Driveshaft and axle 'free play' question..

[sailor2000]

OK.. so my driveshafts are off for new u joints... and have made the following observations...

The input shaft to the front differential ( the one with the flanges) has some fore and aft free play... feels like alot but is probably 20 to 40 thousnadths... I can just see it move... the rears diffs have none... and input shaft rotational free play (lash?) is about twice that of either rear diff... is that 'bad'??? There is no percecptable up and down play...

The main drive shaft slip joint has some side to side play.. I can 'just' feel it rock on the shaft but cannot see any movement... is that 'bad'???

 

[Jones]

RE: Driveshaft and axle

I know the set-up specs to rebuild the differentials are in one of the Deuce manuals though I can't quote them right now. Remember that the tolerances are going to tighten up some as the gearboxes come up to running temps.
'Rotational play is twice', but twice what? I just changed out a differential in the baby HEMTT because I could rotate the flange about 30 to 35 degrees which is too much by anybody's standards. How much play is determined by the gear train and there's a lot of gears in a double reduction differential so you'll never get it all out.
Unlike a shaft with a single key to locate it; drive shaft slip joints rely on multiple splines for fit and so are fairly snug with the grease making them tighter. Try lubing the slip collar grease fittings and see what that does.