The Dnepr Clutch

The Clutch Disk Assembly and Mechanism

  The dry double-disk clutch is designed to transmit the torque from the engine to the gearbox, to disengage the engine from the gearbox when changing the gears, and to ensure smooth engagement during the getaway of the motorcycle. 

   The clutch consists of driven and driving parts and clutch release mechanism.  The clutch driving parts include a flywheel and pressure, intermediate, and bearing disks mounted on the flywheel pins. 

   At the centre of the pressure disk is a square hole into which the clutch release rod enters. 

   The bearing disk is fastened to the pin ends with screws which are locked by prick punching (peening) the bearing disk into the slot of the screw head.

   The clutch driven parts comprise two driven disks having, on either side, molded-on linings made from friction material:  the disks move into mesh with the splined portion of the gearbox primary shaft.

   If used correctly, clutch service life will increase considerably.

   Take care not to ride with the clutch slipping.  When starting the motorcycle and shifting gears the clutch should be engaged gently.  The sharp engagement of the clutch with the engine running at high speed not only results in accelerated wear of the friction linings but also overloads the transmission components and increases the wear of the tires.

   The clutch release cable (clutch wire rope) tension is so adjusted with the aid of an adjusting screw so that the clutch release lever (left lever on the handle bar) free travel measured at the lever end is from 5 to 8mm.  With this free travel of the lever the clutch will be engaged fully (will not slip).

   The clutch has two linkages:  the clutch operating lever arranged on the handlebar (hand drive), and the shift pedal (foot drive). 

   When using the hand drive, throw out the clutch before the gear is engaged (or changed) and smoothly release the clutch operating lever after engaging the gear. 

   When using the foot drive, (Dneperglide) the clutch is disengaged automatically in the process of engagement (changing over) of the next gear without acting on the manual clutch operating lever. 

   In this case, after engaging the gear, hold the pedal with the toe and heel of your foot, gradually returning the pedal to the initial position and at the same time increasing the engine speed.

Adjusting the Dnepr Clutch

   The clutch release drive is to be adjusted as required with the aid of an adjusting bolt and adjusting screw on the clutch cable assembly.  First adjust the foot drive.  If the latter is properly adjusted, there must be a small clearance between the end of the adjusting bolt and the intermediate rod.  The presence of a clearance is indicated by the rocking of the shift pedal. 

The free travel of the shift pedal front arm must be within 10 – 15mm.  The amount of slide block travel, with the clutch disengaged manually, must not be greater than value of the slide block travel during clutch disengagement with the shift pedal.  To check the hand drive for correct adjustment, proceed as follows:  by depressing the shift pedal (up to the stop) with your foot, perform full engagement of the required gear.  Withdraw the clutch operating lever manually towards the handle on the handlebar.  Perception of cable tensioning is bound to appear only at the end of lever travel (at a distance of 1 – 5mm from the handle).  If this distance is found to be greater or less than specified, then turn back or forward the adjusting screw, ensuring the required value.

   After adjusting the clutch drive, tighten up the adjusting bolt and adjusting screw with lock nuts.

Removing and Installing the Clutch

   To remove the clutch without any special tools, proceed as follows.  First you need to disconnect the clutch cable from the outer clutch release lever by loosening the locking nut, and backing off the clutch cable adjusting screw.  Once you have enough slack, you can loosen the cable barrel from the lever.  You can now remove the lever pivot and remove the clutch throw-out lever. 

   Depress the clutch release rod front end and take out the slide, thrust ball bearing, rod end and rod.

   Once the parts have been removed they should be washed and inspected for excessive pitting, damage and signs of wear.  The bearing should be inspected thoroughly.  Any damaged or worn parts should be replaced. 

   The assembly should be done thus. 

   First you should fit the rod end, bearing and slide with the rubber ring into the input shaft.  Next you put the clutch throw-out lever onto the gearbox cover, pit the pivot into place and cotter pin it.  Screw the adjusting bolt into the lever lower end, and insert the clutch release rod with the rubber gland in the input shaft bore arranged in its front so that the rod extends over the shaft by 50 – 60mm.

   When mounting the gearbox into the engine, put the rod into the clutch pressure plate square opening and, thereafter, couple the gearbox with the engine and attach it together as required.  Adjust the gap between the adjusting bolt ball-shaped end and the mid rod, the gear shift pedal front arm release travel being 10 – 15mm.

   The MT-10-36 manual describes the process using a device.

   Insert a screwdriver into the slot of the screw securing the bearing disk of the clutch and, tapping the screwdriver with a hammer, drive off the disk metal drawn into the screw slot;  put on the device and release the clutch.  Next you should screw out the screws that are being used to secure the pressure disk, loosen the clutch and remove the device.  You are now ready to take out the clutch disk and springs. 

   After disassembling the clutch, wash and inspect the parts and perform the required measurements.

   The clutch is assembled in the following sequence.

   Insert springs of the same color code into the flywheel sockets.  (If you do not have coded springs be sure that all your springs are of the same tension.)  Put the pressure disk on the flywheel pins and make sure that the bearing faces of the springs have got into corresponding recesses in the disk.

   Install in place the clutch driven disk, intermediate driven disk, second driven disk, and bearing disk.  Install the driven disks so that the entry chamfer on the hub spline faces the gearbox.  Now insert the splined mandrel of the device, having registered the holes in the driven disks and pressure disk of the clutch.  Now you can put on the device and compress the springs.

   Having registered the holes in the bearing disk with the holes in the pins, screw in the screws securing the bearing disk.  Tighten the screws in a diametric (crosswise or star pattern) sequence.

   Remove the device, and peen each screw in two points, drawing the disk metal into the screw slot.

Tolerances

Rated Sizes, Tolerances, Clearances and Interferences in the Mating Parts of the Clutch