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The GM 5L40-E Automatic Transmission: Common Problems

John is a fervent writer, gamer, and guitar lover. Former automatic-transmission repairer, welder and hobbyist game developer.

GM's 5 speed automatic transmission was used widely between 2000 and 2007.

GM's 5 speed automatic transmission was used widely between 2000 and 2007.

The GM 5L40-E transmission is very common in cars of a certain age and, as those cars continue to age, more and more of them are finding themselves in the shop for transmission faults. Fortunately, because the 5L40-E has been around for some time, a lot of the faults you’re likely to find are well known and understood, and in this article we’re going to look at some of them.

Be warned, however; even armed with the knowledge this article is going to give you, there is no guarantee you’ll be able to fix the problem yourself… unless, of course, you happen to have all the tools and equipment you’d need.

Please be aware that this article assumes some (but not a lot of) working knowledge of cars and terminology.

The GM 5L40-E Automatic Transmission: A Brief Overview

Before we get into the faults and foibles, I thought I'd include a little bit of background information on this transmission. I've also included a nice video overview below.

The GM made 5L40-E (sometimes referred to as “A5S360R”) automatic transmission is a five-speed transmission that saw common use between 2000 and 2007. There are many vehicles that use the 5L40-E, but some of the more common instances include the BMW 5 Series (E39), L322 Range Rovers, and a range of Cadillacs—check the end of this article for a more comprehensive list of vehicles. It features five forward gears and one reverse, with 4th gear being a 1:1 ratio and 5th gear being “overdrive.” The 5L40-E can come in both two- and four-wheel drive flavours, though many of the components used are the same or very similar.

GM 5L40-E Common Faults Covered Below

Slipping/Power Loss When Cold

Juddering and/or Leaking Fluid from Pump

Slipping/Power Loss When Warm

Output Shaft Wear

Harsh Gear Changes

Complete Loss of Drive

Slipping/Power Loss When Cold

Symptoms:

  • "Flaring" into gear
  • Loss of power
  • "Trans Failsafe" mode
  • ONLY when cold

This fault is up at the top because it’s usually the simplest to fix. If your transmission seems to slip first thing in the morning, or when it's been sat unused for a while, it’s probably a bit low on transmission fluid. As the transmission warms up the oil thins out and expands which, in turn, raises the fluid level, but when it’s cold the fluid level is lower. If the level is low enough, the transmission might struggle to get enough fluid to apply the clutches, hence the slipping.

If this is your problem, you can perform a temporary fix by topping up the oil level; however, I must stress the “temporary” part. If your 5L40-E is low on transmission fluid, that fluid must have escaped somewhere, and if you don’t plug that leak, you’ll be topping up your transmission fluid indefinitely... and that's assuming you never run it too low and burn out the box.

Common places for leaks to occur are around the sump (metal pan underneath the gearbox), from the rear seal around the output shaft, or from the pump seal. Unfortunately, a leaking pump seal would require the removal of the transmission to remedy. This does tie in nicely with the next fault, however.


Juddering and/or Leaking Fluid From Pump

Symptoms:

  • Juddering when driving
  • Fluid leak at the front of the transmission

Though it’s possible for a pump seal to wear down on its own, in 5L40-Es they tend to leak because of a more severe problem. Behind the pump seal is a bush that is responsible for keeping the torque converter steady and central as it spins. In this particular transmission, they seem to wear down relatively quickly, allowing the torque converter to “wobble” slightly. In addition to certain driving issues such as a juddering sensation, this “wobble” squashes the seal out to the point that it begins letting transmission fluid through.

The best case scenario here is that you catch the problem early and “only” need to remove the transmission from the vehicle, remove the front end of the transmission, dismantle the pump assembly, and replace the bush and seal. However, in some cases, this issue can cause damage to the torque converter neck and even the pump itself, and replacing those parts is sure to run you up into a four-figure bill!

Slipping/Power Loss When Warm

Symptoms:

  • "Flaring" into gear
  • Loss of power
  • "Trans Failsafe" mode
  • ONLY when warm

It may seem counter-intuitive, but transmission slippage when warm is an entirely different issue to slippage when cold. Where a low oil level is exacerbated by cold temperatures, warm/hot oil is not, so slipping when warm is indicative of another problem (crucially this only applies if the transmission is fine when cold).

As mentioned above, the transmission fluid expands when it heats up. This not only causes the oil level to rise, it also causes it to become thinner. Automatic transmissions employ a lot of pressurised components that maintain their pressure through a variety of seals and valves. When those seals start to wear, transmission fluid can escape, lowering the pressure. In cases where a transmission is worn but not completely gone, it may drive fine when the oil is cold and viscous. When that oil heats up and thins out, it can start finding its way out of these worn seals and valves, causing a lack of pressure when applying a clutch.

Unfortunately, when this happens, there’s not much to be done below a complete rebuild that can cure the problem. Below is a video on replacing the clutch pistons in a 5L40-E. Due to GM's use of "moulded pistons" rather than regular seals, re-sealing is not as simple a task as it would be in other transmissions.


Output Shaft Wear

Symptoms

  • Partial or complete loss of drive
  • Loud metallic noise when attempting to drive

Typically limited to larger four-wheel drive vehicles such as Range Rovers, the output has been known to wear down to the point of no longer functioning. Worse still, the entire drive of the vehicle passes through this shaft, so when it wears down, the vehicle no longer drives at all—and tends to make a horrendous racket when it tries.

The shaft is connected to a drum inside the transmission, and as the drum is at the back of the gearbox, not only do you need to remove the transmission to replace it but you also need to take all of the guts out of the gearbox to get to it! The one silver lining here is that the wear of this shaft is external to the transmission, and will not cause any damage to the rest of the box.

Harsh Gear Changes

Symptoms

  • Harsh gear shifting
  • "Trans Failsafe" mode

When an automatic transmission like the GM 5L40-E changes gear, oil is fed into a sealed chamber, forcing a piston to push against a stack of clutch plates. If the oil were just shot into that chamber all at once, the clutch pack would apply with a harsh thud and make for a very unpleasant driving experience. The 5L40-E gets around this problem with the use of a number of accumulators which allow the oil to be fed in gradually until the pressure is sufficiently high.

The accumulators work by sitting a small sealed piston on top of a spring so that when the oil is fed into the chamber, it pushes the piston against the spring. These springs, however, have a nasty tendency to break. Fortunately, repairing this problem is (relatively) easy. You don’t need to remove the transmission, just the valve body which can be found inside the sump at the bottom of the transmission.

This picture shows the four accumulators removed from their housing. The accumulator spring on the far right has broken in two.

This picture shows the four accumulators removed from their housing. The accumulator spring on the far right has broken in two.

Complete Loss of Drive

Symptoms

  • Partial or complete loss of drive
  • "Flaring" into gear
  • Loss of power
  • "Trans Failsafe" mode

This is the big one. The most common reason for a vehicle running a GM 5L40-E transmission to end up in a transmission repair shop is torque converter failure. For a variety of reasons (torque converter solenoid, worn valves, worn converter) the converter fails and begins contaminating the oil with debris. The debris circulates throughout the transmission and, eventually, begins blocking the filter. Once the filter is clogged up, the clutch packs are starved of oil and begin to slip. The slipping clutches begin to burn up, further contaminating the oil with debris and, well, you get the picture.

If you were very attentive and caught this problem very early, you might get away with an oil flush and a new converter/filter (though I'd be sceptical over how long you'd get away with it for). For most motorists, however, nothing less than a full rebuild and replacement converter will remedy the problem. The easiest way to check for this problem is to remove the sump and check for debris. If the converter has failed in this fashion, the sump will be full of metallic debris.

A failed torque converter will leave metallic debris in the sump of the transmission.

A failed torque converter will leave metallic debris in the sump of the transmission.

Please remember that this article is only detailing the most common problems with the GM 5L40-E transmission, and the most common causes of those problems. There are other faults and there are other causes of these faults—they’re just far less common.

Vehicles Using the GM 5L40-E Automatic Transmission

Though I'd never be so bold as to claim this to be an exhaustive or complete list of vehicles, it is a fairly comprehensive one. Please be aware, however, that there are always exceptions, such as cross-over years where a manufacturer moved from one transmission to another, and even modified cars where a previous owner has fit a different transmission.

The L322 version of the Range Rover is one of the more popular vehicles to utilise the GM 5L40-E automatic transmission.

The L322 version of the Range Rover is one of the more popular vehicles to utilise the GM 5L40-E automatic transmission.

Vehicles Using the GM 5L40-E

2004-2006 Cadillac CTS (RWD)

2005-2006 Cadillac STS (RWD)

2004-2006 Cadillac SRX (RWD)

2006 Pontiac Solstice

2007 Saturn Sky

2004-2006 Holden WL Statesman/Caprice (RWD)

2005–2009 Chevrolet Omega (RWD)

2006–2009 Holden VE Commodore (RWD)

2008–2009 Pontiac G8 (RWD)

2004–2006 Cadillac CTS (AWD)

2004–2006 Cadillac STS (AWD)

2004–2006 Cadillac SRX (AWD)

2002–2005 Range Rover (L322)

BMW 3 Series (E46)

BMW 5 Series (E39)

BMW Z3

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

© 2016 John Bullock

Comments

Augie on June 14, 2020:

5l40-e transmission can't get shift valves back in

Asgeir on March 01, 2020:

My transmission wont shift too 4 gear just going too failsafe?

Ron ooke on December 18, 2019:

Have an older Rolls fitted with the GM box I have fluid pushing out of the dip stick please advise where the breather is situated so I can check if is blocked

Chris on October 30, 2019:

Hi John,

We have a 2004 bmw e46 with the 5 speed gm auto box. The gearbox works fine up and down through the gears except there is a slight shudder at about 40mph. We have been quoted 1000 pounds to replace just the torque converter or 2400 pounds for a complete overhaul plus vat. What should we do?

Claudio on May 31, 2019:

My GM has always worked fine until this morning. Now at the present moment I started the engine and when selecting gears the car does nothing. Switched it off, allowed me to go back but no drive so I left it at home. I have a e39 530d touring.

Can you give me the real scenario I am facing

I have knowledge of how the tranny works, just in the selector shaft have a small leak behind the engine near the floor pans.

Is it low in ATF or the torque converter is gone?

I am from Portugal, we have a huge heat wave right now of over 33.C so I am puzzled why having this afternoon nothing to move the vehicle at my door step.

Percival Spence on March 28, 2019:

I have a BMW x3 with a GM 5L40-e transmission i am trying to get the neutral saftey switch and i cannot get the pin out even figure out how to remove the rod holding the switch could you please give me any assistance on how to do this?

Mohamed on February 02, 2019:

Dear sir

I have a problem in my car BMW e46 n42 318i 2002

The problem is that when I drive my car at after it’s been stop for hours , the first and second speed go fine, however, when it comes to the third speed the red cog light flash on the dashboard, which mean there is a problem in the transmission “gearbox 3”.

Some people told me that this happens because there is air leak in the vacuum lines. Others said that I have problem with the coolant system.

Can you please tell me what is the problem with this sort of car and what should I do.

Looking forward to hearing from you soon

Many thanks

Mohammed

Perry.morris482@gmail.com on January 19, 2019:

I own 2 CTS a 05 that I currently Drive as a everyday supposed to be dependable vehicle and an 03 cts I bought for parts since I have had to do transmission 3 * 2 * complete rebuild new case you converter everything I've done the rear end twice alternator 3 times with a new battery every time starter twice both front hubs multiple times drive shaft multiple times should have got a new drive shaft but can't afford some of the ridiculous prices Cadillac parts I really love my car I've had it five years but it has literally broke my bank I have two kids and a lovely wife that depend on me as much as I depend on this car and it's not panning out for me I would recommend not buying a CTS unless you were the owner of a second vehicle like my Trailblazer it drinks gas about 12 miles to the gallon but it always starts and I've literally done nothing to it a starter but I was able to just repair the brushes and I've been having problems with the sunroof we just don't use it no more I sure would love a new Cadillac but I am just sick to my stomach with all the problems I've had with this one maybe Cadillac will just give me a new one LOL

Alfio on December 20, 2018:

Hi, I have a GM Korea Chevrolet Captiva 2.2D 184 CV LTZ 4WD my2011 with AT model 6T45 sell/buy in Italy with a 1st rebuilt AT @ 80.000 km due to a brake wave plate and 2st rebuilt AT @ 92.000 km due to tempetature TCM 107 °C - fail safe mode - harsh shifting "3-4-3". TCM and valve body assembly aren't replacing yet, and I ask you how can i diagnostic the cause of the ultimate problems. Have a nice day, thanks A. Maderna

mrwrench on December 07, 2018:

Is it possiable to remove the bellhousing from my 5l40e without tearing the whole thing apart? I have the engine out so front of transmission is acessable.

Nathan on October 25, 2018:

Hi John I have the above gearbox in my e39 530d my question is should I change the ATF and filter? 175 k no issues.

BMW state sealed for life do not change the atf, also what’s the ATF spec? Many thanks in advance

Kavz on July 11, 2018:

Hi there what will cause a bmw e46 318i that is equipped with a gm5l40e trans to delay in 2nd gear...it pulls the rmps into redline but if u drive it tip shift it perfect and all the other gears up properly,could this be electronic related or mechanical?

willy TanDi on June 29, 2018:

My 2005 X5 e53 3.0l with VIN WBAFA11050LT56306 and M54 engine# 32255812306S3

and GM Hydramatic Transmission ( green colored engine metal tag).

My inquiry is what parts will I buy when a total transmission oil and service should be done.

Will the parts include these (like in ZF engine) 4 plastic tubes, 1 hard plastic bridge or goggle as they call it) , 1 large upper port inlet plastic, 1 filter.

Please give me guide assurance before I buy parts and proceed to BMW service. Its cheaper to outside then proceed to authorized BMW Servicing station.

John Bullock (author) from Yorkshire, England on June 11, 2018:

Hello laszlobal,

There are a number of places in the UK (still Europe...for now) that sell or recondition torque converters. Two companies that comes to mind are Autolink Automatics and The Converter Shop.

Kavz on June 07, 2018:

Hi what will cause a 5l40e trans to stall in first gear,seems as if two gears engaging at the same time....

laszlobal on May 26, 2018:

dear John, I send you this message from Saint Point, a small village in Burgundy, France, Europe...My friend whos is a talented mechanic has owns a 2003 BMW E39 530D and is looking for to buy (exchange) his out of service torque converter. It's almost impossible to source this part in Europe and I would like to help him. May I ask you what is your advice in term of parts sourcing? thanks in advance.

Peter from Brisbane on May 23, 2018:

Can I replace my 5L40 in my Range Rover with a 5L50?

John Bullock (author) from Yorkshire, England on April 10, 2018:

The 5L40-E does not have an internal temperature sensor; only speed sensors. The location of the sensor (if it has one) varies from vehicle to vehicle to vehicle, but is usually found somewhere along the transmission cooler path. Either inline with one of the pipes or on the radiator itself.

Craig on April 10, 2018:

I'm looking for the location of the oil temperature sensor

John Bullock (author) from Yorkshire, England on April 09, 2018:

Hello Craig. Sorry I'm not sure what you're asking. Are you looking for the location of the temperature sensor or where you can buy the sensor?

Craig on April 08, 2018:

I have a e39 BMW, I looking for the oil temperature sensor that fits inside the gearbox

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