Suddenly the clutch won't disengage

Cooper99

Cooper99

Member
The Rover season has not started well for me this year =( The latest problem is:
I have problems with the clutch on my 2200TC -74. The clutch pedal has not had any real vigor in recent 200 miles, and for about 50 miles I began to notice that the clutch is not fully released, and it became harder and harder to get in the gears. In the end it was impossible to get in the gears at all. Since the pedal felt soft / strange I suspected that the slave cylinder needed to be replaced which I did (but no leakage), and bleeded the system several times. Elasticity in the pedal then came back, and the push rod under the car moves fine. This should make both the slave and the master cylinder to be okay. The only problem is that the clutch still does not disengage; the gears can't get in. I can get it to reverse but not without scratch. If I start the car in gear and release the clutch it will judder/vibrate until the pedal is fully released and it is not possible to change to second gear (or another gear for that matter). What could the problem be? Misaligned pedal due to new slave cylinder? Something wrong in the clutch / gearbox leading to that the box needs to be taken out of the car? I have bleeded the system several times since I thought air could be the problem but it doesn't help, there is no air left.
 
Often when you fit a slave cylinder that prompts the master cylinder to fail shortly afterwards. IF you're certain that it is bled correctly and there isn't any air left in the system, (which you can't always see even though you can see through the pipe), then the first thing I'd check is the gearbox oil level, and then I'd make sure that all the clutch linkage is all set up as it should be.
 
Cooper99 said:
Okey, thanks for a quick answer. I'll check these things first.
Click to expand...

Setting all the clutch linkage correctly isn't quite as simple as it might seem, as you need to deviate from the factory recommended settings for the best result.
 
Cooper99 said:
Hmm, okey. Shouldn't I follow the instructions in the repair operation manual then?
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Not if you want the best result possible. If you want to do it, I'll talk you through it.
 
On the sticker in the engine bay it says that it should be SAE 20 oil for the gearbox, but in Sweden it is almost impossible to find such. At Rover Classics reference section it says that an "engine oil" can be used. What type of oil and viscosity are preferred for the manual box?
 
harveyp6 said:
Setting all the clutch linkage correctly isn't quite as simple as it might seem, as you need to deviate from the factory recommended settings for the best result.
Click to expand...

Come on then Harvey spill the beans; I've not heard this before.
 
pat180269 said:
harveyp6 said:
Setting all the clutch linkage correctly isn't quite as simple as it might seem, as you need to deviate from the factory recommended settings for the best result.
Click to expand...

Come on then Harvey spill the beans; I've not heard this before.
Click to expand...

It is on here somewhere, as I ran throught it a couple of times, once for Stan (Vaultsman)'s benefit before he put the LT77 in his, and someone else later. It's just better if it goes up when someone actually wants it as then it's fresh in the mind. I might try and find it.
 
pat180269 said:
Come on then Harvey spill the beans; I've not heard this before.
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You need some memory pills. I posted it up for your benefit....

viewtopic.php?f=1&t=15938&p=133269&hilit=one+spline+forward#p133269

:LOL: :LOL:

All I would add to that is that the pedal height should initially be set on the brake pedal, and then the clutch pedal be adjusted so that it's level with the brake pedal, but for all practical purposes setting the clutch pedal initially makes no difference, (especially if you're looking to cure a problem), you can just raise the brake to suit if required.
 
Now I have checked the oil and it turned out to be only half as much as it should be, but to refill with new oil in the right amount did not help to get the clutch to release completely. I also followed the instructions in the manual on adjusting the push rod and pedal. It did not help either; the clutch worked only worse.

So the problem remains, the clutch doesn't release completely when the pedal is maximally depressed.

While pedal pressure feels all right, the push rod under the car seems to move as it should, and there is no leakage from the master cylinder; could the master cylinder anyway be the cause? I don't think it could, but I would of course like to exclude hydraulic failures before I even start thinking of if it's worth the job to remove the engine and gearbox.
 
Cooper99 said:
I also followed the instructions in the manual on adjusting the push rod and pedal. It did not help either; the clutch worked only worse.
Click to expand...

Forget the book, do this.

harveyp6 said:
You need to set the drop arm on the box so that when it's pushed fully rearwards the bottom is one spline forward. Then set the brake pedal height so the bottom of the pedal is 6&7/8" vertically above the metal floor. Then set the clutch pedal height so it's level with the brake pedal. Then wind the pedal stop bolt all the way in towards the floor. Lengthen the pushrod on the drop arm, and than gradually shorten it until with the pedal on the stop, the piston is just touching the circlip in the slave cylinder. Then wind the pedal stop bolt up one turn, and check that you have about 25 thou between the piston and the circlip.
Click to expand...

Try that and see if it makes any improvement.
 
It seems like the pedal stop bolt on my car isn't the right one. It is an ordinary full threded "hex head bolt". Do I have to get a stop bolt with the original design? Can anyone post a picture of how it should look like?
 
Years ago when I replaced what I thought was a defective clutch slave cylinder on my MGB it turned out to be the rubber fluid delivery pipe. As you depressed the clutch the old pipe ballooned slightly thus causing the clutch to drag slightly as it by expanding it prevented full force being applied to the slave cylinder push rod.
I'm not familiar with the rover set up however.
Is that something worth considering
John Hoy
 
Now I've done the following adjustments:
1. Checked the drop arm, looks to be set correctly to around 1 spline (5 degrees according to manual), see attached photos: before pedal pressure (Fig. 1) and the pedal fully pressed down (Fig. 2).

2. Checking and adjusting the height of the brake pedal (about 167 mm from the floor), and adjusted the clutch pedal after the same height.
3. Adjusted stop bolt according to the manual and harveyp6 instructions.
4. Thereafter controlled slave cylinder piston travel. Without the pedal pressure the piston is 34 mm from the circlip, and with the pedal pressed down 18mm. Thus, the piston travel is 16 mm (since that is more than the 13 mm that the manual says, I suppose I don't have to adjust the pushrod to get the piston to nearly touching the circlip when pedal is pressed down).

Without too much hope, I started the engine and tried to get in the reverse; which I could'nt. I shut the engine, put in reverse and started again. I felt that the clutch was on a little bit, and when I released the pedal a few millimeters the car rolled back instantly. Tried to get in first gear, which was impossible. Shut the engine, put in first gear again and started, and the clutch was still not fully disengaged.

Thus, the adjustments don't seem to have any positive impact. What could the reason be that the clutch won't release fully?
 

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It sounds as though the pushrod under the car is too long.

You need to:

Make sure that with the drop arm pushed rearwards until it contacts the pressure plate, at that point the arm is one spline forwards. Not when it's at rest.
Set the brake pedal so that the distance from the very bottom of the pedal to the metal floor vertically is 6&7/8". Set the clutch pedal so that it's level with the brake pedal.
Screw the pedal stop bolt all the way into the floor.
Then adjust the pushrod length under the car so that when the pedal is on the stop, the piston in the slave cylinder is just touching the circlip.
Then wind the pedal stop bolt out one full turn and check that you have about 25 thou between the piston and the circlip when the pedal is on the stop.


If you do all of that and it's still the same then it could be that the bore of the slave cylinder is too large, although I doubt that as you seem to be getting the required amount of travel. Other wise it could be clutch spin or drag.
 
harveyp6 said:
Make sure that with the drop arm pushed rearwards until it contacts the pressure plate, at that point the arm is one spline forwards. Not when it's at rest.
Click to expand...
From the drop arms resting postion I only can push it one or two millimeter (=40-80 thou I think) rearwards until it stops. Then I can't push it by hand any further rearwards, and I suppose the drop arm then is in contact with the pressure plate (as Figure 1 above).
 
Cooper99 said:
From the drop arms resting postion I only can push it one or two millimeter (=40-80 thou I think) rearwards until it stops. Then I can't push it by hand any further rearwards, and I suppose the drop arm then is in contact with the pressure plate (as Figure 1 above).
Click to expand...

That's the point at which it should be one spline forwards, if that's the case then it's correctly set.
 
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