Supplemental Information & Instructions for 386-205 or MRD1299 Valve Lash Adjuster (Clik-Adjust)
All British Cars with Overhead Valves
The Clik-Adjust method of valve adjustment does not use a feeler gauge. Instead, the tool is used to tighten the adjusting screw until the gap between the rocker arm and the valve stem is zero. The adjusting screw is then backed off to the correct gap.
Backing off the adjusting screw will always increase the gap, and every degree of rotation will correspond to a precise increase in the gap. The relationship between a degree of rotation and the gap depends on the length of the rocker arm and the thread pitch of the adjusting screw. Note: Say you have two cars, one with BSF threads on the adjusting screw, the other with UNF threads. With BSF threads there will be fewer clicks for a given gap setting than it will be with UNF threads. This is an important distinction to be aware of if you have cars with different types of threads on their adjusters.
The magic of the Clickadjust is that it provides an audible click for every 1/30 (12° ) of rotation. For any given rocker arm and adjusting screw, a single click will represent a precise change in the gap. However, before you can use the tool, you must know how much the gap changes with a single click.
Calibrating the Clik-Adjust We will assume that the gap associated with a single click is unknown for your car.
Note: there are web pages that list this information, but in at least one instance it is incorrect. Don’t assume what you read on the web is correct- Calibrate! (Please note: Space for your calibration notes are on page 2)
Although a feeler gauge is not an accurate method of determining absolute gap with a worn rocker arm, it can measure the change in a gap very well.
• Rotate the engine until a valve is completely closed.
• Fit the appropriate socket (you have to provide it) for your lock nuts onto the Clickadjust.
• Position the Clik-Adjust on the adjusting screw of the closed valve, with the socket on the lock nut.
• Move the handle counterclockwise to loosen the lock nut on the adjustment screw. Press the built in screwdriver down and engage the slot in the adjusting screw.
• Set the Initial Gap: Insert a 0.010 inch feeler gauge (commonly called “10 thousandths” or “10 thou”) between the valve stem and the rocker. The actual thickness does not matter; we’re just establishing a flat surface to start from. Back off the adjusting screw (counterclockwise) if necessary
• Tighten the adjusting screw (clockwise) until the gap is zero (You will feel/hear a loud click).
• Leave the “10 thou” feeler gauge in place.
• Look up the Correct Gap – the valve clearance specifications for your car. In this example, we’ll say we need a 0.012 inch or “12 thou” gap. Find the appropriate feeler gauge.
• Using the Clik-Adjust, back off the adjustment screw (count the clicks!) until you can slide in the feeler gauge that matches the correct valve clearance. (“12 thou” in this example). For the purpose of this example we’ll say we heard 24 clicks.
• We now know the number of clicks that corresponds to the correct valve clearance.
Once the number of clicks for the correct valve gap is determined for a particular car, there is no need to calibrate again. You will have to re-calibrate for a different car, of course.
Your results will be different than this example! Write what ever you come up with in your workshop manual! You can also write the number of clicks on a piece of tape, and put it right on the handle of the Clik-Adjust.
Using the Clik-Adjust to Adjust the Valves
To finish our example, let’s say your workshop manual calls for 12 thousandths valve clearance.
You will tighten the adjustment screw until the gap is zero, than back off 24 clicks.
Note: The tool has TWO click mechanisms built into it. A "heavy" one identifies when the screwdriver has turned the adjusting screw enough to force the rocker arm down firmly against the valve stem. At this point a loud click is heard. The other click mechanism is a "light" one that sounds as the screwdriver is turned relative to the handle that holds the socket on the adjuster lock nut. These light clicks will be heard both when setting the gap and when tightening the lock nut. It is during the gap setting step that the number of clicks should be counted and are important.
After calibration, you know how many clicks it takes to set the gap on your car.
1) Rotate the engine until a valve is completely closed.
2) Fit the appropriate socket for your lock nuts onto the Clik-Adjust.
3) Position the Clik-adjust on the first adjusting screw, with the socket on the lock nut.
4) Move the handle counterclockwise to loosen the lock nut on the adjustment screw.
5) Press the built in screwdriver down and engage the slot in the adjusting screw. Tighten the adjusting screw (clockwise) until the gap is zero (You will feel/hear a loud click). The tool design prevents the lock-nut from restricting the movement of the adjustment screw, which might be mistaken for a contact between the rocker arm and valve stem.
6) Back off the adjusting screw (counterclockwise) until you hear the correct number of clicks. (the number of clicks you determined when you calibrated the tool) When the screwdriver part is being turned the tool's handle must be held perfectly still for maximum accuracy.
7) Hold the screwdriver part of the tool perfectly still and tighten the lock nut by moving the handle clockwise.
Rotate the engine until the next valve is closed, and repeat the process.
John ;-)
