Tranny Flush?
 

Son took his 2003 Silverado for oil change, the service checks all fluids and makes recommendations. The PU has 100,000 miles tranny fluid is dark. Tranny flush is recommended

What is actually done, when a tranny is flushed?

Appreciate any info

well it depends on WHO does it....but basiclly a tranny line is undone and a "machine" which is really just a piston in a tube with tranny fluid in it. when the vehicle is started the transmission pumps the old fluid to the bottom side of the piston which pushes the new fluid in to the tranny...........it is a fairly safe procedure BUT again it depends on who does it.....Im gonna guess you are talking about Jiffy Lube...what I just described is how they do it......hope this helps

make sure you clarify between a flush and a trans service. a trans service is what many shops are moving towards now, you just remove the pan and change the filter, then top off the transmission. it only changes 3-4 quarts of fluid, but your trans holds about 14 quarts. an actual flush is what chrisbmo described, and is more effective imo.

Thanks

I personally prefer a filter and fluid change. And if you can afford it after a filter change then a tranny flush to have all new tranny fluid installed since a filter and fluid change does not change all the fluid out.

Thanks again