4X ..THUD... noise

[Avitare]

I have a new frequent sound while plowing in 4whl drive. This happens ONLY in 4X4 and most often when turning the wheel

but ONLY when changing from Forward to Reverse or Reverse to Forward...

doesnt matter if in Low range or High range ..

Just one quick but hard THUD. It can be felt in the seat and quite sure it is on the driver side.

note: weeks ago, replaced front driveshaft u-joints with Super Duty/greasable joints and also changed the front wheel joints

(same),.. and replaced the left upper/lower ball joints. Experienced Ford shop that mudruns (or did) Broncos, did the work.

Last week, considered the rear joints but they checked out smooth. He advised not to replace and considered the stock joints

stronger than replacement ones (?? that so??)

Used to think I had to be plowing and turning the wheel hard to get the pop/thud. Noise used to be rare and I think used to happen

once in a great while -- before the new joints. (usually at full hard turns --changing from F to R or R to F)

Just in the last few days,.. the noise/thud is happening more often to make me nervous.

More snow coming.

full size 95, automatic , floor shift 4x4, auto hubs (that seem to work great -- with a little patience and no abuse)

California truck with no rust and pretty clean.

Proud of my work 'horse' -- (all) black, aka ATF or aka Vader

appreciate your advice

past help with broken mirror mount and noise from slip joint 'slop'-- right on. thanks

tc

 

[Seabronc]

I know it is not a good time for it, but check out the U-joints on the drive shaft. Put it in 4x4 and try turning the drive shaft by hand while looking at the U-joints. There should be no play in them. Since they usually are ignored during lubrication the bearings inside the caps may have worn.

Good luck,

>-

 

[Avitare]

Thanks but the Ujoints were all just replaced and lubed.

This isnt a light sound,.. this is like the sound of a spring moving,..pop/thud

as loud and as hard as a palm of your hand whacking the fender

we are going to put her on the rack and certainly check the ujoints -- again

but it really isnt that kind of a sound

this thud actually makes a vibration in the vehicle and can feel it

tc

 

[gatorbronco]

This probably isn't it since you're not moving when you hear the thud, but have you checked the radius arm bushings? I know they can make some noise when they're worn out, but not sure if they do it while parked...

 

[shift1313]

another thing that may cause a loud noise would be the rear end clutches. If they are extra tight, when turning. just a thought for you. is it possible that one of your wheels is touching the steering stop and the other isnt, and when you start to go the suspension gives enough to let the other "slam" into the bump stop? does it do it with just a small turn?

 

[Justshootme84]

I would also suspest a suspension problem, either the radius arm bushings or the axle pivot busings being worn. Often, when making a slow turn over uneven ground (like turning into your driveway) a worn pivot bushing will "pop" or make a loud thud. JSM84