Why you can’t hold a tune with the best of them…

Kahler tremolo systems are notorious for staying in tune no matter how you abuse them. That’s no lie. But heavy tremolo use and carpet bombing techniques can eventually wear down even the best metals. That is why ol’ faithful may not be so faithful anymore.

It’s called metal fatigue. That’s where most tuning problems can be found. Read on……There are 14 overall reasons but the  most common 3 are listed first.…

#1 reason:  String lock or locknut is grooved or worn out. 80 % of the time this is why when you pull back your strings go flat or when you divebomb and your strings go sharp.  This problem is most noticeable on pullbacks. Check the clamping plates and the string lock base for channels or grooves cut into the metal by the slipping strings. Replace if grooved. Also the nut must be lubricated with white grease. This prevents the winding from chinking back and forth over the nut during tremolo operation and creates a smooth slippery slot for the string to slide on. Graphite nuts work great but still lube them.

#2 reason: You need to put a 45 degree bend in the wrapped windings next to the ball end. This prevents the string from spinning in the string hook, and reseating due to string slack during deep dives. See picture.

#3 reason: Metal fatigued or rusty return springs. How can you expect it to return back to center if its got weak return springs?  Replace every 5 years of average use.

All 14 reasons: 1) The Bearing Bolts PN# 8390 or Bearings PN# 8313 are dirty and gummed up from years of oils and grime. remove and clean or replace if necessary.

2) It's possible that there is a notch worn in the Load Tension Leveler PN# 9404 pin hole. (it's hard to detect), and /or the Load Tension Leveler Pin PN# 8314 is bent or a foreign object is in there somewhere. Clean and replace these if they look bad.

3) The Normal Tension Return Springs PN# 8412 are fatigued and worn out. Replace them. If you desire you can upgrade to a Heavy Tension Springs PN# 8413 for a firmer feel similar to a Floyd Rose. Also you want to check to make sure the Spring Mounting Screws PN# 8392 are snug and tight. If they slip it won't return to center.

4) If your tremolo does not return to center ONLY after an Up Pull on the arm, then you might want to inspect the String lock to make sure one or more strings are slipping through the Clamp Plate PN# 9535. The strings eventually create a worn out channel dug out of the Clamp plate. If this happens it will change the tension over the entire cam and it wont center out correctly. Inspect them and replace if necessary.

5) If you have a bolt on neck. If it shifts when your playing, then you cannot keep it in tune. Test it by trying to knock it from the side to see if it shifts. Is the neck shimmed? If it is, the saddle rollers may be excessively high which can cause tuning problems, try lowering the saddle height adjusters.

6) Are the nut slots wide enough that the strings seat properly and do not bind? If any one string hangs up in the nut, it may not tune properly. Place a drop of GraphitALL on the string in question where it crosses the nut. Improved tuning means the nut was at fault. If necessary, widen the string slot without deepening it using a nut file, or continue to periodically oil the problem area.

7) Is the string lock screwed tightly to the headstock? If it is not, it may shift occasionally causing general tuning problems. Try testing it by placing your thumb and index finger on the sides of the string lock extending down onto the neck or headstock. Push the vibrato bar down as far as possible then pull it up as far as possible. If the string lock is moving or shifting positions, you may be able to feel slight vibration or movement. Sometimes you can even hear a faint "click" or "chink". double check and tighten all 4 string lock mounting screws PN# 8363, firmly.

 Is the string lock positioned at a suitable height in relation to the nut? If the string bends more than approximately 12 degrees as the string passes over the nut and into the string lock there may be a potential slack to accumulate between the nut and the string lock. Visually inspect and estimate the angle of the string bend with reference to a protractor. if necessary, raise the string lock with a flat shim PN# 8450 or a rounded shim PN# 8460 so that the angle of bend is reduced to less than approximately 12 degrees. Test it by depressing the arm and releasing it. Then tune the guitar. Make sure the string lock is locking to the best of your ability. With the vibrato arm depressed fully, push on the strings between the string lock and the tuning machine heads. Release the arm and check tuning. If any strings have gone radically sharp they aren't being clamped tightly enough.

9) Is the string lock gripping all the strings? If not, one or several strings may go sharp after the arm has been depressed, or flat after a string has been bent or the arm has been raised. Solution: For standard string locks: turn wrench harder. If this has no positive effect, remove the clamp plates from the string lock and file 0.020" off each end of each clamp plate. The reason the plates might need filing is that they must be able to tilt in order to make firm contact with two strings of different sizes. Shorter plates can tilt and still be long enough for even the widest string spacing. If the shorter plates still cannot tilt the clamp, screw holes must be enlarged with a round file or drill bit.

For deluxe string locks to function properly it must be lubricated. Remove the clamp screws, washers, and square wedges. Smear wax or grease (lip balm) on bottom of wedges and both sides of the washers and then reassemble. Smear lubrication on the lobes at base of the levers. Tighten the screws finger tight and back off 1/4 turn. Snap shut the levers. If they do not close with very firm snaps, open the levers and tighten the screws slightly. Repeat until the levers snap shut with good firm snaps. Do not use tools to force the levers closed.

10) Are the rollers rolling? If the rollers or a roller does not roll easily, the tuning of the unit can be greatly impaired because the roller will create drag on the string and cause either a slack build-up behind the roller, (resulting in tuning error for that string) or cause the entire unit not to balance accurately (resulting in general out of tune result). To test this, remove a string to the side of the roller and rotate the roller with your finger. Replace the string onto the roller and move the tremolo arm up and down. Does the roller appear to roll? Solution: If a roller is stuck try to work it free with your finger. Then apply a drop of 3 in 1 oil or sewing machine oil to each side of the roller between the roller and the inside edge of the saddle fork. Sometimes if a roller has a flat spot which has been cut into it by the string it will turn freely under finger pressure but will not turn when the string is in place and the vibrato arm is moved. If a roller will not roll beneath a string it must be worked lose until it rolls, or replaced.

11) Are the rollers too high? If the rollers are very high, they may be causing friction which is keeping the cam from balancing properly. When a roller is very high there is more pressure from the string exerted on the roller and therefore more friction between the roller and its axle pin. This friction is often the cause of general tuning problems and is very often the cause of the specific tuning problem which is that the strings tend to stay flat when the arm is pushed down and released and the strings tend to sharp when the arm is pulled up and released. High rollers are also often the cause of string breakage because of the increased angle of bend in the string and greater contact pressure. This breakage will occur at the roller. Visually look at the rollers from the side of the guitar. Do they appear to be set high? The optimum roller height for tuning stability is .350" to .400" (approximately 3/8ths of an inch). measuring from the top of the mounting ring to the string. This is how you can remedy the situation..........

Stud mount tremolos: If the string height above the neck is satisfactory make a mental note of its height. Then lower the saddles until the strings are about 3/8ths of an inch above the tremolo mounting ring. Next, raise the entire tremolo by turning the studs and front riser wheels until the string height above the neck is once again satisfactory. The tremolo base plate mounting ring (frame) should remain parallel to the plane of the fret board. On a guitar with a pitched back or angled back neck, raise the rear studs more than the front riser screws to tilt the tremolo until it is in a plane parallel to the fret board. A non-parallel condition between the fret board plane and the tremolo is especially common on guitars with carved or curved tops. The problem is that the bridge is tilted back to follow the sloping curve of the body and this has the effect of high rollers when the rollers don't appear to be high. In actuality the entire front of the tremolo is high. Therefore, the roller height measurement may be only 3/8ths of an inch yet this is deceiving since the top surface of the tremolo base plate mounting ring is itself high in front from being tilted.

Flat mount tremolos (on guitars with bolt on necks): Loosen the strings and detach the neck. If a shim was found in the attachment area nearest the bridge remove it and re-attach the neck. If no shim was found, add a shim of about .030" (1/64th of an inch) to the neck mounting surface in the area furthest from the bridge and re-attach the neck. If a shim was found in the area furthest from the bridge increase it by 1/64th of an inch and re-attach the neck. String and tune the guitar. The strings will now be too high over the neck. Lower each saddle until the neck action is good. The purpose of this is to tilt the neck so that the rollers can be lowered.

Flat mount tremolos (on guitars with permanent necks): Remove the tremolo from the guitar and reinstall it with a base plate mounting ring shim between it and the guitar body. Then lower the saddles to return the neck action to a good level.

12) Are the springs free from obstruction when the tremolo is in all positions? If the springs ever hit anything they can make audible noises and even cause turning problems. Solution: Deepen or widen the spring cavity to provide clearance.

13) Are the notches in the steel inserts riding on the very top edge of the mounting screws? If the notches ride lower on the shank or collar of the screw the entire tremolo will not balance properly and will therefore be frequently out of tune. Visually inspect them.

The fix would be to loosen the strings and raise the fulcrum base plate including the steel insert up so that the notches ride the top of the screw head. Retune the guitar.

14) Are the notches in the steel insert lubricated? If not, the balance will not be optimum and therefore tuning will not be optimum. Visually inspect them. If necessary, apply a drop of 3 in 1 oil to the point where the mounting screw heads meet the notches. A smear of grease works well in addition to the 3 in 1 oil.