geordi wrote:
Alignment front and rear, worn out suspension bushings and balljoints front and rear, inflation pressure and type of tires, long time since tires rotated and rebalanced, factory shocks and spings worn out, bad CV joints front driveshaft, bad bearings rear diff.
All of above on mine. Afterwards, averaged 34.5 MPG on a 3 hour straight run from San Antonio to Hillsboro TX along I-35 on Wally World D2 on Aug 10th.
With all that wrong... How noisy was your CRD before getting it fixed?[/quote]
Only real noise was from the rear diff - started out faintly at highway speeds in January, got progressively louder as time went on - sounded like a tire out of round - all the other stuff was found tracking down and eliminating the noise that turned out to be the rear diff.
First shop that checked my alignment and suspension said everything was fine. Month later had them rotate and rebalance the Coopers - noticed that the tires that had been on the front were losing CHUNKS of tread along the outer one inch, and had required 6 inch long weights to get them to balance. Took it to another shop that was highly recommended locally - exact words out of the guy's mouth - "That other shop may have CHECKED the alignment, but they sure as hell didn't ADJUST anything - it was WAY off". Immediate difference in the way it drove and handled, immediate increase in fuel economy on the first tank, without anything else being done.
Still had the noise. Replaced the now-much-abused Coopers with a set of Michelin LTX MS2's. Took FOUR TRIES to get them balanced properly, because the kids at the one tire chain store, IMHO, just didn't GAS. Finally went to a Firestone dealer, gent there took half an hour, said the other place had the weights off by 1/2 to 1 full ounce on all four tires. Rode beautifully after that - but still had the noise.
Next looked at shocks and suspension. Could already tell the stock shocks and struts were way past needing replaccement, and from reading on other forums, suspected that the ball joint and bushings on the rear upper suspension arm were worn out, and causing a "sound short" directly from the rear diff to the cabin - IOW, I was hearing amplified normal gear noise from the rear diff. Replaced the shocks and struts with a set of Monroe quickstrut assemblies on the front, and Monroe shocks on the rear - gained at least a 1/2 inch in ride height, and it sits level from driver to passenger side now. Ball joint that attached to the rear diff on the upper suspension arm was worn out, just installed a completely new suspension arm. Also replaced the rubber bushings where the front struts attach to the lower arms - rubber was actually getting beaten out of them. Big improvement in handling - can now take the same corners and curves 10 to 15 mph faster than before, and the beast doesn't feel as if it will topple over. But still had that darn noise.
Removed the driveshaft to the front diff. One of the CV joints was dried out and quite stiff. Left it out pending rebuilding the CV joints. Still had the noise.
Had the brake pads replaced with Bendix ceramics and all four rotors turned, as gent that had redone the alignment had noticed the rear pads were getting low. Nice improvement in braking and rotors look like they should after some service. But still the noise.
Finally got a bearing kit and went to a reputable axle/diff shop to get the rear diff checked out - pinion seal had started weeping oil, for the SECOND time since new. Young gent found that the drivers side carrier bearing was shot - the gears nearly fell out in his hands when he pulled the cover off. They weren't cheap bearings either - Chrysler had actually put Timken bearings in when they built it. He opined from the appearance of the race and the rollers, it looked as if someone had cut corners on assembly and hammered that bearing in to save time. Said if I'd waited any longer, it would have started chewing up the gears. Put in the new bearing kit, along with some new axle bearings to boot, and Amsoil 75W140 oil.
HALLELUJAH!!!! Noise was finally gone, and the thing drives like a dream, better than when new.
And no, I don't have a GDE tune on it - just an Inmotion Stage II. Original pre-F37 shift points.