automatic transmission overfill

[Steve M]

I took my truck in last week to have a rim replaced under warranty. While I was there I told the mechanic about the oil level in the rear end being a little low. He apologized and re assured me that 1" below the fill hole is not a problem and topping it off with Valvoline full synthetic GL5-MT1 75w-90 is also not a problem. I think he might have redone his PDI... When I got the truck back, it felt like a brake was dragging. Even at 65mph I was into the throttle to maintain speed. Mileage was down 2mpg. This morning I decided to check each wheel for a dragging brake even though they all felt about the same temp after driving around town. While nosing around under there, I noticed a few spots of oil on the hitch receiver. To shorten the story, my transmission was 1. 5 quarts overfull and the fluid was full of air. I syphoned the level down to normal. Just another thing to check for low power and mpg... Symtoms are dragging, mushy or erratic shifts, harsh engagement when put in gear, and signs of fluid blown out the vent. Vibration is also a sign of air in the fluid.

The mechanic is a very nice person and owns a HO/6spd 4X4. I contribute this to a forgivable oops.

 

[DBVZ]

How far did you drive before you found the aerated fluid? It may be less forgivable if you start having problems. Perhaps the overfull condition was because the aeration caused it to expand. If some problem is injecting air, it would look overfull due to expansion caused by the air. You may want to bring it back, replace the fluid, and have them document what happened.

 

[Steve M]

I didn't notice the dragging until I picked it up from the dealership last week. I drove it probably 250-300 miles. I don't know for sure if they topped it off or if the warmer weather might have allowed the temp to come up just enough to raise the level enough to aerate the fluid. It drives fine now and the fluid is still cherry red and doesn't smell burned. I'll stop by the dealership and let them know what I found. They've been an excellent dealership for almost ten years I've been dealing with them. Hopefully that relationship won't end here...