Rear End

I have a 2000 Sonoma Highrider. Its an automatic. When I shift from drive to reverse there is a loud clunk either comin from the read end or the tranny. I just topped of the fluid in the rear end. Im thinkin its slop in the rear end or the tranny. Any ideas?

Check for fast idle and u joints first.

i took the drive shaft out and checked all the pins in the u joints everthing is fine. its the tranny theres slop in it. any ideas why? the fluid is fine? i hope its not about to go out.

How is the idle speed?

it idles at about five hundred. or maby its a grand.

it idles at about five hundred. or maby its a grand.

There is 500 RPM differance there.
Which one is it?

Git rid of one pf you post.
Two post makes two confusing answers.

I think its just above five hundred.

Ya it idles at a lil above 500.