clutch adjustment

[littlejim]

Now that Mrs LJ is well into the running in period for the new knee, I'm getting some TR4A time again. (Up until now I've been doing a pretty good imitation of the genie out of Aladdin's lamp.)

The gearbox is snugged up and I've just bolted the clutch slave cylinder on (again). This time it is a new one from Moss plus new activating rod etc.

 

The book says to screw the rod out until the 'slack' is taken up and back off 1/10th of an inch.

In my case I never get any slack; the spring inside the slave cylinder pushes the piston back and gets rid of any potential slack. (On the old one I hacked a bit off the rod to try to get some slack, but the piston beat me every time.)

 

I'd prefer to have a distance for the lever to move when the clutch is depressed fully, measured at the end of the lever or at the second hole in the lever, as this would be a bit more meaningful.

Anybody out there with the answer.

[vivdownunder]

Jim, first thing to try is a stronger return spring 027645 to overcome the slave cylinder internal spring, which keeps the rubber cup in place.

 

You must have some slack, or the thrust bearing stays engaged and will fail in short order.

 

Cheers,

 

Viv.

[littlejim]

Viv,

 

this might illustrate what I'm on about.

The piston pushed in as far as it will go.

Released. The piston hard up against the back of the slave cylinder. So the only time I would get any slack is when the piston is in this position, the rod is too long to let that happen.

I'm trying the LJ kludge which involves screwing the rod into the slave cylinder, flooring the clutch, then trying to turn the shaft coming out of the gearbox. Just getting a bit of movement(clutch slip) now. have to decide whether to use a 'slight graunching until it wears a bit' setting or a 'complete disengagement with later tightening up' setting.

 

I'm working on the possibly incorrect assumption that the master cylinder is doing its stuff correctly.

Edited March 23, 2011 by littlejim

[johnny250]

Jim, first thing to try is a stronger return spring 027645 to overcome the slave cylinder internal spring, which keeps the rubber cup in place.

 

You must have some slack, or the thrust bearing stays engaged and will fail in short order.

 

Cheers,

 

Viv.

 

 

Is that a fact Viv? Most bearings are designed to rotate constantly, is the clutch bearing different in that respect?

 

john

[vivdownunder]

OK Jim, let's have a look at this before you go berserk and burn the bloody thing.

 

Firstly, check at the pedal box. There must be a small free movement before the pedal starts to push the rod into the M/C.

 

Use the middle hole in the clutch operating shaft lever for the slave cylinder rod.

 

Adjust the slave cylinder rod - Haynes TR2-4A Workshop Manual page 116 tells how.

 

With everything at rest, grab the clutch operating shaft lever. Push it back. There must be be a small take up (nominal .010") before you hear the thrust race hit the clutch fingers.

 

If you can't get this essential clearance by adjusting the rod, then the rod has to be shortened. These days generic rods are supplied which don't always fit properly.

 

See how you go,

 

Cheers,

 

Viv.

[vivdownunder]

John, TR clutch release bearings need to disengage from the clutch fingers for a decent life span.

 

That's why it's not helpful to sit at a red light with the car in gear and the clutch depressed.

 

A TR clutch release bearing gets an intense side force loading on the housing.

 

By contrast, a roller (wheel) bearing has the inner and outer surfaces held static, with its loading is straight down onto the roller balls.

 

Regards,

 

Viv.

[littlejim]

I think I've worked out what the book means.

Screw the rod out until you can actually move it with your fingers (previously rock hard up against the piston) then add about a tenth of looseness.

Latest iteration anyway.