Jaeger LeCoultre 540 Repair Tips

Repair Tip and Dangers when repairing the Jaeger LeCoultre Atmos 540

Posted On 09/10/2018 By Jeff Hamilton
Jaeger LeCoultre 540 Repair Tips

Repairing your first Jaeger LeCoultre 540 and the pitfalls to avoid.
By Jeffrey Hamilton, Certified Master Clockmaker

*** Before you begin reading you can click on any of the images to get a larger view. You will need to click the back button after you have finished looking at the larger image to return to the blog. ***

It is very easy to see the difference between the Atmos 540 on the left and the Atmos 528 on the right. Many repairman have no problem servicing the Jaeger LeCoultre Models 519-528 but are not sure about the Model 540. If you are not aware of the design differences in the Model 540 you can make a very expensive mistake. Jeager LeCoultre did a complete remodel of the Atmos clock in 1985 and many things were changed but a few things remained the same. The only part that will work in all of the older models (519-528) and 540 is the suspension spring. The new style bellow (motor) that is used in the Model 540 will work in the Models 519-528 but the larger style bellow used in the 519-528 will not work in the 540.

The model 540 bellow (motor) is held in place by a bayonet style locking system. By turning the bellow housing clockwise it will unlock and can be easily removed for inspection.

Jaeger LeCoultre 540

To remove the minute hand the normal hand puller for older Atmos models will not work. The Model 540 requires a hand puller with a longer pin so it can reach to the end of the pivot. If you don't want to by a new hand puller you can cut a small piece of pivot wire (make sure ends are smooth) and drop into the center of the minute hand to make up for the extra depth then use you older hand puller to remove the minute hand. The hour hand of the Atmos 540 is often put on very tight and snaps in place. I use a pair of lifting levers to gently pry up the hour hand taking care not to mar the surface of the movement.

Atmos 540 Repair

Remove the dial and dial pan as you would on the Models 519-528

Atmos Hand Puller

This is where many service people make a major mistake. If you are new to repairing the Atmos model 540 I highly recommend removing the backspring BEFORE dismounting the movement. Count your links that are hanging out past the locking plate and make a note so you know what link to use to lock the backspring when you reassemble the clock.

Jaeger LeCoultre backspring

If you do not remove the backspring there will be tension between the clickspring and the winding gear on the back of the movement and when you remove the movement the clickspring can be damaged and if it is damaged it will make winding the clock very difficult.

Atmos Repair Tips

In this picture you can see the bellow housing has been removed, the backspring has be removed, the winding chain the hanging free and there is no tension between the clickspring and the winding gear. The movement is now safe to remove.

Atmos 540 chain

There are two screws holding the movement to the base. Be careful when removing these two screws many have a small lock washer and they can easily be lost. Also be careful because the movement can fall off after the screws are removed.

Atmos movement screws

This is the part that can be damaged if the movement is removed while the backspring is still in place. The 4 fingers of the clickspring can lock into the winding gear and be pulled forward and stretch out as the movement is removed. The part is sold as a complete assembly and is hard to find and very expensive if you do. This is also a part that should be removed and cleaned. I have found several clocks that the winding assembly is very gummy and will barely turn.

Atmos click asseambly

Here is the winding assembly removed from its post. Notice the clickspring fingers are not deformed and after cleaning this part can be returned to service.

Make sure to polish the roller and spin it to verify it spins freely and does not come to a sudden stop. If the roller comes to sudden stop it will need to be removed and cleaned. I will cover that in a different blog. Also verify the roller spring is on the roller pin and is not touching the balance tube.

Cleaning Atmos clock parts

I let the power down on the movement by holding my finger on the winding gear as I remove the click spring. After the spring is removed I slowly let the mainspring unwind under my finger.

Atmos Repair Tools

Make sure to remove the hour tube bushing. If this part is not removed after you clean the movement the cleaning solution be left behind and gum up the hour tube.

Cleaning the mainspring is one of the hardest jobs you will tackle in this repair. Before trying to remove the mainspring to clean it make a note of the direction it is installed in the barrel. No matter how careful you are trying to remove the spring more than likely this is what you are going to end up with. The Jaeger LeCoultre Model 540 mainspring is reverse wound and when it is removed it coils in on itself.

JaegerLeCoultre Mainspring

The most IMPORTANT thing is to be VERY CAREFULL when handling the spring so you don't break off the end bridle. It is welded in place and it doesn't take much to break it off. Clean the spring with OneDip and oil it lightly with a fine watch oil. Many people say these spring should not be oiled, but I have found them oiled from the factory so I oil mine.

Atmos clickspring assembly


All gears must be placed before the top plate is installed. The intermediate wheel will be installed after the plates are together.

Atmos movement assembly

Make sure the hour wheel and hour wheel bushing is installed before mounting top plate. Be very careful when placing pivots in jewels, they are very small and can be easily broken. Before tightening screws make sure all pivots are in their pivot holes.

Atmos hour tube

To reinstall the intermediate wheel I have make a small brass shim with a mainspring soldered on top that fits smugly under the 3rd wheel so that when I am driving back on the gear I do not damage the jewel in the back plate.

Atmos gear installation

Other problems you might encounter
• Broken balance tube: If the balance will not stay in poise you may have a broken balance tube.
• Lose screws in locking mechanism: Make sure all the screws are tightened on the movement. I have found screws that hold the locking mechanism together very loose when the clock comes in for repair and if not tightened this will cause the movement to move freely and not lock securely.
I hope you find this article helpful in repairing the Jaeger LeCoultre model 540. The Jaeger LeCoultre Atmos clock is not a clock that should be attempted by a novice repairman. Good quality tools, a steady hand and years of experience repairing clocks is a must before tackling any Atmos clock repair. If you break anything on the Atmos clock parts are very hard to come by and for the model 540 they are very very hard to find.

Jeff Hamilton, Certified Master Clockmaker
Tallahassee, FL
Owner : www.Atmostools.com and www.clockmaker.com

About The Author: Jeff Hamilton
Certified Master Clockmaker
Jeff Hamilton, Certified Master Clockmaker
Copyright Jeff Hamilton, 2018