Transmission Fluid Flush?

[AndyC]

I’m getting ready to change the transmission fluid on my ’99 Silverado and I was simply looking to change the fluid and filter… While I was getting my oil changed the shop offered a transmission fluid flush…

Here’s my question… The Transmission Flush service claims to remove 95% of the old transmission fluid… However, it doesn’t include changing the transmission filter…

I’m wondering which service is recommended… Change the fluid and filter, or This transmission flush service that leaves the old filter in place??? They don’t remove the pan either…
Any opinions?

[tbacon1]

I recently had my '99 flushed and they supposedly changed the filter as well. From what I hear, that is the way to go especially if it's never been done and you have a 1999 model.

[chuck16]

As a rule, I change my tranny fluid and filter every 30-40000 Kms; and every other change I opt for the complete flush.

As my Dad use to say "you can pay me now or you can pay me later" It doesn't cost all that much and you may as well do it when your getting the fluid changed regardless.

Hmm that reminds me I have to get mine in for service soon...

[dclonch1]

DO NOT - i repeat - DO NOT let a shop "flush" your transmission fluid. My family owns at least 3 silverados/sierras and I can tell you from experience that this is a bad move. What it does is jars every little bit of crud loose from your tranny and lets it recirculate into the system. My dad said that a tranny shop told him that they see a lot of these transmissions coming in for rebuilds because the owner had the tranny flushed and it jarred buildup loose and glogged channels in the tranny. Just service your tranny like you should and don't worry about the flushing service. It can do more harm than good.

[AndyC]

Originally Posted by dclonch1

DO NOT - i repeat - DO NOT let a shop "flush" your transmission fluid. My family owns at least 3 silverados/sierras and I can tell you from experience that this is a bad move. What it does is jars every little bit of crud loose from your tranny and lets it recirculate into the system. My dad said that a tranny shop told him that they see a lot of these transmissions coming in for rebuilds because the owner had the tranny flushed and it jarred buildup loose and glogged channels in the tranny. Just service your tranny like you should and don't worry about the flushing service. It can do more harm than good.

That's what I have always understood... I just thought it was odd that the shop didn't intend drop the pan and change the filter.... It seems the best plan is normal fluid and filter change...

Thanks!

Andy

[Phishin]

Mr. dclonch1,
I totally disagree with you. I own a 1999 Silverado 5.3L extended cab with 227,000 miles. I bought the truck new.

Depending on how hard you use your truck, you can usually get 80-120,000 miles out of a transmission if you never service it. If you've never had it serviced and and you have 100,000 miles on your tranny already, flushing it may knock loose a lot of harmful particles and cause failure.

However, I have my tranny flushed every 25-35,000 miles. I've never had the filter changed.....NEVER. They do a total flush of all the fluid.....100% exchange. If they drop the pan and change the filter, you are only changing 4.5 quarts out of approx. 14 quarts. That means that 75% of the old, worn-out fluid is still in your tranny. Plus, changing your tranny filter does almost no good. If your filter (which is just a wire screen) is full of dirt, you got bigger problems anyways.

Plus, when a shop drops your pan, you're just asking for leaks to start. People never seen to be able to put good gaskets and a good prep-job on the tranny pan.

100% fluid exchange is the way to go. I also have a 1992 Suburban with just short of 300,000 miles with the original transmission.

Steve Hulbert

[dclonch1]

Phishin:

I totally agree with you ;-) If you have your tranny flushed on a regular basis from the time the truck is new - it should be fine and will extend the life of the tranny. However, for someone who has never had this done this before, many shops will recommend it after lets say 150,000, never having had it done before. There is buildup in the tranny that WILL come loose and COULD harm the inner workings.

So to clarify:

If you buy a new truck and choose to have the tranny flushed on a regular basis, go for it. Thats a good thing.

If you have never had it done - DON'T.

Ok?

I shouldn't have spoken in absolutes - my apologies - i was simply responding to this posters particular situation.