03' Dodge Grand Caravan 3.8 engine trans. is full would it hurt to put 10ozs of Lube Guard in? Would it over fill it to much?

 

Adding any additives to a Chrysler transmission is generally NOT recommended or necessary.

 

1 qt of Lucas when I do fluid filter has helped my trans.
If the trans is low, put fluid in. If it is full, adding more fluid will cause issues. If you're having issues, drop the pan, change the filter, add new fluid ATF+4, and some Lucas (1qt tops). This has solved any issues that were starting to show up in our trans.