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Hi, all:

Looking for some expertise on my 07 SS sedan. I have had it since day one and it has gotten me to almost 120k miles with no problems. It's an automatic and paid off.

I want to keep her running as long as possible. I have been using standard oil but will be switching to the high mileage synthetic blend. One thing that the oil shops keep mentioning that I need to do is change out the automatic transmission fluid, which has never been done on the car.

I have been doing research, some people say its necessary to change, others not as much. The owner's manual is ambiguous at best. Some say that once the car breaks the 100k mile barrier and if you have not changed out the auto trans fluid yet, you shouldn't do it.

Any thoughts on this? Appreciate any help.

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I like to pay attention to the owner's manual. if you think you have extreme service, pay attention. if not, looks like no need.

that being said, I am about to drop the pan and change the filter on my son's 08. but it has a big dent in the pan, so i have a new pan on the way, and wonder if the dent racked the filter housing. there is also a TSB on at least the 08 for a magnet which is too weak to hold all the filings. the TSB says add a couple magnets (in specific places) when you do have the pan off.

will use an oem filter and full synthetic DEXRON VI.

old wive's tale on the if you did not change it, don't, if you think your tranny is held togetther with old gunk, you need a new one anyway.

and don't let the oil shop charge you for a flush and go without changing the filter or dropping the pan.

this is the TSB I talked about.

Bulletin No.: 08-07-30-040C

Date: July 25, 2012

Subject: Information on Normal Maintenance or Warranty Service for 4T40, 4T45, 4T65, 4L60 Automatic Transmission Oil Pan Magnet Upgrade
2002-2011 GM Passenger Cars and Light Duty Trucks
Equipped With the Following Transmissions:

4T40-E or 4T45 HYDRA-MATIC(R) Automatic Transmission (RPOs MN4, MN5, ME7)

4T65 Transmission (RPO M15 and MN7)

4L60 Transmission and Derivatives (RPO M30 is 4L60, M32 is 4L65, M70 is 4L70)
Do not remove the transmission oil pan unless normal maintenance or diagnosis of a customer concern requires it.

This bulletin is being revised to add 2010/2011 model years. Please discard Corporate Bulletin Number 08-07-30-040B (Section 07 - Transmission/Transaxle).

A new transmission oil pan magnet, P/N 29535617, was released for service. The current square transmission oil pan magnet may become saturated with normal ferrous sediment and the Pressure Control Solenoid (PCS) is now collecting ferrous sediment, making it vary from design. For a given current the PCS electromagnet is stronger, causing the line pressure to be less than needed.

When checking PCS line pressure (refer to Line Pressure Check in SI) and it shows that the line pressure is lower than required (refer to Current-Amps/Line Pressure Chart in SI), for a given current at the PCS or the transmission oil pan was removed (for either normal maintenance or warranty service), only then should the transmission oil pan magnet be upgraded.
1. Remove and discard the original square transmission oil pan magnet and install a new one in the current location (See graphics below for the correct application).

2. Install the second new transmission oil pan magnet in the following location as shown in the illustration.

4T40 & 4T45


Only on 4T65E, the second magnet (left) should be attached to the transmission filter.

If the magnet is attached in any other location, it may cause interference (refer to graphic above).


Note photos from the TSB did not copy.

you should be able to google up the tsb number

oh what the heck.

here you go.

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