The humming occurs at 50mph and above and on the highway, the jeep is rolling straight. There is no driving wheel vibration here.
The humming + driving wheel vibration occurs at 50mph and above only when cornering uphill to the left.
Tire/rim combo, will change and see if it makes any difference
1) if its a bad shock will it make pressure on the highway when rolling straight?
a bad shock can give issues at any time, but usually after a bump(s) is hit, as it lets the tire oscillate too long
2)3) a bad rim or a wear tire must make the driving wheel vibrate on highway also, right or wrong? mine only vibrates when left cornering uphill.
a slightly bent rim may not be felt in the steering, especially if the tire has been on that rim long enough to have a wear pattern that matches
4) u-joint might be, ill change that even if the mechanic said it is not deffeted.
based on your info, I'd say u-joint is not the problem (unless it does it in 4wd), but check them anyway
5) incorrect pinion angle, will it make the humming/vibration at the right tire or i must feel the vibration under my seat?
same for pinion angle.....hear & feel in the seat more....(hum mainly)
6) rope? good idea..ill hang the mechanic guy if he doesnt fix this problem
now..now...no hanging needed.....
OK..so hum above 50, and then steering wheel vibe above 50 and when turning left....
When turning left uphill, the drivers front corner of the jeep is unloading, and the passengers side is getting more load, especially in the steering department....what does it do when turning right & uphill ?? same thing, different, nothing ??
a) It could be a bad tire or rim that is only felt when there is less load on the tire, such as when turning left uphill.
- Do any of your tires have a wavy tread (left front specifically)??
- or any tread/sidewall deformity ? specifically on the inside tire tread/sidewall of the left front, and the outside of the right front
- have you checked all your rims/tires on a machine to see if any are bent or have any tread deformities ??
- does it change when you put a different tire/rim combo on that corner ?
b) Are the tie rod ends in good condition ? is there any way they could be moving slightly when the load is taken off them while turning left ?
- normally check ball joints too, but you said you swapped axles, so those should be different
c) Does it do the same thing in 4wd as in 2wd ??
- are you sure it is in 2wd (shifter linkage adjusted correctly ?)
d) Any problems with your steering gearbox ? fluid level ? operate smoothly lock to lock when idling & not moving ?
e) Brake caliper & pad sticking on the left front ? rotor warped ? any signs of brake system problems on that side ?
f) Anything look abnormal under the jeep ?? control arms bushings ?? anything broken/bent/missing ??
Not 100% sure what's causing it, but I've seen the things listed cause similar problems. The hum may be from the right front, but the vibe could be coming from either side.
You said you put in a new axle, and the hum/noise was still there, but @ a different speed...did you put the same tires/rims on the same corner ? did the vibe also occur @ 20 mph when turning with the previous axle ?
If you isolate it to things that were re-used after the axle swap:
shocks
tires/rims
steering components
steering gearbox
driveshaft
braking system
control arms
Things not re-used that could be the culprit, but unlikely due to the axle swap:
axle u-joints
diff fluid level/bearings
.