clutch releasing but drivetrain still engaged?!?!

[411blackbird]

this is strange, got the old girl back together, engine, trans, diff cleaned up checked and put back in.

 

had the engine running for a while and just recently put the clutch slave cylinder and shifter on, bled the cylinder and adjusted the arm.

 

But, when it's running, even with the clutch to the floor i can't get it into gear, as if the clutch is still up.

i can put it in gear with the engine off. with the clutch in it will turn over, start and run.

as long as my foot is on the brake the car will stay still. releasing the clutch causes it to stall or it can be driven only in the gear i put it in to start with.

 

any ideas on what would cause this would be great thanks guys. and girls.

[datzenmike]

The clutch is still dragging against the flywheel and pressure plate. You are absolutely sure the system has no air in it? An incorrect release bearing collar on the clutch arm will cause this. Has the clutch assembly been replaced recently?

[411blackbird]

it's the original clutch with a release bearing from another 411 because i lost the original.

 

i've bled the system through countless times with the same result,

 

i did have a hell of a struggle getting the trans to bolt up to the engine, i'm going to guess this could be related.

 

are there any other possibilities that could cause the same problem bent input shaft...?

[datzenmike]

Was the clutch slave replaced or is this the original?

 

How much free travel is there on the clutch pedal before there is resistance?

[banzai510(hainz)]

was there a wrong T/ O Collar installed??????

[411blackbird]

the slave was replaced, but when it didn't work i put the old one back on with new internals and same problem, there is virtually no travel in the pedal before resistance and the push rod from the slave is almost extended to the point of no return.

 

the release bearing collar isn't the original but is out of an identical model, i havn't had the time to pull off the trans and check it all over yet but i'm guessing that's my only option left at the mo,

 

is there a possibility the splines on the input shaft/clutch plate have stuck causing the plate to be constantly pushed against the fly wheel?

[Cuts metal like mad]

could be the TO bearing or the pilot bearing... replace them both with NEW parts if you can.

 

Also make sure the clutch fork pivot ball is in good condition, try wiggling the clutch fork with everything installed, if it moves excessively you got a problem... but there are several causes, fork itself, the pivot ball, pivot ball spring, TO bearing... good luck

[datzenmike]

Is the clutch disc in backwards???? Can it even BE put in backwards???

[Cuts metal like mad]

if the clutch is installed backwards it would actually not fully engage, the flywheel side would not make contact. :)

[datzenmike]

But the PP side might be pressed against the plate.

[bonvo]

how long has the the clutch been sitting asembled ? the clutch disk could be stuck to the flywheel

[411blackbird]

found a way to make it work, for now, pulled it all apart went over everything to see any wear points, nothing that i could find, adjusted the pivot ball slightly. put it back together, same problem. but after hours of messing around i found that if the bell housing was spaced 5mm from the engine it worked perfectly, if this can help anyone figure out what else it could be please let me know!!!!!

[datzenmike]

Spacing the tranny back only alters the clutch arm, throw out bearing, and pivot ball distance from the clutch itself. Sounds like the throw out bearing collar is wrong size. Was it changed?? or the clutch?? or could it have been mixed up with a spare one laying around?

 

Does it have an adjustable slave push rod like the 521????

[CharlieBucket]

so i was wondering if you made in progress with this problem. i have the same thing. got my 74 620 fired up and running good finally and it wont go into gear. will go in gear with the truck off. thing about mine if you put it in gear and then try to crank it lurches foward, and that is with the clutch out. i noticed on both my datsuns you do not need to engage the clutch to crank the motor like on my nissans. my clutch also feels real soft like the pedal is doing nothing.

[MaxVP]

Hi,

 

Im having the same problem, is there a fix besides pulling the trany. With mine, before i got it the guy said that the clutch, clutch cover and the T/O was replaced. So if the T/O is the wrong one, where can one get a new one and where is there a list of part numbers for the parts??

 

thanks

 

 

Max

[datzenmike]

The throw out bearings are all the same, it's the housing that holds them that comes in different lengths. A short one would not reach far enough forward to totally disengage the clutch when the pedal is down... a longer one would not allow the clutch to fully engage when the pedal is up.

 

Haven't tried this, but if you were to make a slightly longer push rod for between the slave and the clutch arm, this would push the release bearing further forward into the pressure plate to release the clutch disc.

 

The only problem with this is that the clutch fork must move further back and may bottom out against the opening in the tranny case.

[banzai510(hainz)]

The throw out bearings are all the same

 

Not true ,L20 trucks and z cars have a wider shaped bearing for the 225mm flywheels

 

http://catalog.eautopartscatalog.com/archsoftware/importedcarpartspfp/wizard.jsp?partner=pacific&year=1971&make=NI&model=510--001&category=I&part=Clutch+Kit&partnerSession=2ed75d1f02987300780f2fe21f9ee4c3

 

on sale @Rockauto.com 57$ use the RSS logo up on top and ckick on it and it will lead ya to the sale iteam highlighted

http://www.rockauto.com/catalog/raframecatalog.php?groupname=Clutch&a=RSSW1209978&carcode=1209978

[MaxVP]

The throw out bearings are all the same, it's the housing that holds them that comes in different lengths. A short one would not reach far enough forward to totally disengage the clutch when the pedal is down... a longer one would not allow the clutch to fully engage when the pedal is up.

 

Haven't tried this, but if you were to make a slightly longer push rod for between the slave and the clutch arm, this would push the release bearing further forward into the pressure plate to release the clutch disc.

 

The only problem with this is that the clutch fork must move further back and may bottom out against the opening in the tranny case.

 

Well i have adjusted the rod that on the slave cylinder out as much as it can, so there is no play at all on the release arm, and it felt the same way as it was when there was teh recomended play as described in the haynes manual.

 

Max

[MaxVP]

Greetings again,

 

Just talked the guy im buying the 510's from, he told me that the mechanic told him that when he took out the trany to replace the clutch parts the old ones had like 4 or 5 big washers in behind the T/O and that he did not put them back in because he thought that the new clutch kit would fix the gap, so it seems some one use big washers as shims to make the clutch totally disengage. So thats is also, im assuming now, why it seems in need 1/2" more of travel to totally disengage the clutch. So here is a question, are there 510s that havwe a shorter T/O then the ones that is supposed to be in there?

 

 

Max