Anyone upgrade the Torque converter?

[Wpolonavyguy]

I'm a owner of 2007 avalanche, I've had a few problems I've trouble shot and fixed myself. I had to install a new rear main seal twice as first time I messed it up and didn't pull oil pan before aligning and bolting on. So it leaked until I did correctly second time.
The computer system makes trouble shooting extremely difficult, I chased ghost problems and fixed/replaced good parts.
Ac Delco spark plugs I purchased were garbage and defective three I'm surprised didn't shoot out porcelain like a bullet how loose they were could gap freely twist 1/4in. After buying new Bosch plugs and tune up maintenance most problems gone.
I have a bump intermittently when truck goes into first gear only. Neutral giving gas slight delay catching first gear if try accelerating quickly. Shifts excellent and runs great except the bump.
My mechanic friend said torque converter most likely causing this.
I'm wanting to buy an upgraded/better than stock torque converter if I'm going to go through that ammount of work removing transmission, drive shafts, and all to get it replaced.

Anyone upgraded already? Noticed much improvement or changes?

 

[MWR]

I have an aftermarket converter and it's probably my favorite modification other than the cam. I would contact Chris at Circle D converters and get a recommendation. I would think a slightly higher stall and a tune could make a worthwhile improvement on an otherwise stock truck.

 

[BainMan]

I have a bump intermittently when truck goes into first gear only. Neutral giving gas slight delay catching first gear if try accelerating quickly. Shifts excellent and runs great except the bump.

Driveshaft clunk is common, the slip yoke has a bit of play. I think all GM trucks have this to some degree (dunno about newer models). Is this different than the bump you are talking about?

 

[Deroy748]

yea, i was told by my mechanic this is common on GM trucks. I had a 2010 and 2015 that did this. Not often but usually just as I slowed and then sped up quickly

 

[Wpolonavyguy]

I believe I've tracked it down, thought it was torque converter problem. But actually thinking it's camshaft position sensor causing intermittent problems. I've been chasing pcv air leak bubbles in oil catch cans. Intermittent Ritch fuel codes.

I've about replaced every sensor & part I could think of now most I saved likely still good parts.
New gas pedal, New throttle body, New maf sensor, new intake pressure sensor, new vapor purge valve on fuel rail.
Bought new fuel injectors but haven't tried to swap out yet.
I put new transmission filter in and all new solenoids thinking was causing it.
All I can guess now is camshaft position sensor causing computer to do stupid adjustments not needed causing the delay bump & Ritch mix and other odd random things like idle dropping low at stops.
Will update after I replace should help computer run things correctly I hope.
I did buy ac Delco spark plugs that were junk most had something melted between the metal & ceramic caused many more problems until I figured out & replaced all with Bosch plugs doing much better.
I still get some oil in catch cans through pcv vaccume system/ replaced driver's side head with modified version helped but I still like catch cans. I like to keep as much oil out intake as possible.
About to add new tires bought air pressure sensors as batteries About dead one quit working and check tires message getting old can't wait to be rid of message on dash.
I like the Avalanche very much just not liking the computer controlled engine.
Makes finding problems much harder. Sensors cause engine to adjust throw off other systems.

 

[Wpolonavyguy]

So still thinking torque converter isn't up to par on it's operation. One last sensor to try then ordering a torque converter.
Waiting to swap out VSS on transmission in hopes its computer delays from an inaccurate sensor.
But believe now probably do need the converter replaced itself. Seems like it's delayed engaging 1st gear intermittently & when stopping it dosnt let loose to neutral fast enough causes my idle drop below normal at stops.
I have new fuel injectors and all top engine seals to do soon aswell, trying to make certain no manifold leak.
There is head gasket leaking some oil needs doing same time just waiting for stretch time can have it not drive able.

 

[5 Star Av]

I (and a lot of others on here) would co-sign on your sentiments regarding the computer management of these engines! The glass half full part of me always wants to think that these systems were designed to last and designed with all these sensors to provide multiple layers of redundancy to help avoid major failures, and to make diagnosis and repair easier and cheaper owners, etc, etc, etc.. But everyday I get a little older and a little wiser....and (seems like) everyday I lean a little more towards 'planned obsolescence' and/or other similar CORP practices when trying to understand some of the issues my Av has had in the last 13 months.
It started off track last Nov by developing (what I'm 96% positive is) TCC Lock-up issues causing the ever popular TCC Shudder. Then went completely off the rails right after Christmas by adding an intermittent random misfire and an intermittent collapsing lifter. At that point the guy that goes by BainMan up there gave me some solid advice. He said "I'm afraid you're problem is going to be diagnosis". He couldn't have been more correct.
You may well have a TC issue? most of the ones I've read about though exhibited symptoms more like the shudder? and more than few ended in the under designed TC suffering catastrophic failure and taking out the 6L80 with it's shrapnel. [Two days ago I watched this:

and learned that not only is the TC under built for the Av, it's also used in a way that virtually assures that it burns up? and mostly seems to happen right around the time(90-140k mi) most owners payment booklets get really thin]
I pulled injectors, attached one at a time to 9V battery(to open them) and sprayed brake cleaner through them; all 8 had four equal atomized plumes coming out. Replaced O-rings and reinstall
Also checked for vacuum leak with hose attached to propane bottle. Unless the leak is only leaking somewhere up in the RPM range mine was good?!?!
Please update on the VSS, and good luck!

 

[BainMan]

Driveshaft clunk is common, the slip yoke has a bit of play. I think all GM trucks have this to some degree (dunno about newer models). Is this different than the bump you are talking about?

I'd like to amend my answer, absolutely check your motor mount for 1st gear clunk. I just changed mine yesterday and the clunk is gone now! I thought it was the slip yoke as it is a common issue, but it was 100% the driver's side engine/motor mount.

To test, open the hood, start the motor, place gear selector in D and rev the motor while holding the brake. If the motor hops up and down, this is your issue.

 

[Wpolonavyguy]

So I opened up the top end of motor, so glad I did. Found a common issue almost all 13mm bolts holding on the cylinder deactivation plate on were finger loose. Only 3 needed a wrench to loosen, looked like had been leaking slowly for some time now.
Cleaned area and tightened bolts to 20ft lbs. Another member said should have been 18ft lbs. Luckily I didn't break one hoping it'll hold better xtra 2lbs.
Put back together new injectors seals, unfortunately Amazon injectors two of 8 stuck open hydrolocking cylinders passenger rear x2.
Got lucky no damage except for killing my starter wanted new one soon anyhow.
Couldn't return injectors for refund so left review & spent 500$ for all8 Injectors from O'Reilly.
Two from them didn't match the 6? Found out they were putting acdelco in the box of standard injectors I bought. Contacted acdelco as think they will be wanting legal action with this.
Anyway got back together running great but still bump if mash gas to take off. Intermittent late disengage torque converter when stopping.
Already switched break sensor, hoping front wheel sensors I have will help if not next vss on top of converter waiting to replace if issue doesn't go away.
Believe sensor & computer telling torque converter wrong timing just gotta figure which one.
Will update after I try wheel sensors got front 2 suspension kits for new tires & alignment soon.

 

[Wpolonavyguy]

So update I used much better test computer my brother inlaw has, along with intermittent fuel pump connectivity, small air leaks detected intermittently aswell.
The codes closest to issue I'm bothered by were:
P1 818_00 transmission Fluid pressure valve Position switch drive without drive ratio.
P0 711_00 transmission fluid temperature TFT sensor performance
Anyone recommend how I should go about correcting?
I hate to have to take it into a transmission shop they charge such high rates. But constantly worry if I keep on driving it around it's going to worsen & bigger problem will rear it's ugly head.

 

[Wpolonavyguy]

So I opened transmission bought a b&m transmission deep pan holds additional fluid cooler towing I'm hoping.
Replaced wiring harnesses has solenoid permanently attached so R&R both, during R&R the pressure switch with built in temperature sensor. It had 1 slightly deshaped seal, the films dirty might try refurbishing it IDK.
I did clean up as many electrical connections as I could, used air compressor, & dust brush inside most.
Still have a few grounding spots I haven't gotten to, the computer I found is sensitive & needs good connections/grounding points.
The bump is gone now & the idle dropping low at stops quit aswell.
Computer finally able to control torque converter properly.
Ground in Pic I still need to get in to clean and wire brush improve ground connectivity.