
So I had it in the shop for a diff service a few weeks ago and asked the shop to take a look at it and they said tires. Hmmm.... Ok, so I took it to Discount Tire who put on new Hankook Dynapro ATM's last March and told them the story. They checked out the tires and rebalanced them all and said everything looked within spec. Took it back to mechanic for a hose replacement and told them that the tires were clear, please check driveline again, and AGAIN they told me that it was the tires and that they needed to be load tested. Ok, fine. Went BACK to D. Tires and they load tested them, swapped the front tires and did a road test with me. ...it's not the tires.Second sound - sometimes, when the Jeep is cold, when I start down the neighborhood street there's a pronounced thump from something underneath. The high speed thump is subtle, but noticeable, this thump sounds like someone is under the car hitting the chassis with a hammer. Scary? Yes. Here's the fun part - it goes away after ~1/2 mile driving. Also, the frequency is slow. Moving ~20mph the thump is maybe once per 1-2 sec. Certainly not in time with the tires on the road, hard to tell in terms of driveshaft rotation with the gearing of a given gear speed. Also, if it's doing this and shift into Neutral while moving, the thump continues.
Other notes - I'm definitely fighting the transmission fluid check valve issue, in that sometimes if I don't "prime" the fluid for long enough, when I put the car in Drive it just sits there. If I don't catch it back into Neutral in time, the gears "crash" and it stalls the motor. I'm more and more careful, but it's definitely crashed a few times. Related? Possibly. If I prime it up and it goes, the transmission shifts nicely and seems to be fine. Also, I've been underneath to see what I can see for myself and the driveshaft U-joints seem to be solid (though it's hard to know for sure). I did notice that if I move the rear drive shaft side to side with my hands, I can move the transfer case on the mounts enough that it taps the undercarriage somewhere. Hard to tell exactly, but that's what it feels like.
Any ideas where to start? Transmission issues? Transfer case? Joints? It's a lot to take in, so let me know if I can supply any further info. In general I'm diving around town and it hasn't been too bad, but I'm on the highway about once a week and I'm starting to get nervous taking it up to speed. Might be fine, might be really bad. =/
Thanks in advance for your feedback!
Chad
