6 Speed Transmission Hack Now an official GM procedure

Capt Bob · June 28, 2022

Since you didn't watch the vid, it deals with removing exhaust pipe support points rather than connection points. That gives a little more flex in the pipe itself without loosening any pipe connections. I also installed a drain and have replaced 24 quarts of fluid over the last 10K miles. Call it a poor man's flush.

steelerdude15 · June 28, 2022

I have an update for my truck regarding the pill flip. I flipped the pill last May at 30,041 miles. I also changed six quarts of fluid and the filter. Fast forward to now, I have over 41,000 miles and the hottest the transmission fluid has gotten is 165. That’s in stop and go traffic on a hot and humid day with the ac on. Most of the time, it only gets into the 130s or 140s. The fluid is still red and in good shape. It was definitely worth doing it.

Spurshot · June 29, 2022

To get back to those had asked me questions and just fill in blanks...

I used one Harbor Freight ratchet strap ~$8 and just looped it around the pipe behind the Y and the crossmember. I cranked it down to almost touching the crossmember, and didn't loosen or remove any supports or the manifold connections, nor did I loosen the transmission mount and raise the transmission. I was pleasantly surprised when the pan just twisted a bit and came out.

As for fluid in the pan upon removal, I had unhooked the upper line on the thermal valve block, shoved a piece of 3/8" O.D. hard poly line into the thermal valve block (round/taper the edges of the hard poly line to allow it to push in without damaging the seal in the block), and slipped a 1/2" I.D. clear hose over the line that I removed from the thermal valve block, and ran those two lines into a 2 gallon graduated pail (so I could measure fluid removed) I bought at HomeD or Lowes. Here's the step that was a mess...I started the engine and let it idle until all the fluid pumped out. Best to have two people for this. The line jumped out of the pail and sprayed around a cup of fluid all over. Fortunately, I had layed out about a 10 x 10 ft sheet of heavy plastic. Once the fluid was pumped out, the pan only had a little fluid left in it when I was manuevering it out.

I installed the new filter and pan with the drain plug (~$6 ea for GM engine 12mm x 1.75 drain plugs with a seal built-in. I bought 3 from my local Chevy dealer to have a couple spares). Then I filled with the amount of fluid I had collected from draining. I started the engine with the same hose arrangement on the upper line of the thermal valve block as the earlier step, and purged out the remaining amount of fluid that was dark and saw clean fluid (~3-4 qts), equal the total system volume of about 13 qts. During this process, I had to overfill it as I was doing this all by myself. If you have a helper, you can have them add fluid as you purge. I'm confident I have all new fluid in there now, with little to no old fluid in the converter, lines and cooling system.

Edited June 29, 2022 by Spurshot

pokismoki · June 29, 2022

you guys are working too hard, just undo the rear trans mount bolt and lift the trans up off the pad, this gives you the clearance to pull the pan

Spurshot · June 29, 2022

On 6/21/2022 at 9:05 AM, Spendit said:

Spurshot - Curious if the pan drop was as bad as some report - wedging up engine, small hands to twist it out between cross member and all the wood chunks and straps to have on hand? I have the 5.3 CC with 100K now

Not nearly as bad as I imagined. I ran my truck up on 5" race ramps placed between the front and rear tires and backed up the ramps, chocked it, set the brake. You could use a jack and some blocks or jackstands instead. My driveway is slanted and I don't like to use jacks or stands when working under a vehicle, so I use ramps or blocks when possible. This allowed more room to work under it, got the ramps out in front of the front tires and allowed side access, as well leveled my truck in my slanted driveway. Placing a large sheet of heavy plastic down saved a lot of cleanup of the driveway. It was worth whatever that plastic sheet cost. I used a ratchet strap as mentioned above and didn't loosen or jack anything. But I think the thing that helped me was pulling the line and purging all the fluid out before dropping the pan. The pan only had about a quart or less in it when I did drop it. So it was easy to maneuver around and get it out. I was prepared to loosen the trans mount and jack it, but it just wasn't necessary. The cheap chinese ratchet strap sorta folded the sideplates when I tightened it, so I simply cut it loose after the pan went back on.

Oh...get one of those cement mixing tubs to catch the oil spillage.

Medium Mixing Tub A-41 (homedepot.com)

And one of these graduated buckets to measure what you drain...or any other way to measure what you drain and see the color of what's coming out. United Solutions 10-Quart Plastic Paint Bucket in the Buckets department at Lowes.com

The hoses you'll need are a couple feet of clear vinyl 1/2" I.D. and 3/8 O.D. (1/4" I.D.) poly (milky white) hard plastic hose (think ice maker line).

Edited June 29, 2022 by Spurshot

steelerdude15 · June 29, 2022

2 hours ago, pokismoki said:

you guys are working too hard, just undo the rear trans mount bolt and lift the trans up off the pad, this gives you the clearance to pull the pan

How high did you lift the transmission?

Spurshot · June 29, 2022

2 hours ago, steelerdude15 said:

How high did you lift the transmission?

One video I saw mentioned not wanting to lift it more than an inch, due to some wires he was worried about(?) He also strapped the exhaust to the crossmember before jacking the trans.

Edited June 29, 2022 by Spurshot

pokismoki · June 30, 2022

only high enough to slide the pan out after you drained and took all but the last two bolts out, which are left in to dangle the pan for drainage. you can actually lift the trans off the pad as high as needed and reach in and pop out the filter, install new one , no need to take the pan off completely if i remember correctly. i did it this way about 2 years ago.

buy about 4 cans of engine starter (ether), and hose down the transmission with this stuff, it works amaizingly well for degreasing while not damaging plastics or alloys.

Edited June 30, 2022 by pokismoki

Spurshot · June 30, 2022

In my case, at 94,--- miles, I wanted to change the pan itself as well as inspect what was in the bottom of the pan to determine if my converter was shedding debris and killing my trans. So, leaving it hanging wasn't in the plan.

It simply took one ratchet strap pulling down the exhaust to the crossmember, without unhooking anything on the exhaust. I thought it was about the simplist way to deal with the exhaust. No muss, no fuss.

Edited June 30, 2022 by Spurshot
add picture

steelerdude15 · June 30, 2022

13 hours ago, pokismoki said:

only high enough to slide the pan out after you drained and took all but the last two bolts out, which are left in to dangle the pan for drainage. you can actually lift the trans off the pad as high as needed and reach in and pop out the filter, install new one , no need to take the pan off completely if i remember correctly. i did it this way about 2 years ago.

buy about 4 cans of engine starter (ether), and hose down the transmission with this stuff, it works amaizingly well for degreasing while not damaging plastics or alloys.

Yeah, the last time I changed the fluid, I didn't take the pan off completely. Even with the pan in the way, its easy to get the filter out and clean everything.

2017 silverado · February 5, 2023

I just purchased the updated valve. I am also wandering if i should rebuild the new one i ordered using the sure cool kit from superior stl010.

Grumpy Bear · February 5, 2023

On 2/4/2023 at 7:44 PM, 2017 silverado said:

I just purchased the updated valve. I am also wandering if i should rebuild the new one i ordered using the sure cool kit from superior stl010.

You could have done that with the original to the exact same end. The difference is the 'pill'. I've done both. Use the new valve and skip the Superior kit.

Edited February 17, 2023 by Grumpy Bear

2017 silverado · February 8, 2023

On 2/4/2023 at 10:25 PM, Grumpy Bear said:

You could have done that with the original to the exact same end. The difference it the 'pill'. I've done both. Use the new valve and skip the Superior kit.

I would considering how many parts gm has replaced with updated part numbers. People are talking about how good the sure cool parts work and so far so good for me. I ordered the new valve the sure cool kit and the valve gasket all for around $140. I took the new unit apart and all it had inside was the plunger no spring no bearing. If you have a little extra cash then buy the new valve and change the internals if not just install new valve without changing internals.

Grumpy Bear · February 8, 2023

3 hours ago, 2017 silverado said:

I took the new unit apart and all it had inside was the plunger no spring no bearing.

It is that 'plunger' you tossed that IS the difference. It extends at a lower temperature closing the internal bypass.

The kit you installed doesn't have an open temperature. It's always open. The exact same thing that can be done flipping that "plunger' upside down for free. The ST010 claimed advantage is it is spring loaded so that in the one in a million chance the cooler plugs it forces the internal bypass open. You could have also pulled the entire guts, tapped the passage for a Welsh plug and simulated the way they have been plumbed for about 80 years. Factory didn't see a need for eight decades to use a pressure relief valve. The pill flip would have saved you $140 bucks. That gasket is multi use. Just say'n.

16LT4 · February 10, 2023

I've ran my truck with the pill flipped, and now with the 70* updated thermostat. The only reason the pill is still not flipped is to increase the ATF heating rate during NY winters; with the pill flipped during January, I could drive 15 miles and not get ATF out of the 80*F range. On my '16, unfortunately, the ATF heat exchanger is liquid-air, not the liquid-liquid of the last several decades; I wish it was the latter, so it doubled as a heater.

Edited February 12, 2023 by 16LT4