Transmission Flush or Drop Pan?

Joined
Sep 2, 2010
Messages
38
Location
Louisiana
I took my 2018 GMC with 48000 miles to the GM dealer for a trans fluid and filter change. Turns out I was about to get a flush, so I threw a shoe and insisted on a pan drop and filter change. I got it; including a fluid change in the transfer case it cost $600. Am I right in claiming GM recommends a pan drop and filter change, and not flushing?
 
Joined
Jan 7, 2022
Messages
410
Location
Chicago
i had 6 commercial GMC sierra 3500hd dual wheel tow trucks that did around 30k a year and i had the dealer use the machine to exchange the trans fluid yearly...think it cost like a 150 maybe 200 to do it that way. the filters are just a mesh screen so you can put on a magnafine trans filter and avoid the mess of dropping the pan. think you might have gone a little overboard :)
 
Joined
Aug 23, 2020
Messages
673
Location
Canada
Depends on how much towing or hard driving you do, and how the fluid looks when they drop the pan. Dealer just defaults to the flush option that could be more then you need.
 
Joined
Dec 19, 2013
Messages
7,157
Location
Fort Worth, Texas
i had 6 commercial GMC sierra 3500hd dual wheel tow trucks that did around 30k a year and i had the dealer use the machine to exchange the trans fluid yearly...think it cost like a 150 maybe 200 to do it that way. the filters are just a mesh screen so you can put on a magnafine trans filter and avoid the mess of dropping the pan. think you might have gone a little overboard :)

Incorrect.....The filters use a Felt Filter Media. GM hasn't used screen filters since the 70's.

Every 50-80,000 miles is a good rule of thumb for dropping the pan & changing the Sump Filter.
 
Joined
May 4, 2017
Messages
471
Location
VA
A "flush" is not the way to go. What should be done is a fluid exchange. Why? Draining the fluid and dropping the pan results in about 50/50 mix of new and old fluid as this procedure does not drain the torque converter nad other parts of the transmission. An exchange literally "exchanges" all of the old fluid with new fluid. Now, depending on the vehicle is driven a drain, pan drop, new filter and a fill should be done at 50k miles max. The fluid exchange should be done every other transmission service.
 

4WD

$50 site donor 2023
Joined
Sep 21, 2010
Messages
20,670
Location
Texas via IAH
6L80E: First pan drop I changed the filter and installed a B&M drain plug … I dump 6 quarts each Spring - Takes 15 mins and got valvoline dex vi for $6/quart … Filter/pan will go 60k … So much cleaner for those with plug
 
Top