Pinpoint Test S : Vehicle Pulsates Or Shudders In A Straight Line (STRAIGHTLINE Driveline Wind-Up)
WARNING: This page is about a different variant/trim than selected.
NOTE:
4H or 4L is not intended for driving on hard/dry surfaces; using these modes while driving on these surfaces may produce noises like intermittent clunking, but does not damage driveline components.
- S1 VERIFY THE CONCERN
- Drive the vehicle and shift from 2H mode to 4H mode. There should be minimal wind-up in 4H mode during straightline maneuvers (wind-up in turns is normal with some pedal input; 4H/4L is not intended for driving on hard/dry surfaces).
Is excessive wind-up present?
Yes GO to S2. No RETURN the vehicle to the customer. ADVISE about correct 4WD system operation and normal vehicle behavior. - S2 CHECK FOR MATCHING WHEEL AND TIRE SIZES
- Check the wheel and tire sizes.
Do the 4 wheel and tire sizes match?
Yes GO to S3. No ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly. - S3 CHECK TIRE WEAR
- Check each of the 4 tires for wear.
Are the 4 tires worn evenly?
Yes GO to S4. No ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly rotated tires to operate correctly. - S4 CHECK TIRE INFLATION PRESSURE
- Check the inflation pressure in each tire. Refer to the Safety Certification Label on driver door or door pillar.
Are the tire inflation pressures correct?
Yes GO to S5. No ADJUST the tire pressure as necessary. ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly. - S5 CHECK THE FRONT AND REAR AXLE RATIOS
- Check that front and rear axle ratios match. Refer to Driveline System General Information .
Do the front and rear axle ratios match?
Yes RETURN the vehicle to the customer and ADVISE about correct 4WD system usage and normal vehicle behavior. No CHECK the VC label. INSTALL the correct axle(s). REFER to Rear Drive Axle/Differential - Ford 9.75-Inch Ring Gear or Front Drive Axle Differential .