Can a loose timing chain rattle
 

All summer I have been thinking this rattle clunking sound is from my transmission but everything in the tranny is mint. So if now I'm looking into the engine end of things, would the timing chain be first to check when searching for a clunking rattle at low rpm and hot.

Did you check your dampener plate? That is the common rattling sound in these trannys.

It is possible for the timing chain to have so much slop that it hits the cover. Usually if it is excessively loose you will have other problems such as hard starting from little or no cranking vacuum and lack of performance. Should be able to find the source of the sound using a long screwdriver or, better yet, a mechanics stethoscope.

Note: if your wife has a stethoscope from her occupation she will not see the crossover use as reasonable.:rolleyes:

Most definitely your damper plate! I just went through this last year with my 1989.

Here's what you need: http://www.skidim.com/prodinfo.asp?number=R140001