When the gearshift is in neutral, does the engine also turn when pushed?
Hello Tony. Thanks for your comment. I tried your suggestion but the clutch will still not engage any where along the pedal travel. I adjusted the push rod clearance a couple of times (less than 2mm and more than 2mm) but could not find an engagement point.
I used a flexible iPhone camera to have a look at the release bearing. Not too clear. But the push rod the arm & release do not move much along the spine circa 3mm.
I tried to push the arm to deflect the springs but these were too stiff . I am going to ask my wife to press the pedal later so I can look to see if the springs are deflected by the pedal
I noticed that when I tried to push the gear stick into first with clutch pedal fully pressed that the car crept forwards very slight even though not engaged into first.
Hello SENC
With the engine off I can push the gear stick into 1st, 2nd,3rd etc with out the clutch. Engine turns when pushed. If I slide it back into neutral the engine does not turn when pushed. This says to me that the gearbox is fine and the problem lies with clutch mechanism.
When I reinstalled the gearbox and engine. I refitted the existing clutch disk and pressure plate assembly. There was very little wear on these. I replaced the release bearing and springs/clips.
Hi,
Something simple to check. When the clutch pedal is depressed you should have between 13 and 15 mm movement of the slave cylinder rod. If you have less than this, say less then 10mm, you have either..
i) Air in the system
ii) Fubar master cylinder
iii) Fubar slave cylinder
cheers
Mark
1 „Gefällt mir“
Or a cracked fork that is flexing.
1 „Gefällt mir“
Scot
When you installed the new springs and thrust bearing did you check the arm for any cracks, secondly did you measure the thickness of the two release bearings to make sure the new one is correct for the clutch.
I think you need to jack up the car and check the movement of the arm and push rod into the slave cylinder. But disconnect the battery first to make sure the car cannot move when doing the check. At the same time get your wife to very slowly push on the pedal to make sure the push rod is operating in the centre of the slave and not going in at an angle. Use a rule to check the operating distance by taking a measurement from the slave cylinder mounting hole to the operating arm, both with the pedal pushed right down and in its free position. Remove the slave outer spring and try moving the arm when the bearing is against the clutch and when it is furthest away from the clutch and again measuring both distances. So in effect we are trying to see if the slave cylinder is moving the thrust bearing far enough to disengage the clutch, or possibly that the thrust travel is too much before it engages with the fingers on the clutch.
Trying to get a light inside the bell housing is awkward but can you try and see what is happening to the arm when the pedal is down, does it flex or can you see ang cracks.
Tony
1 „Gefällt mir“
I have a spare release arm and pivot assembly so I’ve conducted a rather basic experiment by clamping the pivot in a hand vice, attaching a pencil at each end (perpendicular to rod and bearing centres) , and then putting the whole thing on a sheet of paper. Using Mark’s numbers, if I move the slave end 15mm I get (roughly) 11mm at the bearing end. If you do have a boroscope to see inside the bellhousing, and you’re getting, as per Mark’s advice, the 15mm rod movement, then you hopefully have 10/11mm at the bearing. If you’re only getting 3mm at the bearing then, in theory, there should only be something like 5mm at the rod.
I know it’s not a very scientific method that I used, but it could be another useful check.
Mike
Hello MikE
This was a really useful experiment. I am getting 10mm rod travel. I could see the release bearing deflecting the diaphragm springs/leaves. I didn’t pay attention to how much.
The bearing was deflecting less than the 10/11mm you measured.
The 3mm I referred to previously was the play in the release bearing when I fully loosened of the nuts on the rod.
I reduced the 2mm rod tolerance gap to zero with the release bearing touching the clutch plate but the clutch still did not engage.
Both of the slave cylinders I have used (old and new) produced 10mm of rod travel. So looks like I will have to bleed the system again.
Scot
This is probably correct as the pivot point is not central. I would say that 11mm is fine. I calculated the ratio on an old post for a 5 speed box I was having grief with.
Cheers
Mark
Broken or damaged clutch arm aside, there will be mathematical clues. I am away so cannot help, but others may be able to measure the throw of their clutch arm/slave cylinder to compare.
This is from when I had grief with a 5 speed box, pivot point, arm, slave identical to a 4 speed.
Ok. So here is a photo that should explain how far the bearing can move. The movement ratio is 1.67:1
You can see from the photo how I worked it out.
So a 15,5mm movement of the pushrod gives around 9.25mm throw of the release Bearing. Pivot point being the screw driver.
I had a dragging clutch in a recent install. Ended up taking the engine out again and found that the bearing in the end of the crank had been damaged during the first install meaning it was dragging on the gearbox input shaft. Replaced the bearing and all hugga mugga.
Tim
The soft clutch has now been rectified.
- I used an external i-phone camera to have look at the clutch and release bearing in the bell housing as the release bearing was not sliding cleanly along the spline. This showed that the D link/clip (between the release bearing and fork arm) was probably not in its correct position.
- I took out the engine (again) last week and the D link/clip was tilted back. I pulled it square, after which the release bearing moved cleanly along the spline. Alot of work taking the engine out just for a simple fix.
- Maybe this got knocked out of alignment when i installed the engine the first time.
- I re-bled the slave cylinder while the engine was out.
Once everything in the engine bay was refitted and running, first gear finally engaged with the clutch pedal. I have not been out for a run yet as I have been working through a few minor oil, water and fuel leaks.
Thanks for everyone advice.
4 „Gefällt mir“