Checking AutomaticTranny Fluid

[jhm]

As I was reviewing the procedure in the owners manual for checking the fluid, I got to thinking, do GM techs actually follow these instructions? If they did they would have to drive the truck around until the tranny fluid got to normal operating temp, then go thru the gears, then let it idle for 3 or more minutes, then check the fluid. I can't really picture them doing this. Do they check it cold, what the manual says is only a reference check? I am curious

[GM-Tech]

I got to thinking, do GM techs actually follow these instructions?

 

Not likely. Personally, I like to check it fully warmed up. Do I let it idle for 3 minutes? Maybe, but not specifically for that reason. If it's hot and on level ground, I believe I know whether or not it's within acceptable levels.

 

I may check one cold before a road test so I know in advance if fluid level is going to come into question.

[71GMC_3/4T]

I was surprised how much the level changed when the tranny warmed up.

 

I had driven home, and the truck had sat for an hour or so. I started it, went through the gears and checked it. It read just under the add mark! The temp gauge was down near cold for the tranny. I drove it around for 15 minutes and checked it again after the gauge was at the normal temp (~1/4 way up). This time is was right up there on full, like it should be.

[snoman]

I was surprised how much the level changed when the tranny warmed up.

 

I had driven home, and the truck had sat for an hour or so.  I started it, went through the gears and checked it.  It read just under the add mark!  The temp gauge was down near cold for the tranny.  I drove it around for 15 minutes and checked it again after the gauge was at the normal temp (~1/4 way up).  This time is was right up there on full, like it should be.

 

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It will usually move 1/4 to 1/2 inch on deep stick between cold and hot. You should always check it hot and it is better to be a little under full than over full.

[jhm]

I was surprised by how long it took to get the fluid hot. Driving on the highway, it will take a long time. You need to drive around town so it warms up quicker. I drove 10 minutes on the highway and the fluid was not even warm to the touch.

[toneman]

I was surprised by how long it took to get the fluid hot. Driving on the highway, it will take a long time. You need to drive around town so it warms up quicker. I drove 10 minutes on the highway and the fluid was not even warm to the touch.

 

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Drive it in third gear, or do some WOT passing maneuvers...that'll get the tranny fluid plenty warm soon enough.

[snoman]

I was surprised by how long it took to get the fluid hot. Driving on the highway, it will take a long time. You need to drive around town so it warms up quicker. I drove 10 minutes on the highway and the fluid was not even warm to the touch.

 

<{POST_SNAPBACK}>

 

 

Drive it in third gear, or do some WOT passing maneuvers...that'll get the tranny fluid plenty warm soon enough.

 

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Driving around town in traffic will heat it quicker because the torque converter is the major heat producer when it is operating in its stall range and engine cooling system is less efficeint in traffic too which also builds tranny heat quicker too.