clutch problems

[straylight]

after a spirited drive through some hills and a slow return home on city streets, the clutch decided to stop working. Or more precisely, the pedal would only depress about 1/4 of the normal travel and just hit a solid block. As if someone had wedged a bolt at the end of the bell housing actuating lever or placed a brick under the clutch pedal. It just stops and the clutch is left engaged. The clutch normally disengages just off the floor.

Got her home (with a few 1st gear starts due to traffic lights) and back to the garage.

I've checked the actuating lever and it is not fouled externally, so I'm wondering what can have gone wrong. There is a slight move forward on the slave pushrod when the clutch pedal is pressed, until solid resistance means the clutch pedal can't be depressed any further. hydraulic blockage ? bell housing pivot rod ? master cylinder pushrod fouling ? The hydraulic level is good.

My next step is to jack the car up and see if I can lever the actuating arm on the side of the bell housing to try and track down where the fault is exactly, inside the bell housing or outside.

but before I start worrying too much, has anyone had this problem before ? any ideas ?

stu

[xvivalve]

I had this when the weld holding the external lever to the cross shaft had failed, also a similar symptom to when the wedgelok bolt fails...you might be able to diagnose by removing the slave pushrod from the lever and attempt to rotate the cross shaft by hand; normal operation would see some rotation up to the point of an audible 'ding' when the release bearing touches the fingers of the diaphragm spring...

[straylight]

thanks, so the critical symptom would be the clutch pedal goes in "all the way" without disengaging the clutch (as the wedgelok or lever arm breaks) and the slave rod is pushed too far out of the slave. On release and reapplication of pressure, the clutch pedal finds resistance as the slave rod now hits something that doesn't give.

I wish I could replay the exact sequence as the fault occurred, but this seems about right.

Either way that is a clutch out job to repair.

thanks Alun, excellent starting point. Glad it happened close-ish to home.

stu

[Jon Tilson]

As Alun has said you can get this sort of result from either failure mode.

I have never had the wedgelock bolt break but have had the outside lever weld come away on 3 occasions. What happens then is that the bent lever fouls on
the bell housing.

Removal will be an issue of the wedgelock has gone. You easiest removal sceriario is to cut through the pins or one of them on the release bearing carrier fork.

You can then rotate the fork forwards and drill through from the other side and push out the pin or what's left of it.

Time to maybe consider the sierra or SAAB style bellows internal slave cylinder. This is done on a lot of TR6's and other boxes to loose the wedgelock.

Jonners

[sprint95m]

Time to maybe consider the sierra or SAAB style bellows internal slave cylinder. This is done on a lot of TR6's and other boxes to loose the wedgelock.

Sierras have cable operated clutches. The concentric slaves sold for Type 9 conversions only work with certain applications.
The Saab concentric slave could be a contender given that Sprints and Saab 99/900 use the same clutch covers?
TR6 won't be suitable as is but no doubt could be adapted?

However there is one available off the shelf so to speak....
http://www.sprintspeed.co.uk/pages/prod ... ct-clutch/



Ian.

[Dolly-Nut]

I've had this multiple times now and it's always that weld breaking. Now I reinforce it before I install a gearbox.
If it is a broken weld pivot the box will need to come out to replace it however on my track car I successfully managed to bend it back and reweld and reinforce it and it never failed again. This would be a lot easier than removing the box and it should be possible with it in the car but you may have to remove the downpipe and transmission tunnel for access. Suitable crowbars etc should bend it back into place.

[straylight]

thanks guys, appreciate the quick replies.

looks like the sprint is off the road for a bit, probably around 3 months then. Priority is to build the new shed, then gearbox and bell housing out to effect repair.

I'll confirm the diagnosis and take some photos.

thanks again.

(damn)

stu

[Jon Tilson]

Depends on the Sierra....but I'm no expert.

Jonners

[Toledo Man]

I can confimrm that Ford Sierras did indeed have cable operated clutches. I had a couple of aftermarket cables snap in a short space of time. I bought a genuine Ford part and it lasted.

Getting back on topic, I reckon that the cross shaft is the best place to start looking. It is a known weak part of the Sprint clutch.

[straylight]

Almost embarrassed at how long it has taken me to get under the car and diagnose this problem, but now the car is in a clean shed with a decent amount of space and some other issues have died down a bit, I had a look.



seems the weld didn't so much crack as the lever.

I was hoping to be able to weld this up without removing the gearbox, but spac is limited and only one side of the lever is accessible, so it is gearbox out and weld up on a bench. I'm wondering whether to take out the whole engine (have hoist) or drop the gearbox. Probably go with the engine removal.

Good advice from everyone, a belated thanks

stu

[Jon Tilson]

A sadly common failing.

I have had one welded and its still going okay.

Have a look around and you can see some have gone for the internal bellows slave cylinder conversion.

I would swing out engine and box together. Downpipe flange is the worst bit of the job.

Jonners

[sprint95m]

I concur with Jon, take the engine c/w gearbox out.


That lever should weld okay.
Before putting everything back together I suggest you check the size of the clutch master cylinder, it needs to be 5/8" bore.




Fingers crossed, hope the tapered pin for locking the fork in position on the cross-shaft is fine.





Ian.

[Dolly-Nut]

I've done this several times now. It's worth welding an extra bit of metal on for strength.
My welded ones are still holding just make sure you bend them back in place accurately. I reckon it's possible to weld them in the car with the gearbox tunnel removed but I haven't tried it (yet!).
Last time I changed the gearbox and repaired the snapped one out of the car where access to both sides of the crack was more accessible. If you plan on removing the engine & gearbox together, personally I leave the downpipe joint well alone and split the next section down. For me they always slide in and out easily.

[straylight]

thanks guys, a job to do over the next few weeks then. Engine out.

[Pippin]

A sadly common failing.

Jonners

I had one gradually fail on my way home, although I didn't know what the problem was at the time. The gearchange became more and more difficult until, after stopping at a pedestrian crossing, I couldn't get it back in gear. I had to push it to the side of the road and later got a ticket for parking on the zigzags, because I'd have had to push it past a busy junction to park further on. However, the police let me off when I explained what had happened and produced the bill for the repair.

Jer