Originally Posted by fgocards
Okay so my Jeep has a whine it gets above 45mph that gets really loud around 60-65 and only makes the noise when you step on the gas pedal.
It sounds exactly like that. Anyway I thought it was the rear diff so I changed the fluid and didn't noise any pitting or wear. There was also no metal shavings in the oil either so I don't THINK that it is the rear diff but I could very well be wrong.
My question is, could it be the front? It sounds loud in the cabin but I didn't think it could be the front because as far as I knew you only use the front differential in 4x4 mode.
If not I'll have the have the back rebuilt, and IDK how much that costs... Anyone know?
Either way this sucks and sorry I'm ranting but I also have the replace the bushing on the front differential because I'm getting that oh-so-famous "CLUNK" when I switch from Park to R to D, etc...
Any help appreciated, thanks!
Your jeep is basically all wheel drive so the front diff is always turning , so yes it could be front or rear .you seem to have it down , but here's what the manual says about diagnosing gear noise , not so much front-rear but gears ,pinion , axle bearing in general . maybe you can narrow it down further yourself a bit .
Axle gear noise can be caused by insufficient lubricant, incorrect backlash, tooth contact, worn/damaged gears or
the carrier housing not having the proper offset and squareness.
Gear noise usually happens at a specific speed range. The noise can also occur during a specific type of driving
condition. These conditions are acceleration, deceleration, coast, or constant load.
When road testing, first warm-up the axle fluid by driving the vehicle at least 5 miles and then accelerate the vehicle
to the speed range where the noise is the greatest. Shift out-of-gear and coast through the peak-noise range. If the
noise stops or changes greatly:
² Check for insufficient lubricant.
² Incorrect ring gear backlash.
² Gear damage.
Differential side gears and pinions can be checked by turning the vehicle. They usually do not cause noise during
straight-ahead driving when the gears are unloaded. The side gears are loaded during vehicle turns. A worn pinion
mate shaft can also cause a snapping or a knocking noise.
The axle shaft, differential and pinion bearings can all produce noise when worn or damaged. Bearing noise can be
either a whining, or a growling sound.
Pinion bearings have a constant-pitch noise. This noise changes only with vehicle speed. Pinion bearing noise will
be higher pitched because it rotates at a faster rate. Drive the vehicle and load the differential. If bearing noise
3 - 56 FRONT AXLE - C200F WK
occurs, the rear pinion bearing is the source of the noise. If the bearing noise is heard during a coast, the front
pinion bearing is the source.
Differential bearings usually produce a low pitch noise. Differential bearing noise is similar to pinion bearing noise.
The pitch of differential bearing noise is also constant and varies only with vehicle speed.
Axle shaft bearings produce noise and vibration when worn or damaged. The noise generally changes when the
bearings are loaded. Road test the vehicle. Turn the vehicle sharply to the left and to the right. This will load the
bearings and change the noise level. Where axle bearing damage is slight, the noise is usually not noticeable at
speeds above 30 mph.