GM Transmission service

[Tiki]

Going to do a preventative trans service at 42k miles. Called the dealer to setup the service and was surprised to hear that they offer either a full flush and replacement or just drop then land and replace the fluid. I’m assuming that either are fine for the remaining drivetrain warranty, but was curious with which option folks have opted for.

 

[mb1500]

Pan drop would be lucky to get 1/2 of the fluid out of the system, if you want all of the fluid to be changed than you’re going to want the flush.

 

[OR VietVet]

At that low of mileage I would also do the flush but have the filter changed as well.

 

[Jason in DLH]

And filter gasket.

That darn little filter gasket....

I’ve always wondered if service techs take the time to do the little things like clean the pan thoroughly, change the filter and gasket, etc... on their own or if you need to specify for it to be done?

 

[Fifty]

I was told the pan gasket is reusable.
Is there a gasket, or o-ring for the filter too?

dang it... another part I need to source

 

[Doubeleive]

my dealer told me they have to pull the pan and change the filter when doing the service, they only offered 1 type of service (full service), no option to just flush-fill etc

 

[Jason in DLH]

I was told the pan gasket is reusable.
Is there a gasket, or o-ring for the filter too?

dang it... another part I need to source

Yeah. Mine came in a kit with the filter and pan gasket, so you might not need to source it. I’d recommend using the actual gasket puller tool though as it’s in there tight! Not sure on the size however. I used a socket to “gently” pound it back in.

 

[Fifty]

Gasket puller tool?

 

[swathdiver]

Gasket puller tool?

A pick.

 

[gat0r]

my SW told me to only do the fluid flush for the 45k severe duty service

then do the filter & then flush @ 90k-100k

 

[Gmfm]

I’m a firm believer in just a drop and swap. The filter replacement and pan cleaning are the important things being done here. When I did mine the magnet was slugged over in break in material. A lot of fluid comeS out during a filter change. Just the nature of flushing machines can provide negative results. In the future if you want to change more fluid out you can do so with a fluid pump through the dipstick. There’s lots of info and videos out there. Here’s a good read

http://www.powaytransmissions.com/Home/TransmissionFlush

 

[STORMIN08]

doesnt the dipstick enter the pan ????? maybe i am missing what you are saying...

i would drop pan, remove filter and drain...then use pressure port to evacuate more fluid from convertor...


reinstall new parts and top off, possibly then running for 5-10 sec in each gear...drain pan only and top off again. you could repeat one more time, but the should be adequate for most services.

 

[Jason in DLH]

That’s what I used first...a vacuum pump that I I originally use for brake bleeding. Worked great at sucking up lots from the dipstick. Then detach one of the cooling lines and aim towards a bucket and start the engine for a short bit to pump some out that way (being careful not to run the pump dry). I was able to pull the pan without dropping fluid. Well. I dropped a bit just like a baby does by not paying attention, but I could have accomplished a clean swap!

 

[Jason in DLH]

Oh, and I also stuck the vacuum line in the slightly dropped pan to get most of the fluid out before dropping it fully.

 

[Bob2C]

Gasket puller tool?

I left the filter gasket and just replaced the filter.


Sent from my iPhone using Tapatalk

 

[number9]

Years ago I owned a new 1999 OBS 1500 Z71. I had 2 friends with same gen GM trucks get their trans flushed and BOTH went out within a couple months.

I was at the GM dealer one day in the service dept and asked a guy where to find the "transmission man". He was an older guy, looked like a neat and orderly fella. He replied HE was the "transmission man." So I told him what happened to my friends and I wanted his opinion on what was best for my new truck. He looked around and leaned in and told me "Don't touch it. Leave it alone and just drive it".

I followed his advice on that truck - NEVER touched the trans in any way. Sold that truck with 116K miles to my brother, who drove it to 230K miles before selling it. No tranny issues ever.

I have a 2002 2500HD that I bought used with 27K on it. I've never touched the trans at all. Now has 185K on it with no issues.

My wife has a 2003 Yukon we bought used with 35K on it. I've never touched the trans at all. Now has 247K on it with no issues.

We recently bought her a 2019 Tahoe with 42K on it. Guess what? I'll never touch that trans either.

 

[swathdiver]

Years ago I owned a new 1999 OBS 1500 Z71. I had 2 friends with same gen GM trucks get their trans flushed and BOTH went out within a couple months.

I was at the GM dealer one day in the service dept and asked a guy where to find the "transmission man". He was an older guy, looked like a neat and orderly fella. He replied HE was the "transmission man." So I told him what happened to my friends and I wanted his opinion on what was best for my new truck. He looked around and leaned in and told me "Don't touch it. Leave it alone and just drive it".

I followed his advice on that truck - NEVER touched the trans in any way. Sold that truck with 116K miles to my brother, who drove it to 230K miles before selling it. No tranny issues ever.

I have a 2002 2500HD that I bought used with 27K on it. I've never touched the trans at all. Now has 185K on it with no issues.

My wife has a 2003 Yukon we bought used with 35K on it. I've never touched the trans at all. Now has 247K on it with no issues.

We recently bought her a 2019 Tahoe with 42K on it. Guess what? I'll never touch that trans either.

Do keep us posted on that 2019 Tahoe's transmission, right around 100K report back in...

 

[number9]

Do keep us posted on that 2019 Tahoe's transmission, right around 100K report back in...

That will be about 4-5yr from now (depending on yearly miles) but if I can remember it I will do it.