450 STEERING PROBLEM

[DDSSTONY]

I HAVE A 450 CRAWLER LOADER WITH BACKHOE. AS OF 2 MONTHS AGO IT STOP TURNING LEFT. MY QUESTION IS DO THE STEERING CLUTCHES PREVENT YOU FROM STEERING, OR WILL THE MACHINE DO CIRCLES IF THE LEFT CLUTCHES ARE BAD. THANKS

[Gil]

There are two things associated with the track drive on each side of the crawler. A clutch and a brake. When the left steering lever is pulled back, first the left clutch decouples the power from the left track. The left track will roll if the crawler is moving, but will not be under power. So if the right side track is still under power it will move the crawler forward, but the right track will dominate and tend to move the crawler in a large circle to the left.

As the left steering lever is pulled farther back, the left brake actually stops the left track from turning (the clutch still has the power decoupled). Now if the right side track is under power it will turn the crawler in a sharp turn to the left. When the left steering lever is released, first the left brake is released and then the left clutch engages the power to the left track. That is what happens when everything is working well.

There are four things that can go wrong. 1) the clutch can become stuck and not release to disengage power, 2) the clutch can slip and not engage full power, 3) the brake can stick or drag and keep the track from turning, 4) the brake can slip and not stop the track from turning. Combine this with the fact that some of the same four things can be happening on the other side of the crawler; and the fact that these conditions are not all or nothing, for example, a clutch can slip just a little or only when it is hot. There are a lot of possible combinations and you have to logically figure out which ones could cause the problem you are experiencing.

For example, if you pull full back on the left steering lever and your crawler moves in a circle to the left, you know that the RIGHT clutch is engaging and that the RIGHT brake is releasing. If you do this and the crawler turns sharply to the left, you also know that the left brake is engaging. If when you then release the left steering lever and the crawler goes back relatively straight you know that the left brake is releasing. You still don’t know too much about the left clutch.

When you pull back on the left steering lever, if the left clutch is not releasing there will still be power to the left drive sprocket. As you pull further back on the lever, the left brake will grab and the crawler will turn left but you should hear the engine strain or stall because it is still trying to turn the left sprocket since the clutch did not release, but you are holding it back with the brake.

If the left clutch is not engaging you won’t notice anything different when pulling the left steering lever, but when you release the lever, the slipping clutch will not apply full power to the left track. The right track will dominate and you will always go in a wide left arc. The problem will come when you try to turn RIGHT because if the left clutch is slipping it will not deliver full power to enable the left track to drive the crawler around to the right. Try driving the crawler up a slight slope when testing these things out so that you can be sure that it is the engine power which is keeping each track moving and not just downhill gravity.

Boy that was a long winded explanation! I hope it helped. Merry Christmas.

[DDSSTONY]

THANKS FOR YOU PROMPT RESPONSE. I LOOKS LIKE I NEED TO DO SOME SERIOUS IVESTIGATING IN THE SPRING. I PURCHASED THIS MACHINE TWO YEARS AGO. IT HAS A NEW JOHN DEERE TURBO DIESEL, THE POWER IS INSANE. THANKS AGAIN