With 2005 mountaineer i have replaced front wheel hubs and both front sensors truck seems to loose power sometimes also turning to right hear agrinding noise

The code refers to the right front wheel speed sensor. The fact it is intermittent says that you have a bad connection or a fractured wire or a bad ground. Check out the videos

C0040 - OBD II Trouble Code: Right Front Wheel Speed ...

https://repairpal.com > obd-ii-code-c0040
C0040 18: Code C0040 18 indicates the ABS module has detected the right front wheel speed sensor signal amplitude is below minimum. More OBD-II Codes. C003E.

Video Help

possible a loose front wheel bearing or a failed front wheel bearing
the abs light sensor is probably touching the rotor
tack it back to the shop that did the job as there is a problem in the assembly of the unit.

if the clicking noise happens when turning the wheels while driving, the most likely problem is the output axle shaft ( drive axle ) when the boots rips you loose grease and they start to grind and clicking and brake away. ( recommended to bring to an auto repair shop ) roughly price on drive axles are $125 for the part and 1.5 hours labor.

Now, if those noises could be duplicated without driving ( just moving the steering wheel side to side ) it could be a bad ball joint or pitman arm.

I really don't think that the brake light is related. I would go straight to your mechanic and avoid all pot holes and drive slowly.
Good luck.

hub bearing or possible front differential

Wheel bearing on the right front

If it gets worse as you're turning right, but not left - Most definitely a wheel bearing on the right side. The right turn puts more stress on the right wheel - louder noise - turn left and release the stress - no noise. You can also lift the vehicle up on a jack and listen to the wheel and hear the bearing in the hub making noise.

This is a condition known as over active ABS. GM has a technical service bulletin for this. Basically what it say is to remove the front wheel speed sensors from the hubs, clean the mating surface between the sensor and the hub, apply some di-electric grease over the cleaned area, and reinstall the sensor.

You can try this on the front sensors and see if the problem goes away. I will warn you that you need to be very careful removing the sensor from the hub as they can break off. If it breaks off in the hub you will need to replace the hub and bearing.

You can also check to see if one of the front wheel bearings is loose. with the tire off the ground grab the tire at the 12 and 6 position and push/pull. if the wheel moves and you can see the rotor moving also than the wheel bearing may be sloppy enough for internal exciter ring to get an excessive gap from the abs sensor.

The easiest thing to do is look at wheel speed data on a higher end scan tool. When the symptom happens you will see the wheel speed drop out. Whatever wheel drops out is the wheel that needs to be checked.

Hope that helps.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

The sound could be isolated and may not be related to you not having 4wheel drive. You may have to inspect the speed sensors on the hubs of the wheels. You may have it inpsected and see if there could be a faulty sensor. Some 4x4 relies on sensors for 4x4 to work and these sensors also help ABS to work. Inspect the drive shafts as well. This may have caused the noise and may have affected your 4wheel drive capabilities.

The 4 Bolts that Hold the HUB in Also Hold the Backing Plate
Hub Replacement - Rear (Front Wheel Drive/Drum)

Removal Procedure

1. Raise and support the vehicle.
2. Remove the tire and wheel.
3. Remove the brake drum.
   1. Remove and DISCARD the wheel bearing/hub bolts.
   2. Remove the wheel bearing/hub.
   3. Disconnect the wheel speed sensor electrical connector (2).Installation Procedure
   4. Connect the wheel speed sensor electrical connector (2).
      1. Install the wheel bearing/hub. Caution: These fasteners MUST be replaced with new fasteners anytime they become loose or are removed. Failure to replace these fasteners after they become loose or are removed may cause loss of vehicle control and personal injury. Notice: Refer to Fastener Notice in Service Precautions.
      2. Install the NEW wheel bearing/hub bolts.
      • Tighten the NEW wheel bearing/hub bolts to 80 Nm (59 lb ft) .
      1. Install the brake drum.
      2. Install the tire and wheel.
      3. Lower the vehicle.

This can be from warped rotors. Also try cleaning rear abs sensors. What happens in rear is brake dust does not have momentum at low speeds to fan out away from wheel sensors. Loose debris falls into abs sensors and makes abs activate. Big culprit in rear is emergency brake linings separate and get crushed then foul sensors.