Play in driveline?

[Fern]

When I drive the car there is
play somewhere in the driveline.
It's a 4 speed and it was rebuilt? The rear end was never rebuilt. How do I tell if it's the transmission or rear end?
Thanks

[Filthy Filbert]

Can you better describe this 'play'?

Excessive backlash and you can rotate the driveshaft a bunch when it's in gear and on the ground?  Does the driveshaft move up and down or left and right? Are you getting vibrations? Clunks and pops/bangs when starting out or shifting? Etc. 

[Fern]

Can you better describe this 'play'?

Excessive backlash and you can rotate the driveshaft a bunch when it's in gear and on the ground?  Does the driveshaft move up and down or left and right? Are you getting vibrations? Clunks and pops/bangs when starting out or shifting? Etc.

Theres no vibration. I guess backlash best describers it. It gets worse in the higher gears.

[Chryco Psycho]

Possibly the differential .
the ring & pinion can be fine but the spider gears can get loose causing play , sure grips can be a problem , most have the Auburn cone type as as the cones wear out the spider gears become loose . Replacing he sure grip would fix that , the Auburn type cannot be properly rebuilt & once worn are junk .

[MoparLeo]

Back lash in higher gears ??  Can you be more specific in describing your issue ?  No vibration ? Noises ? If so, what kind and at any particular speed ? Can you make a video with your phone and post it ?

[Fern]

Theres play in all gears. Dont feel it when accelerating, but do when I let off the gas. Seems worse in higher gears when going slower (less rpm).

[Fern]

So, I jacked the rear wheels off the ground and put it in 4th gear, car off. When i move the wheels back and forth (they move only about 1" to 1-1/2") I do hear a clunk as it stops (either rotating back or forth). By the way the driveshaft moves also, but the noise is definatly coming from the rear. The 489 sure grip works and both tires spin when driving, so no slippage. Assuming this is a cone type, can anything be done to fix it?
Or is it better to just replace?
If replacing, what is a good option?
Thanks

[Filthy Filbert]

The cone type shouldn't introduce 'slop' when it wears.   It may allow slop from side to side (when rotating the wheel) but should have no effect on driveshaft slop.

Try jacking up just 1 wheel, leave it in gear and see how much play you have

[dodj]

Probably diff, but if it was me, I'd leave both wheels on the ground and with trans in neutral, see how much the d-shaft can rotate. I don't know how much 'play' is acceptable though.