915 grinding.......
 

Hi all,

I am having gearbox trouble.

When trying to get the car in gear it grinds....badly. If I pull back towards 2nd I might get lucky, but for most part it still grinds. Seems as if it does not disengage completely.

So adjusted clutch, changed cable. No luck. The lever has plenty of travel.

Pulled the engine and tranny yesterday.

Sadly enough, clutch, release bearing and fork look fine. Plenty of gear lube.

Could it be that the po has placed the lever wrong on the rod not giving the fork enough room to push the bearing in enough to disengage the clutch?

What I noticed cleaning the tranny was that when in neutral the axles still spin when I turn the shaft. If I put resistance on the axles they dont. But neutral is not completely neutral if you get my drift.

Any suggestions on where I should look for faults would be highly appreciated. I dont want to put the engine back in before I am fairly sure that I have made a difference.

Christian.

pics

http://forums.pelicanparts.com/uploa...1396615456.jpg
http://forums.pelicanparts.com/uploa...1396615494.jpg
http://forums.pelicanparts.com/uploa...1396615532.jpg

You don't mention the coupler, hows that? Pull inspection cover off and take a look. What year? Check the fork at the TO, is it bent or ready to break off?

Residual friction will make the shafts turn in neutral, that is pretty normal.

Can you shift fine with the engine off? If so, it is not in the gear box.
How much travel are you getting at the end of the cable? Inspect the pedal cluster.
Look at the fork carefully, a crack is hard to find. Take it OFF the shaft to look at the back side.

Clutch looks good. PP looks good. Fork is on correctly, but need to inspect the back side.

Thanks a lot guys,

I Can shift it with the Engine off. I dont Think it is the coupler.

When in gear I cant start the car...it dies. So clutch probably not disengaging.

Could it be that the lever and fork are not put correctly on the rod, so that the for doesnt push the bearing far enough? I gået absolut 3cm of traver as is.

The box is a 915 923 for the 912E.

Also check your pedal cluster bushings and make sure that the clutch pedal roll pin is intact. A broken pin will let the pedal "spin" on the shaft.

Do not forget that one can adjust the clutch cable at the pedal as well, but the guys above are pointing you to the right direction, the cluster. Did this just start happening one day/minute, or was it gradual?

Well, that sure isn't a "915" clutch, so that leaves us discussing a 912E...

The roll pin for the connection between the clutch pedal arm and the clutch pedal shaft will certainly be suspect. You must remove it to verify that it's OK or breaking.

EDIT; Ooops, missed the clarification in post #5...

Actually it got worse latly. Sometimes I can shift after double clutching sometimes it will go in 1st after pulling for 2nd. Now it wont even take R. So strange.

Well I hate to see that the pin is the culprit since I never took that as an issue.

I will check tomorrow.

Thanks all.

Well rebuilding the pedal cluster is never a bad idea - time well spent even if this does not fix the issue.

That this happened gradually speaks to a slowly-deteriorating item. The pin can shear in the cluster over time (deform, then break).

The pin, when it fails, will usually do so a little at a time. Many times it will collapse slightly before breaking, which will allow the clutch to kinda work. Also, does your pedal board have a clutch pedal "stop?" If yes, its position can be just low enough to stop the pedal before the clutch disengages.

I will check the pin guys. The problem is that I can only check that when the engine is back in. I obviously did it wrong....

Have a nice weekend all, and thanks a million.

edit, but of the pin fails you lose onthe lever.....I have plenty on the lever ... 3 cm.

No, no, no! You can remove the pedal assembly from the car with the engine/trans out. Actually it's easier, pull the thing and take it apart on the bench! The pin can be the first step...

Thanks Pete,

I should have checked the pin before dropping the motor. Dont think that is the culprit since I have good travel at the lever....but will check.

Thanks guys!

Thinking about your issue, I remember seeing, maybe three times during my career, the weld partially fail at the short arm/clutch shaft joint. This would be the weld just below where the front of the clutch cable attaches. I never saw one fail completely, but the times that it became an issue, I saw it "flex" enough when subjected to the load of compressing the pressure plate, that it had just enough movement to prevent disengagement. Compared to the pin failing, I would classify this as highly unlikely, but worth mentioning.

Thank you Pete,

I will replace the rod when the engine is back in the car if I dont find anything else now.

Do you think that the lever is placed correctly on the rod? Here the lever is at is stop and touching the tranny casing pushing the fork to its max position. Enough to disengage the clutch? Hard to tell, I know.

Edit, Cant upload pics right now....

Also, could you take a look at page 110 - do you have a simpler way of telling if the lever is on correctly? I dont get it.

http://www.porsche912e.com/docs/912E_workshop_manual.pdf

What type 915. On 915the bearing should be on pressure plate

It is the 923 version of the 915.

Here are the pics of the fork at its max reach - when the lever hits the casing of the tranny.


http://forums.pelicanparts.com/uploa...1396707452.jpg


http://forums.pelicanparts.com/uploa...1396707566.jpg

Anyone for a shot at my question in#16.

Cheers,

Christian

Anyone....For explanation on how to align lever on rod like shown in the manual page 110 I will buy all the beer you can drink ........with nuts!