[ShadowLT1]

Hey yall,

Just wanted to reach out to the forums to see if anyone has PROPERLY done this procedure per GM spec. My plan is to jack up the car and ensure the car is level. Once the car is up on the lift, remove the transmission drain bolt, and drain the fluid cold until there is no longer fluid coming out of the transmission. I'll then add the exact same amount of fluid that came OUT of the pan plus an additional quart on top with a pump back into the transmission pan and then seal the unit back up.

GM has instructed that we then start the car, shift through each gear range, and then put it back in park. Once done, it then says to make sure the transmission fluid temperature is between 167-176 degrees then unloosen the drain bolt again until the transmission fluid trickles into a "drip" and not a streamline, indicating the fluid is properly full, and thus tightening up the bolt back up and the procedure is now done.

I don't plan on doing a full flush (with the lines hooked up and putting pressure into the transmission) I just want to go with the drain and fill route and introduce new fluid into the transmission while leaving potential clutch material inside the transmission.

I guess my biggest concern is HOW IN THE WORLD DO WE LET THE CAR IDLE TO 167-176 DEGREES ON A LIFT. The GM instruction says we can brake torque the car, but I can assure you I will not do that with my car, nor do I want anyone attempting such stupidity especially on a lift or jackstands! It can cause premature wear and damage (GM WARNS ABOUT THIS) its just mind boggling that recommendation is in the official instructions

My car (2020 Camaro LT1) already takes a long long while reaching those transmission temperature parameters even going on a 30 min drive. I just don't see how our cars will reach those ATF fluid temperatures just idling on a lift, and like I said, I will not be brake torquing my vehicle. If anyone has done this procedure properly, give me some insight on what you did to complete the job. My car is currently at 30k miles, and I'm planning to do this service before 45k miles coming up soon as this car is my daily and I'm a bit of a nerd when it comes to maintenance and doing everything properly per factory specs.

Thank you in advance.


Here's the attached document from GM in all it's glory.

[cdb95z28]

I have done it doing what GM says in the procedure.

I suspect you won't get much out of the level plug when the ATF temps are cold. If the goal of GM is to set the level when the ATF is HOT, with the result being a slight drip, the fluid will be below the level standoff when cold. ATF expands when hot.

[ShadowLT1]

Originally Posted by cdb95z28

I have done it doing what GM says in the procedure.

I suspect you won't get much out of the level plug when the ATF temps are cold. If the goal of GM is to set the level when the ATF is HOT, with the result being a slight drip, the fluid will be below the level standoff when cold. ATF expands when hot.

I won't be checking the fluid when it's cold my bad I should have clarified... i'm going to drain all of the fluid while it's cold to get a starting point to introduce new fluid into the pan. Example: If 6 quarts came out cold, I'll add 6.5 quarts with new fluid (little extra) put the bolt back on the pan... THEN warm up the car to that specific temp range, then loosen the drain bolt and wait for the trickle drip.

Essentially, i'm overfilling the pan cold.... Because I'll make my adjustment when I reach that temperature range and close the bolt when its trickling (properly at level)

[cdb95z28]

Originally Posted by ShadowLT1

I won't be checking the fluid when it's cold my bad I should have clarified... i'm going to drain all of the fluid while it's cold to get a starting point to introduce new fluid into the pan. Example: If 6 quarts came out cold, I'll add 6.5 quarts with new fluid (little extra) put the bolt back on the pan... THEN warm up the car to that specific temp range, then loosen the drain bolt and wait for the trickle drip.

Essentially, i'm overfilling the pan cold.... Because I'll make my adjustment when I reach that temperature range and close the bolt when its trickling (properly at level)

There is no drain plug on our pans unfortunately. The bolt on the bottom of the pan is for level check and removing the bolt will not drain the pan. This is why I elaborated on your initial statement, but I understand ya now.

I had a local shop weld in a bung for me and that helps alot. But there is a plug on the side of the transmission near the shift cable assembly that can be removed for which a fluid transfer pump can be used to suck out the fluid from the pan. I drained the pan this way before I had the bung installed. IIRC, shorten an 8mm Allen key and grab an 8mm ratchet wrench. That combo works in the tight space to remove the plug.

[cdb95z28]

Pics of the above mentioned (rearmost) plug

[Dynamical]

I’ll be doing this soon too but I’ll be dropping the pan so I can change the filter.
I hear you on having to get the transmission up to temp but I don’t think there’s any other way to really do it other than brake torque. Another retarded design by GM

[ShadowLT1]

Originally Posted by cdb95z28

There is no drain plug on our pans unfortunately. The bolt on the bottom of the pan is for level check and removing the bolt will not drain the pan. This is why I elaborated on your initial statement, but I understand ya now.

I had a local shop weld in a bung for me and that helps alot. But there is a plug on the side of the transmission near the shift cable assembly that can be removed for which a fluid transfer pump can be used to suck out the fluid from the pan. I drained the pan this way before I had the bung installed. IIRC, shorten an 8mm Allen key and grab an 8mm ratchet wrench. That combo works in the tight space to remove the plug.

Just now responding to this. WOW good catch, I completely didn't realize that pan bolt isn't a drain bolt, but the fluid level check bolt because of the stand pipe design. So I guess the only real way to drain the fluid from the pain is to either suck it out as mentioned or just drop the pan and replace the filter with new stud bolts. Welp, looks like I'll be dropping the pan lol.

I still think it's going to be a pain idling the car until the proper temp range, since it takes forever to get there considering these cars have a pretty good trans cooling system especially if you have an SS, which I have the LT1.