How to troubleshoot clutch ram

If the gears of a manually driven SAM spreader are not meshing fully it is recommended that the clutch ram is examined.

On the spreaders, with manual drive and a stainless steel chain box, between 2004-2017 the 2.5" clutch ram was mounted under the box. The gears were pulled into mesh by the ram compressing.

If the internal piston (marked below) unscrews off the shaft the piston bottoms out before the spear has travelled its full stroke - hence the gears do not fully engage.

To check this the clutch rams must be pulled apart. This is done by:

1. Apply compressed air to the bottom port to lift the spear to its full extension.
2. Release the circlip on the top of the ram, lift this plus the washer & O ring out of the way.
3. Use a length of small pipe, or similar object, to push the centre of the ram back into the barrel by about 20-25mm.
4. This will expose a machined groove in the inside of the barrel.
5. In this groove is a sprint wire clip that must be removed.
6. Once this is done the internal part of the ram can be removed from the barrel.
7. Ensure that the bottom screw on piston is screwed up tight.
8. Once this is done use a centre punch to mushroom the bottom of the shaft to prevent it unwinding again.
9. Reverse dismantling instructions to re-assemble the ram.