A common problem while installing a u-joint is to drop a cap and have one of the needle bearings fall out. If you replace enough u-joints that will happen! You didn't happen to drop one and possibly knock a needle bearing out did you? That will cause it to not work correctly...
Mike

 

im not totally sure my caps were pre greased and it was pretty thick grease so i didnt think anything was going to fall out, and it didnt take me long to hammer the new ones in, would the symptoms of a lost needle bearing affect anything when im in 2wd or would it just be 4 wheel.

 

That may be your problem... You should press those in with a vice or press. If you think about it those needle bearings aren't in there that good with the grease that some hard hammer blows couldn't knock 1 or more of them out.
Did all the snap rings seat down in the grooves? Maybe you could take a look on the floor where you were working just to see if you find any bearings...
Mike

 

I too have replaced both front wheel u-joints and am now noticing a binding in 4 wheel that wasn't there before. Any suggestions?