Rearend Slop Driveshaft Rotates

[95strokerPSU]

Yesterday I was under the car switching back to a rubber trans mount and doing a normal under car inspection, and noticed that with the front tires raised and the rear tires on the ground, I can rotate the driveshaft about a 1/2" either way. No side to side or up and down movement, just slightly rotates. I read some older posts that suggest it might be improperly set backlash. Anyone have any input on this?

Thanks

 

[R.J.]

The Mustang drive train does have a lot of "normal" slop in it. Yours sounds excessive and you might want to check you backlash.

 

[95strokerPSU]

Maybe it's a about 1/2" total (1/4" total). I don't have any howling or weird sounds coming from the rear.

 

[ProKiller]

i'm by far no expert here, but mines about that much too and have no problems.

 

[HISSIN50]

As noted, there's a degree spec (actual length measurements change with different radii DS's, etc) but almost every car I've been under had some driveline slop too. To check the rear slop, I rotate the DS (or companion flange) and note how long it is till the rear wheels start to turn (with them in the air).