Stange automatic transmission noise.

About 1 week ago I changed transmission oil and filter (removed pan and cleaned and put new filter and installed pan).
I was extremely carefull about making sure everything was perfectly clean and that no dirt got into transmission.

I did a two years before a transmission oil change only.

Everything was fine until today.
Coming home from work, car started to make funny noise.
Noise like something is rubbing against a gear as it turns and slows down as the cars starts to slow down.

This noise only happens when you let off on the gas, and the car starts to slow down and goes away just before you stop.
Braking and no braking makes no difference.
Putting the car in NEUTRAL makes no difference.
Stepping on the gas noise goes away until again you let off on the gas, and the car starts to slow down.
Driving along and turning off the car and putting into NEUTRAL and the letting the car coast produces the same noise.

The noise is not present at idle or shifting through all gears while car is stationary.

Could it be a wheel bearing problem?

Could it be a fluid problem?
I don't think so because car shifts through all gears properly.

Could the new fluid and filter maybe knocked dirt or something loose and now it is in the axle and drive gears?

Could the new fluid and filter maybe have loosen-up some axle + drive gear problem I that I could have had before but did not know about.

I am debating about changing transmission oil and filter again.
I am debating about going and getting a transmission flush.

 

what fluid did you use, how much did you use and did you burp all of the air from the system before driving it?

 

1) ATF, it was red/pink color.....not oil, light brown color.
Mobile 1 Synthetic ATF
http://www.mobil.com/Canada-English/...thetic_ATF.asp
Used it before with no problems
Used it in other cars with no problems

2) About the same what I took out then , after starting the car and shifting all gears and then measuring and adding until level is between the two marks at 20C. Drive one day and check while hot to see if level is between the two 65C marks after shifting through all gears ( which is was).

 

It sounds like you did the right procedure on servicing the transmission but I'm not sure about the fluid you used.

That Mobil1 synthetic says it's designed for SUV's, and heavy truck use. It says it is compatible with Mercon but doesn't specify which level of mercon.

 

Mobil 1 Synthetic ATF has the following builder
approvals:

Allison C-4

Ford Mercon

General Motors Dexron III

Applications
• Mobil 1 Synthetic ATF is recommended for use in modern high performance automobiles, SUVs, SUTs,
vans and other light trucks requiring Dexron III and Ford Mercon performance levels.
• Suitable for use in older vehicles which originally required Ford Type H and Type CJ fluids.
• Off-highway, heavy duty transmissions requiring Allison C-4, Caterpillar TO-2 performance
• Not recommended for Chrysler Type 7176 ATF.
1 of

 

I still have my spare transmission laying around

remember that door stop Rod