FX4 shake shudder when accelerating from stop only in fwd
07-03-2014, 04:12 PM
#1
2004 FX4
Thread Starter
FX4 shake shudder when accelerating from stop only in fwd
I trust most of you more than any local mechanic shops (they couldn't figure it out anyway). This has probably been discussed on here many times but I can't seem to find it under the keywords.
2004, auto, 4x4, 140k miles. New 295/65/18 tires and rear rotors.
From a stop, accelerate normal and there is a shudder that fades out as speed increases (imagine the truck on some ridiculously knobby tractor tires). No odd noises. Drives normal above 20 mph.
No issue in reverse.
Found transfer case way over full so drained and filled properly (still don't know where the extra fluid came from since trans fluid level is perfect).
Inspected rear diff gears and replaced fluid. Shaft U-joints have no play.
GoPro cam under truck shows engine/transmission/transfer case shake when issue occurs.
Does it the same way when slowing to a stop.
Same issue in 2nd gear. I tried it in 4wd and 2wd, no difference. No shake in 4wd low though. Don't know if this is relevant because the difference in torque and ratio to the wheels may play a neutralizing role.
The shudder pulse matches wheel speed, not engine speed. This is why I feel it's somewhere transmission to wheels.
Thanks for any suggestions guys!
2004, auto, 4x4, 140k miles. New 295/65/18 tires and rear rotors.
From a stop, accelerate normal and there is a shudder that fades out as speed increases (imagine the truck on some ridiculously knobby tractor tires). No odd noises. Drives normal above 20 mph.
No issue in reverse.
Found transfer case way over full so drained and filled properly (still don't know where the extra fluid came from since trans fluid level is perfect).
Inspected rear diff gears and replaced fluid. Shaft U-joints have no play.
GoPro cam under truck shows engine/transmission/transfer case shake when issue occurs.
Does it the same way when slowing to a stop.
Same issue in 2nd gear. I tried it in 4wd and 2wd, no difference. No shake in 4wd low though. Don't know if this is relevant because the difference in torque and ratio to the wheels may play a neutralizing role.
The shudder pulse matches wheel speed, not engine speed. This is why I feel it's somewhere transmission to wheels.
Thanks for any suggestions guys!
