THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Dear all,
few days ago while driving my 712 suddenly the clutch pedal turned hard to push and faced impossibilty to change gears. On the contrary, with engine off, it was possible to select all the gears. I dismantled gearbox and found out that clutch friction disc was worn and distorted with a broken rivet. So I changed the disk, greased a bit the shaft and rod articulations and assembled everything with the convinction that all was fixed. Pedal stroke was lighter and shorter than before. As I started engine it was impossible to insert any gear from neutral while if started in first with the clutch pedal pressed, the car tended to move slightly ahead; releasing the pedal it was possible to move and then to shift to second and third (didn't try higher gears) but was almost impossible to shift gears down. My sensation was that something was not allowing the rod to travel enough to make the clutch disengage properly; I tryied to adjust register nuts on the master cylinder but no improvement, just longer or shorter pedal travel.
What can I do?
is it a problem with hydraulic assembly?
or with clutch assembly?
or with gearbox syncrorings or gears or other parts?
Are clutch assembly all exactly the same or are there different executions with non-compatible parts?
I've got to solve it by myself (hopefully with yor help) as no specialist is available in my area.
Thanks for your suggestions and excuse me if terms are not the right ones.
Gunipinzmutt

Gunipinzmuut,
Did you replace the pressure plate, throwout out bearing, and the disc or just the disc? Did you resurface the flywheel? If you only repaced the disc and either the flywheel or presure plate is torn up it will drag like you are describing. It is always best to replace all of the clutch as a unit and resurface the flywheel for best results when doing a clutch job. That way all friction surfaces are absolutly flat and it will wear even.

Here's a few tips.
Many of these tips have been posted by Jim and me on this very problem.

The difficulty with the original clutch was probably due to partial disintegration as you have intimated. When you installed the clutch plate the thickness of that plate has obviously caused the diaphragm fingers on the pressure plate to deflect inwards towards the flywheel. A thicker plate causes more deflection a thinner one cases less.
The factory makes several different length pushrods available to account for this "tolerance" when changing plates. These we have on hand during clutch changes. There are by the way some variations on overall plate thickness and its sounds to me that you have an early pressure plate with a later driven plate (the one you installed).

As a rule, immediatly upon "stabbing the box" we tighten the mount 10mm nuts, insert the pushrod, and then operate the clutch. Once pumped up we SELECT a gear and with an assistant have he or she depress the clutch whilst you try to rotate the the prop drive flange by hand. If the clutch clears freely you have good clutch clearance and it will be easy to rotate all the gearbox innards, if not, then you must investigate why. Wayne has mentioned some of the obvious.
Best of luck
Dennis

A binding pilot bearing can give many of the same symptoms
Mark

I changed only the disk, not pressure plate or bearing or pushrod because all seemed in good conditions. Neither I resurfaced the flywheel. The new clutch plate was obviously thicker than the old one.
I realise now, from your tips, that there are different pushrods: are they specific for pinz or common with other makes? Is their lenght the only way to set the position of the disk?
Also different pressure plate thickness is a discovery for me! Unfortunatly I did not compare with attention the old and new parts when I decided to change only the clutch plate even if I had also replacements for pressure plate and bearing.
By the way, do you exlude any damage in the gearbox?
Thanks and ciao
gunipinzmutt

Gunipinzpmut
The different pushrods are Pinzgauer specific.
If you remove the pushrod from the release assembly (insitu) and measure it we can determine which rod you probably require. Simply push the mechanism back against the residual hydraulic pressure and you can fish it out.

The clutch plate can be inserted "backwards but the springs on the cush hub in the centre will foul the flywheel bolts. In most vehicle applications the off set is to the rear besides the flywheel face usually has "Flywheel side" stamped/ printed on the hub arrangement.

There is another situation which I have reported upon on "Buggered up gearboxes" in this forum. Should the oil level be run low, there is a tendency for the input shaft and top gear to seize together. It that situation a partial seizure of the gearbox will cause the transmission system to be permanently locked in top gear. Attempts to select another gear will often stall the engine or the interlock shifting mechanism will block attempts to shift to any other gear. It depends upon how the sezure has taken place.
.
In any case the drive flange must be able to be rotated easily by hand when the clutch is depressed. You can verify this at any time by selecting neutral in the transfer case and selecting any gear in the gearbox. With an assistant holding the clutch down it should spin freely.
hope that helps
Dennis

Dennis,
I changed the pushrod with another abt 4 mm longer I found among my second hand spares: now everything works perfectly!
Thankyou all for your precise troubleshooting tips!
Ciao
gunipinzmutt

Well that's a good piece of news, well done & glad you found the part to do the job.
Molto bene
Chio
Dennis
ps where in Italy are you, just curious again!