Posts Tagged ‘ Clutch ’

Clutch Withdrawal Mechanism

by Miller | January 22, 2009 | In Clutch | No Comments

Withdrawal Mechanism

This mechanism consists of:

— a forked lever, integral with a shaft (passing through clutch housing) on which the outer operating lever is keyed;

— a return spring, connected to outer operating lever and anchored on gearbox casing. When in normal position, this spring keeps the central thrust carbon ring away from withdrawal levers carrier ring. The carbon ring is pressed against carrier ring by the throwout ring connected to forked lever.

Clutch pedal must have a free travel of 1 ³/₈” to 1⁹/₁₆” (35 to 40 mm). Should any correction be required, turn in or out the release lever control tie rod, which is adjustable.

After adjustment, lock by nut and jam nut

clutch throwout mechanism

clutch controls and adjusting mechanism

The Clutch Drags

by Miller | January 21, 2009 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #6

The Clutch Drags.

POSSIBLE CAUSES	REMEDIES
1) Excessive pedal free play.	1) Set free play at 1^3/8” to 1^9/16” (35 to 40 mm)
2) Driven plate warped.	2) Set level of driven plate, if possible. Maximum plate runout: .0118″ (0, 3 mm).
3) Roughness on driven plate facings.	3) Rub facings with a metal brush or replace them, if necessary.
4) Driven plate facings improperly fitted, loose or broken.	4) Replace facings. Facing rivets should be clenched, to avoid damage to pressure plate and flywheel.
5) Driven plate hub forcing on clutch shaft.	5) Locate cause of trouble and remove it, if possible. Otherwise replace the driven plate.
6) Damaged clutch shaft splines prevent the driven plate from sliding.	6) Replace the clutch shaft; also the driven plate, if required.
7) Oil or grease on driven plate facings.	7) Replace facings.

Clutch Excessive Facing Wear

by Miller | January 21, 2009 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #5

If your Experiencing Excessive Facing Wear.

POSSIBLE CAUSES	REMEDIES
1) Insufficient pedal free play.	1) Set clutch pedal free play at 1 ^3/₈“_to 1 ^9/₁₆” (35 to 40 mm)
2) Driver steps unnecessarily on pedal; this causes facing wear and damage to throwout ring.	2) Advise driver to discontinue wrong practice and step on clutch pedal only when necessary.
3) Pressure springs weak or broken.	3) Check pressure springs for tension and replace springs, if they are unserviceable.
4) Driven plate facings installed incorrectly.	4) Replace facings by new ones and install them correctly. Check driven plate for center.

Clutch Specifications

by Miller | January 21, 2009 | In Clutch | No Comments

CLUTCH SPECIFICATIONS

(See Exploded Clutch View)

Type …………………………………………	Single plate, working dry
Driven plate with facing of …………………….	Ferodo
Facing O. D. ……………………………………	5.51″ (140 mm)
Clutch springs:
Part No. ……………………….. Wire diameter ………………… Spring O. D. …………………… Number of working coils …….. Total number of coils ………… Free length …………………… Seated length ………………… Corresponding load ………….. Minimum load ……………….	891312 .1102″ ( 2,8 mm) .9134″ (23,2 mm) 6 7^1/2 1.6417″ (41,7 mm) .9646″ (24,5 mm) 51.80 + 2.65 lbs (23,5 + 1,2 kg) 43 lbs (19,5 lbs)
Lever carrier ring springs:
Part No. ……………………………………… Wire diameter ………………………………… Spring O. D. …………………………………. Number of working coils ……………………. Length, taut spring under 1.1 + .11 lbs (0,5 + 0,05 kg) of load Mounting length ……………………………… Corresponding load……………….. ……………	891319 .394″ (1 mm) .3740″ (9,5 mm) 10 ^1/2 .7677″ (19,5 mm) 1.1811″ (30 mm) 4.85 + .44 lbs (2,2 + 0,2 kg)]
Pedal free travel ……………………………………	1 _{3/8 ” to}1 _9/16″(35 to 40 mm)
Driven plate facing max. permissible out-of-true ……..	0059″ to .0115″ (0,15 to 0,30 mm)
Clearance between clutch shaft and clutch hub splines:
Longitudinally ………………………… Crosswise ………………………………	.0020″ to .0039″ (0,05 to 0,10 mm) .0059 to .0118″ (0,15 to 0,30 mm)

Clutch Removal and Instalation, Servicing Instructions

by Miller | January 15, 2009 | In Clutch | No Comments

CLUTCH SERVICING INSTRUCTIONS

Removal and Installation.

To remove clutch from car, first disconnect gearbox from engine and then take off the screws securing clutch to flywheel.

This also frees the driven plate.

To install clutch on flywheel, use as a guide flywheel locating dowels.

Prior to tightening down clutch mounting screws, align driven plate.

(pic. installing the clutch on flywheel using pilot to center the driven plate)

Pilot Bushing.

Whenever clutch unit is disassembled, it is essential to check that pilot bush on crankshaft for,

- clutch shaft rear support

- is not damaged or excessively worn.

Clutch shaft tang on bush end must also be found in good condition.

Max. clearance between clutch shaft tang and bush must not be greater than .0059″ (0,15 mm), otherwise pilot bush must be replaced.

(pic. clutch assembly installed on engine)

Disassembly.

Unhook the withdrawal lever carrier ring springs and take out the ring.

Unscrew the withdrawal lever fixing nuts on bolts and remove the levers and washers; slacken gradually the three T-handles to relieve pressure of clutch springs.

Next, take off clutch cover, springs and lever mounting bolts.

(Pic.location dowels on flywheel for clutch centering)

Pressure Springs.

When servicing the clutch, always check springs for perfect efficiency. In case springs are excessively weak - i. e., the spring length of .9646 (24,5 mm), corresponding to the actual assembly value, is obtained with a load of less than 43 lbs (19,5 kg) - replace the springs.

(Pic. pressure spring specifications)

Withdrawal Lever Carrier Ring Retaining Springs.

The length of closed springs, under rated clutch load, is .7677′ (19,5 mm), while the length of expanded springs (under a load of 4.85 .44 lbs -2,2 ± 0,2 kg) should be 1.1811″ (30 mm). If an excessive weakening of springs is noticed, replace the springs.

(Pic. withdrawal lever carrier ring retaining spring specifications)

Withdrawal Levers.

Check the withdrawal levers and their bolts for excessive wear, and replace [More]

The Clutch Slips

by Miller | December 18, 2008 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #4

When The Clutch Slips

POSSIBLE CAUSES	REMEDIES
1) Insufficient clutch pedal return travel, due to the flexible cable being stuck or the pedal return spring being too weak.	1) Locate cause of failure and replace spring or eliminate sticking of control cable.
2) Damaged throwout mechanism.	2) Overhaul throwout mechanism; also clutch, if required.
3) Clutch pressure springs weak or broken.	3) Overhaul clutch and replace springs.
4) Oil or grease on driven plate facings.	4) Remove cause of oil leakage and replace facings, if they cannot be reconditioned by rubbing with turpentine and metal brush.
5) Driven plate facings worn or burned.	5) Replace facings.

Noises when Clutch Pedal is Released

by Miller | December 17, 2008 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #3

If you Experience Noises when Clutch Pedal is Released

POSSIBLE CAUSES	REMEDIES
1) Misalignment of driven plate to flywheel causes slight movement of driven plate hub in respect of facings. This noise is particularly audible with engine idling or running at low speed.	1) Set level of driven plate. With driven plate locked on clutch shaft, set it under slight rotation and check for no runout in excess of .0118″ (0, 3 mm), using a scriber.
2) Insufficient pedal free play.	2) Set clutch pedal free play at 1³/₈ to 1 ^9/16 (35 to 40 mm)
3) Pedal return spring broken, weak or unhooked.	3) Replace the spring or hook it up carefully.
4) Forked lever return spring broken, weak or unhooked.	4) Replace the spring or hook it up and check for correct position.

The Clutch Grabs

by Miller | December 17, 2008 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #2

If The Clutch Grabs

POSSIBLE CAUSES	REMEDIES
1) Oil or grease on flywheel, pressure plate and driven plate facings.	1) Remove cause of leakage, clean flywheel and pressure plate thoroughly, replace driven plate facings.
2) Loose driven plate facings due to poor rivet tightness.	2) If facings are not worn, replace defective rivets. Otherwise, replace facings and clench rivets securely.
3) Driven plate hub does not slide freely on clutch shaft.	3) Remove any foreign matter or dirt deposits from shaft splines. Should trouble still be present, replace damaged part.
4) Pressure plate deeply cracked or broken.	4) Replace pressure plate.
5) Improper adjustment of withdrawal levers.	5) Adjust withdrawal levers as specified, under <<Assembly and Adjustment of Clutch>>.
6) Misalignment.	6) Locate the defective point and, if possible, reset alignment or replace distorted parts.
7) Stiffened throwout mechanism.	7) Locate stiff point and replace parts, if necessary.
8) Driven plate facings worn out.	8) Install new facings and make sure that the driven plate, pressure plate and flywheel are not damaged.

Introduction to the Fiat 500 Clutch & Exploded View

by Miller | October 17, 2008 | In 500 Workshop, Clutch | No Comments

Lets learn a bit more about the Fiat 500 clucth.

The clutch is a single disc design and incorporates a driven plate ( which carries the friction materials on each side) and a pressure plate and cover assembly. On early cars the pressure plate is tensioned by coil springs and the pressure is taken off by a central release ring linked to three release lever which pivot on the cover.

The clutch operating lever pivots in the forward end of the gearbox casing and thrust bearing on the inner end bears on to the release ring when the arm is operated. The operating arm is moved by a cable from the [More]

Noises When Clutch Pedal is Depressed

by Miller | October 17, 2008 | In Troubleshoot Clutch | No Comments

CLUTCH TROUBLE DIAGNOSIS AND CORRECTIONS #1

If your Experiencing Noises When Clutch Pedal is Depressed

POSSIBLE CAUSES	REMEDIES
1) Throwout thrust sleeve or ring excessively worn damaged or broken.	1) Replace sleeve and ring.
2) Seizure of thrust ring and withdrawal levers.	2) Replace thrust ring. Clean lever ends with metal brush and smooth out bearing contact faces with felt polishers.
3) Insufficient pedal free play.	3) Set pedal free play at 1 ^8/8” to 1 ^9/16″ (35 to 40 mm). To do so, work on withdrawal lever control rod as directed on page 94.
4) Pedal return spring broken, weak or unhooked.	4) Replace spring or hook it up and check for correct position.
5) Forked lever return spring broken, weak or un- hooked.	5) Replace spring or hook it up carefully.
6) Excessive play of driven plate hub to clutch shaft causes rattles.	6) Replace the driven plate and check that clearance between hub of new driven plate and clutch shaft is within .0039″ (0, 10 mm) endwise and .0118″ (0, 30 mm) crosswise. Should clearance exceed above limits, replace also the clutch shaft.

Fiat 500