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-   -   Interesting Notes about the 4T45E Transmission (https://www.saturnforum.com/forum/general-tech-help-13/interesting-notes-about-4t45e-transmission-10615/)

derf 05-15-2016 12:13 AM

Interesting Notes about the 4T45E Transmission
 
2 Attachment(s)
From

GM's 4T45E Transmissions: The Good, Bad And The Ugly

Since it is a blog and will not be around forever, I have copied it below.

DISCLAIMER: I have no clue if any of this is valid, correct, or useful. Use at your own risk. States 25K fluid change interval; contradicts owner's manual.

You make the call.

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GM’s 4T45E Transmissions: The Good, Bad And The Ugly

Posted by Regis on Tuesday, February 12th, 2013

The 4T45E is an automatic transmission made by General motors. The “4” stands for four speeds, the “T” stands for Trans-axle, the “45” means that it can be used in a vehicle weighting up to 4500 lbs and the “E” stands for electronic. Because this transmission was used extensively throughout the entire GM line up of brands, it is wise that as a shop owner, or car junkie, that you are made aware of some of the short comings and oddities of this transmission.

Because many different gear ratios were used to determine the final gear ratio in the trans-axle, much care should be taken when replacing the transmission. A total of four different gear ratios were available and installing the wrong one will play havoc with the computer and all the sensors on the vehicle.

The 4T45E does not use a dipstick to allow the measurement of the transmission fluid level. Instead it has a fill plug on the side of transmission (like a manual transmission). The fluid level should be up to the bottom of the fill level plug. If you only remove the pan it takes 7.4 quarts to refill the transmission up. If a new torque converter has been installed add another 2.6 quarts of oil. If the transmission has been completely rebuild or re-manufactured it will take a total of 10.6 quarts of oil to fill to the proper level.
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Fill and level check locations on the 4T45E transmission

SEE THUMBNAIL 1
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Like every other automatic transmission, overheating is a major cause for concern. It is recommended that an aftermarket cooler be installed in conjunction with the factory transmission cooler.

- Lack of maintenance is a potential problem that you might not be aware of when buying a used car with the 4T45E transmission. It is recommended that the fluid be changed every 25,000 miles. Ask for service records when buying a used car to verify that scheduled maintenance was done in accordance with the factory manual. It’s no trip to Cars Land at Disney, if you purchase a vehicle where the transmission hasn’t been maintained properly. Steer clear of vehicles with no paperwork outlining past maintenance.

- Failure of the 2-3 shift solenoid is a common problem. The 2-3 solenoid is located inside the transmission and requires about 8 hours of labor to repair.

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4t45e_Electrical_componets

SEE THUMBNAIL 2
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- Failure of the TCC PWM, which stands for Torque Converter Clutch Pulse Width Modulation solenoid. The TCC is located inside of the valve body and is part of the internal wire harness. It is highly recommended that the internal wire harness be replaced at the same time you replace the TCC.

- Failure of the forward clutch is another common problem. The symptoms are no forward gears but the transmission still has reverse. Replacement of the forward clutch requires the removal of the transmission and complete disassemble of the transmission.

- Failure of the input sprag clutch. The symptoms are the same as the failure of the forward clutch and are no forward gears but the transmission still has reverse. Replacement of the forward clutch requires the removal of the transmission and complete disassemble of the transmission.

GM realizes that they have to up their game in the transmission department. That is why they are partnering with long time competitor Ford, to work on new transmission technology.

The 4T45E is a fairly decent transmission when not subject to too much abuse. Like any other parts on your car, the transmission has a finite life span. When the time comes to replace the transmission I highly recommend going with a re-manufactured unit. They differ from a simple rebuild in that they bring all spec up to what they were when the transmission was new. A rebuilt transmission will only have the worn items replaced.

Rubehayseed 05-15-2016 06:13 AM

Any ideas of what year models that transmission is in, derf? My son has spotted a 2000 S2 sedan he likes the looks of and the price of. Of course, by the time he gets enough saved to buy it, it'll probably be gone!

02 LW300 05-15-2016 12:15 PM

The L series have the 4t45e with the v-6. My car will slip in first gear at times and will trip the common wrench light when hot. The car commutes just fine, mileage is about 165000.

02 LW300 05-15-2016 12:17 PM

The level check port is not where it is shown in the first diagram.

derf 05-15-2016 10:14 PM


Originally Posted by Rubehayseed (Post 54595)
Any ideas of what year models that transmission is in, derf? My son has spotted a 2000 S2 sedan he likes the looks of and the price of. Of course, by the time he gets enough saved to buy it, it'll probably be gone!

See https://en.wikipedia.org/wiki/GM_4T40_transmission (it talks about the 4T45 as well). Prob not an all inclusive list.....:

By final drive ratio:

Applications:

3.63:1
2005-2010 Chevrolet Cobalt
2005-2010 Pontiac Pursuit
Pontiac Grand Am
2005-2007 Saturn Ion
Saturn Vue Green Line
Chevrolet Malibu 2.2

3.05:1
Oldsmobile Alero 3.4
Chevrolet Malibu 3.5
Pontiac G6 V6
Pontiac Grand Am SE & SE1 w/ LA1 3400

3.29:1
Chevrolet Malibu Maxx 3.5
Pontiac G6 GT
Pontiac Grand Am GT & GT1

3.91:1
Pontiac G6 base
Chevrolet HHR
Saturn Vue XE

Rubehayseed 05-16-2016 07:49 AM

So as long as we stay with the S series, it looks like we'll be dealing with the crappy TAAT transmission, huh? Why the hell couldn't they put a decent automatic transmission in the Saturns?

derf 05-16-2016 07:52 AM

Different Kind of Company

Different Kind of Car

19bonestock88 05-19-2016 10:08 PM

That's interesting... My 4T45 has had no maintenance done, has 148k on it, and works great... There is a slight vibration when accelerating gently at around 20mph, but I've thus far ignored it... When do I ever accelerate gently, anyway?

scoffman 05-25-2016 01:34 PM

If you look at the first diagram the level check port is just above the output shaft tail area. From the red arrow is pointing look up to the top of that section of the transmission and you will see a plug in the picture. That is the level check port.

As a side note the 4T45 has had 4 different valve body designs. You can find this information on the WEB.
'97-'01 GM036 casting number 24209130
'02-'03 GM061 casting number 24214698
'04-'05 GM062 casting number 24216020
'06-'08 GM063 casting number 24233226

I like the information you gathered from that website however I think it is a little biased as the website ETE Reman specializes in re-manufactured transmissions. I have to say a decent transmission rebuild shop will re-build a transmission that will be just as reliable, as a purchased re-manufactured transmission.

One of the things I don't like is how they list the "most common problems" but don't bother to give the breakdown of the transmission build years that experience the problems. For example the TCC PWM solenoid failure is in large part due to the TCC Feed Limit Valve wearing out and thus causing the solenoid to work more frequently, eventually causing it to fail.

As to the other solenoid failures all of them can be tested via the wire harness to identify if the issue is local to the ECM or solenoid itself. If it is the solenoid then depending on how long the issue was happening you might be able to get away with just replacing it.

One paragraph I completely disagree with is:
"- Lack of maintenance is a potential problem that you might not be aware of when buying a used car with the 4T45E transmission. It is recommended that the fluid be changed every 25,000 miles. Ask for service records when buying a used car to verify that scheduled maintenance was done in accordance with the factory manual. It’s no trip to Cars Land at Disney, if you purchase a vehicle where the transmission hasn’t been maintained properly. Steer clear of vehicles with no paperwork outlining past maintenance."

This is one companies fear tactic to hopefully get you to make the decision to buy their re-manufactured transmission and change the fluid according to their recommended intervals, when your new to you used car with no maintenance records' transmission all of a sudden kicks the bucket.

The 4T45e service manual says 100,000 mile fluid change intervals.

derf 05-26-2016 01:10 AM

Thank you for the additional information and for the critique.

Indeed, an article produced from such a source is more than likely to be biased in their favor. The 25K interval is funny.


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