loud front banging noise when in 4 x 4

[bardyman]

I have the 4 x 4 up on jacks at the moment and cannot find the problem.
Heaps of great information on this site but, this time I cannot find any info.
I have a 1999 Ford courier (Ranger)4 x4 manual.
The other day I went for a fish on the beach.
As I was driving along the beach in 4 high 4 x 4 there was a loud banging noise
and as I turned over the ruts in the sand left by other cars the banging noise was louder and more constant and stopped to 1 bang every now and then when I drove in the ruts.The banging noise was constant whether I turned left or right over the ruts.I found the driveshaft centre bearing rubber was worn.I replaced this with a new one but, the problem still persists.
In 2wd there is no banging noise,no problems at all
Your help will be much appreciated
Thank you in advance.
edit:If I am driving on the road in 2wd there is no noise at all but,If I put the 4bi into 4wd and take off and continue driving the banging noise is there every now and then.

 

[Andy D]

Put the front end up on stands and start shaking stuff. My guess is an axle U joint. Generally any play in a front end drive, steering or suspension component should be replaced.

 

[bardyman]

Thank you Andy D for comment.I checked ball joints uni-joints anything that I could move.I had a mate come over we put the 4bi up on stands .What we saw was the lefthand and righthand cv joint boots were ripped and sand and dirt in the outer joint.So we decided to pull the cv joints out,when we got them out there was a fair bit of wear on the outer joints and movement.So we thought this to be the problem and ordered a set of outer cv joints.We assembled the new cv joints and put them back in.(I only ordered the outer cv joint not the complete unit as the inner boots were in good condition.)I took the 4bi for a drive in 4wd low and high range, but I still get the odd bang going in a straight line but when I turn right or left the banging is constant.Could I have made the mistake of not ordering 2 complete cv joints because could the inner joints be the problem?I drove the 4bi in 4wd left front wheel free and right in lock and viceversa going in a circle clockwise and anti-clockwise with no banging as I drove.Got out put both wheels in lock drove in circles and the banging noise was back.I just don't know what to do.Should I order the inner joints?

 

[Nhaz]

U joint would be my guess. one where by hand it moves fine but under trucks weight it is hitching and releasing causing the bang noise.

It may be possible to track it down by ear with it up on stands but would be hard.

 

[Andy D]

Heh heh. Maybe apples and oranges but my next to last Grand Wagoneer's front D 44 had an axle U joint that clinked like somebody shaking a pocketful of change. I used it gently in 4wd and it went til the end. They were a bear to replace. I used a sharp masonry chisel to pry open the spindle housing. But if what Ford used in later years was CV joints, and you have one that clanks you need a new one. Or at least doesnt clank. I had a rear axle CV joint that sounded just like a loose wheel seconds before it departs. I replaced it with a good used one. Drive easy in 4wd until you replace it.