6 Speed Tranny Question

Lyall · July 27, 2011

So i had just bought a new 2011 silverado 5.3l 6speed transmission and hvae noticed the tranny seems to shift very weird. The truck was brand new form the factory so other than there test drive i am the only one has driven it. I heard thi transmission learn how to drive and adjust themselves to your driving habits. I was wondering how long this may take? when i was driving to work today i notices it really aggressively down shifted specially when going around 30 km/h. I have about 500km on it now. is this something i should be concerned with or will it work itself out?

lineman · July 27, 2011

My 2010 that i bought brand new was the same way. It had about 320 miles when I got it. I wanna say that around 1500 miles or so is when it seemd to act normal. After I got the truck went on vacation and drove about 2,000 miles didnt notice when go back. At first I didnt care for the 6 speed at all, Im starting to like it now.

ujtruck · July 27, 2011

smart man, ask questions before its too late

drive another 500KM then drop the transmission pan change filter / fluid refill (please don't hook up to a flush machine, never , ever)

Stevens03 · July 27, 2011

The transmission does have adaptive learning and does take a few miles to "work" itself out. I really disliked the 6-speed transmission at first. After a short time of driving it, i really started liking it.

And congrats on the new truck.

Baja 252 · July 27, 2011

Same experience with mine but, it did get better with time. This Spring I got a BB tune, now it's great.

Lyall · July 27, 2011

ok thanks. good to know that it should sort itself out. i will be keeping an eye on it. I also want to get a BB tune. but figured i would budget it for next summer then the truck and worth in more.

ERIE_ONE · July 27, 2011

smart man, ask questions before its too late

drive another 500KM then drop the transmission pan change filter / fluid refill (please don't hook up to a flush machine, never , ever)

Why? I always heard thats the best way? Does the torque converter have a drain on these trucks? Just curious.

ChevyTech77 · July 27, 2011

Without putting the vehicle on a flush machine, or wasting a couple of gallons of transmission fluid along with having to pull the transmission pan a few times, you will NEVER get all of the fluid exchanged in the transmission.

I don't know about you guys but I have always been a HUGE advocate of only changing half of my engine oil too.

wavery · July 27, 2011

smart man, ask questions before its too late

drive another 500KM then drop the transmission pan change filter / fluid refill (please don't hook up to a flush machine, never , ever)

I agree 100%. We pulled flush machines out of our shop years ago.

You can change about 90% of your fluid (including the torque converter by pumping the old fluid out while you add new fluid (after the traditional fluid and filter change and before starting the engine again).

I left a pretty detailed post here somewhere..... I'll try to find it......

txab · July 27, 2011

Fluid change procedure

BlackZ71Silverado · July 28, 2011

Why not hook up to a flush machine? I am not very smart with transmissions.

ujtruck · July 28, 2011

I copied this from another forum and thought this might be some useful information

"Transmission Flushing - Good or bad?

Never, ever flush a transmission. There is no "safe" way to flush a transmission unless you own the flush machine and control it yourself.

Flushing a transmission has several pitfalls...

The most obvious is that the last vehicle hooked up to that flushing machine probably was on it's last leg and was generating tons of debris. Most owners, when the transmission starts to act up, rush to get a "flush" in the fervent hope that it will cure the problem. So... flush machines, by definition, see the worst of the worst. If the lines aren't cleaned, hooked up improperly, oil is reused or recycled, etc....then you are screwed as your transmission gets the dose of debris from the last transmission . No matter how good the intentions of the shop, one simple mistake and your transmission gets the debris.

Flushing is supposed to negate the need for removing the pan, cleaning the debris and replacing the filter... BS. There is considerable debris coating the inside of the transmission pan with miles as anyone who has done this can attest. That is part of the maintenance, removing the pan, cleaning the screens and replacing the filter and cleaning the pan.

All that debris in the pan is laying around in areas where there is little oil flow by definition... it tends to settle in the areas where the oil is quiet and just lies there not hurting anything.... until the "flush" stirs it up and circulates it thru the transmission. What a concept...

Reverse flush????? What logic makes anyone think that it is a good idea to reverse the oil flow path in a reverse flush and flush sediment and debris into areas that are normally protected by filters, etc...???? Stupid idea. Period. No other way to describe it.

"Transmission flush" machines are money makers for the shops and dealerships because they are quick and easy and they can actually charge more money for it under the guise of it being "better" for the transmission... when it is really a detriment.... suckers are born every day...

Read the factory service manuals and point out the place where a transmission "flush" is recommended.

So what if all the oil cannot be removed. A "flush" doesn't remove it all either.

If you really really want to replace as much oil as possible in the transmission, drain the pan, service it by removing/cleaning/changing the filter and reassemble. Refill the transmission with fresh fluid. Disconnect one of the cooler lines at the radiator, put it into a bucket and start the engine. Let the transmission oil pump purge the old oil into the bucket so that nothing is subjected to abnormal oil flow. Start pouring oil into the transmission to keep it full while the idling engine/transmission oil pump purges the fluid thru the system. Easy and quick and gets ALL the fluid out... and eliminates any risk of hooking up to a "flush machine".

FORGET THE IDEA OF FLUSHING YOUR TRANSMISSIONS. Normal transmission maintenance is a good idea. Drop the bottom pan, change the filter and clean everything up and refill the transmission with fresh fluid. Do the cooler line/bucket purge if you are really fastidious about changing all the fluid... but... DO NOT hook your transmission up to a flush machine.

Really now, would you get a blood transfusion from an unknown source that is reusing needles... about the same thing if you think about it. A flush will do absolutely nothing more than a good drain and refill will accomplish... and potentially a lot of harm. Do not take the risk. Just because some have had good experiences (or the lack of a bad experience) with a flush does NOT mean that they will always go good."

ERIE_ONE · July 28, 2011

Ok, I thought a "flush" machine pushed new oil through and collected the old oil in a reservoir? Thinking the "dirty" fluid never went back into the fresh oil line and was disposed of at this point? Each time I had it done I had the filter (screen on my old Ferd) changed as well. Why pay all that money and not drop the pan? I have never used one myself so I'm just learning here.

On Edit: I read the link posted above and that looks pretty simple too. WAY cheaper!

ChevyTech77 · July 28, 2011

Ok, I thought a "flush" machine pushed new oil through and collected the old oil in a reservoir? Thinking the "dirty" fluid never went back into the fresh oil line and was disposed of at this point? Each time I had it done I had the filter (screen on my old Ferd) changed as well. Why pay all that money and not drop the pan? I have never used one myself so I'm just learning here.

On Edit: I read the link posted above and that looks pretty simple too. WAY cheaper!

It does.

ERIE_ONE · July 28, 2011

It does.

So the dirty trans fluid from a "flush" machine entering my trans lines is not of concern? My understanding was the (fresh vs. old fluid) are two different fluid circuits in the machine to avoid contamination.

A quote from the link posted above "Watch the tube until you see bubbles or hear a bubbling sound and immediately shut the truck off." Could this cause air pockets in the trans anywhere resulting in possible damage?