TR6 TR250 TR4A Clutch Components
TR’s are known for clutch problems.
As with any car, time and mileage take their toll. Clutch disc linings wear with use and pressure plate diaphragm springs get ‘tired’.
When your clutch wears out we strongly recommend that all related parts be carefully inspected and replaced as necessary. Doing this will reduce the likelihood of ending up with an unsatisfactory job and all the frustration that goes along with it, such as pulling everything apart a second time. Clutch troubles can be either hydraulic or mechanical.
If your car begins to feel & sound as though it has an automatic transmission the probability is high that the clutch is worn out. If this happens to you the symptoms will be easy to detect:
Flooring the accelerator pedal while driving in first gear will cause the engine speed to increase almost instantaneously without a comparable increase in the speed of the car. This almost always indicates that your clutch is slipping and worn out.
On the other hand, if you press the clutch pedal and it feels mushy, or very little ‘effort’ is required to press the pedal to the floor, the clutch master or slave cylinders are probably faulty. A leaking clutch master or slave cylinder will cause the fluid level in the master cylinder reservoir to fall. The clutch system holds very little fluid. If the clutch master or slave cylinder leak, it will empty out your hydraulic system in no time. Once air gets into the system, the clutch won’t release at all.
TR6 & TR250 clutches are prone to a variety of troubles.
On occasion, car owners have replaced the clutch only to be plagued with ongoing clutch trouble. When this happens, it is not uncommon to blame continuing clutch trouble on a supposedly ‘faulty’ new clutch.
Below are listed a number of related clutch problems which we have experienced. If you have clutch trouble, all of these items should be carefully examined.
Clutch Release Bearing.
The clutch release bearing in these cars is a ball race type bearing. It is EXTREMELY sensitive to incorrect installation. There is a slight interference fit between the release bearing and the sleeve. Don’t be tempted to try installing it by hammering the two pieces together! Doing this will dent the ball bearings and the races. It will fail immediately once this is done… Failure of the bearing will be accompanied by squealing noises and damage to the release fingers of the clutch pressure plate.
To install a release bearing successfully, it must be gently pressed onto the sleeve using a press or a vice. During the installation process, pressure exerted by the press or vice, should be released and the bearing partially rotated. Repeat this procedure a number of times during installation. This is necessary to evenly distribute the pressure on the bearing balls during installation. Installing the release bearing in this fashion will substantially extend its service life.
Clutch Release Bearing Carrier/Sleeve
The clutch release bearing is a press fit onto its sleeve. The inner surface of the sleeve must be in good condition. It must slide easily on the outer surface of the transmission front seal housing. However, it must not be excessively loose and worn. If its internal bore has become badly worn it may ‘cock’ and bind when you are engaging the clutch. This can cause severe drivability trouble.
Replace the sleeve if it is in questionable condition.
Clutch Cross Shaft, Cross Shaft Fork, Locking Pin, and Fork to Release Bearing Sleeve Dowel Pins
Triumphs are notorious for problems in these components.
They all must be checked carefully! In particular, check the following:
Unscrew the cross shaft to fork retaining pin. At least 50% of the time the pin will prove to be broken. This will cause insufficient release fork travel, resulting in partial clutch release. If the pin is found to be intact, check that it still fits tightly in its tapered hole in the cross shaft. Any rocking between the pin and the cross shaft will soon result in a broken pin and symptoms as just discussed.
Even though no Triumph manual will ever tell you this, we strongly urge you to install a brand new tapered locking pin AND drill a second hole through the cross shaft & fork. Then install a large bolt and locking nut. This will prevent a recurrence of this extremely annoying (& labour intensive) problem.
Check the two outboard pins located in the ends of the cast iron fork. These pins communicate the movement from the cross shaft/fork to the release bearing sleeve. Originally these pins were round. Yours probably aren’t. Careful inspection will usually show these pins to be rather flattened on the side that bears against the release bearing assembly.
Wear in this area will effectively reduce the clutch linkage movement by 1/16″ or more. This is sufficient ‘lost movement’ to cause release problems in an already marginal clutch.
New pins are easily installed if necessary.
Bell Housing Bushes
The transmission bell housing supports the cross shaft in all TR6 through TR3 vehicles.
In each side of the bell housing, bushes are pressed into the holes through which the crossshaft passes. These bushes wear badly where they contact the cross shaft, particularly on the driver’s side.
Also, check the LH end of the cross shaft. It tends to wear badly as well.
Excess wear in either of these components further adds to ‘lost movement’ in the clutch linkage, contributing to clutch release malfunction.
These items are cheap, easy to install (during clutch overhaul), and we urge you to replace them.
TR6TR250TR4A Clutch Cross Shaft
Fits 6676 cars. CLSHAFT136354