zm1040

I feel like my truck is not performing quite as well as it should.
I bought the truck at about 132,000 on the 5.3 from a small car lot in Austin, and I'm now at about 140,000 miles, so I really don't know how the truck has been maintained. I know it needed and received an oil change when I bought it and I have used nothing but high-mileage stuff from Valvoline every 3,000. I have been thinking about a tune up and maybe an injector cleaner treatment just to make sure everything is how it should be. Is there anything else I can do to make sure everything running as intended?

Oh and I did run into some 4L60E tranny issues about 700-800 miles ago... Something broke in the torque converter and caused some of the soft parts to become damaged, so it was partially rebuilt and has had fluid replaced, etc, so that should be running well... Which brings me to another issue in which somebody might be able to provide some insight: Before the tranny problems, I had always noticed a fairly firm shift when going from first to second. Now, when shifting from first to second, the tranny actually shifts and then there is usually a noticeable jerk after the RPMs drop. I have taken it back to them (AAMCO of San Marcos, Tx), and they have taken it for test drives and insist everything is running as it should.
There is also a squeak/squeal/whistle? when putting it into park from neutral or reverse after it has been driven for a while... Idk what that is about. They said it could be needle bearings settling after the repairs, or some BS, but I don't think they'd still be "settling."

2wd-K5

a tune-up may be in order, if in doubt, just do the tune then you know what you are working with, for all you know it may have never been done, and dont forget the di-electric grease on spark plug contacts

zm1040

Awesome, thanks for that tip. On that note, I have tried to get the spark plugs out before to check if they were lookin' bad, but neither me or my father could not figure out how to get them out... We aren't stupid, and he has decent knowledge on cars, but there didn't seem to be anywhere for a socket to grab on... Do the LM7 need super this sockets to fit?

2wd-K5

did you try extensions? or a swivel for a 3/8 drive? some will probly be hard to get

Mille Racer 69

I use my motorcycle spark plug remover on the truck to get the plugs out, just took 'em out today to inspect. they came right out.
1-your spark plug remover is too small
or
2-your spark plug remover is too big.

the plugs are normal small plugs, not big at all.
FYI spark plugs come in different sizes, make sure your
plug remover fits into the block and grabs onto the plug

Also, change out all your filters: air, fuel oil etc.
also take some fine grit sandpaper and sand the plugs a little bit when you get them out.

zm1040

I will keep that all in mind thank you very much! I think I am going to stop by Autozone tomorrow to pick up a socket cause we have tried all of ours and they do not fit that tiny hole around the plug.

Hunter18

not to do with the tranny, but may wanna try getting a can of mas airflow sensor cleaner. i cleaned mine when power started going to crap after i bought it and ended up regaining my milage and power...

zm1040

Is there a particular brand of that and/or fuel injector cleaner I should go for?

therewolf

Hi zm1040,

Welcome to the Chevy Forums.

After all was said and done with your transmission issues, did they install a new transmission filter? As they start to clog,(maintenance cycle @ every 40K)
the tranny will begin to fight the forward momentum of the drive train, resulting in a power and MPG loss.

Your vehicle, when you first acquired it, was overdue for 4 maintenance cycles if the tranny filter had never been changed up to that time.

zm1040

Yes I checked my receipt today and they charged me for a tranny filter, so it should have one.