[alss]

OK new glitch..finally got the motor back in the car after having it dynoed..everything went together very nice. While cranking the motor to get some oil pressure I hear a banging/knocking sound from under the car..coincides with the motor turning..hits at the same spot on the 360 deg circle, and almost sounds like a interference hit..well it went away after cranking for about a minute so we fired the motor...no issues or noise but.....clutch feels like crap and is vibrating up and down. Clutch is loose on top and bottom and very hard in the middle and the vibrations seems to get worse when pressing the clutch in..so I tear it all back down, looking for some shiny spot or metal filings or something..but nothing!!..everything looks fine..all the parts are new and top shelf..hays flywheel, quick time bell, centerforce II dual friction clutch, new T 56 trans.

so far I have checked:

pressure plate bolts
flywheel bolts
bell alignment
clutch fork
pilot bushing (oilite)
starter

help..Im going out of my mind!!

thanks

Albert

 

[fridgeguy]

Have a look at the release bearing. I just bought a new release bearing when I was putting my car together. I don't know why, but I decided to check it out and the bearing was out of round, not centered. I'm thinking if I used it I would be dealing with the same thing you are. I wound up reusing my old one as there was nothing wrong with it.

 

[CDN SS]

Hmmm ......does it do it with clutch pushed in or just at idle in neutral

not something simple like the linkage missing the tensior spring ........ Sounds like the wrong TO bearing or clutch linkage adjustment ....what fork did you use ?

Check with CF they used to have a problem with the centrifigal weight system in clutch but that was long ago ....... and pbly not something that would show up at idle rpm


reread your post more carefully .......when you push in clutch it vibrates and gets worse with rpm??

......
Goota get it fixed ....... I want to see it run Thursday nite at CB..... I am thrashing to get my busted 12 bolt back together to makle sure I ready for CB

 

[alss]

Hmmm ......does it do it with clutch pushed in or just at idle in neutral

not something simple like the linkage missing the tensior spring ........ Sounds like the wrong TO bearing or clutch linkage adjustment ....what fork did you use ?

spring is in place..used the TO bearing from centerforce..stock GM fork(new)

Check with CF they used to have a problem with the centrifigal weight system in clutch but that was long ago ....... and pbly not something that would show up at idle rpm


Called centerforce..they were less than helpfull!

reread your post more carefully .......when you push in clutch it vibrates and gets worse with rpm??

does it at idle, with no pressure on the pedal..never tried it with any RPM..was afraid to..when I first got it installed..the first push of the pedal..it had a good amount of resistance then gave in..and not in a good way. The only thing I can think of is that the TO bearing fell off the fork while I was installing the trans..going to mock it up on Friday with a input shaft and no trans//just to see what is going on..thanks

......
Goota get it fixed ....... I want to see it run Thursday nite at CB..... I am thrashing to get my busted 12 bolt back together to makle sure I ready for CB

thats my intention!! ....and then I have to drive it..new rear for me too..4.56 gears to boot!!..cant wait to trash it!!

Albert

 

[CDN SS]

thats my intention!! ....and then I have to drive it..new rear for me too..4.56 gears to boot!!..cant wait to trash it!!

Albert

Great , 4.56 Damm I gonna have to gear down more ...

... yes CF not my favorite clutch company but alot use them with success ........gotta think this is a TO bearing / linkage adj related , long shot clutch is NFG
...... GM fork ....good ...... using all stock GM linkage assume ........when you get this issue sorted out and into fine tuning you will find if you try to get approx .050 air gap at disc you cant get good TO beaing adjustment gap .........you will pbly need to get an adjustable clutch rod .......pedal to bellcrank that will make adj the clutch ALOT easier .......or drill a lower hole in the bellcrank arm to move the stock clutch pdeal rod down about 3/4"

 

[CDN SS]

When you pull apart ....take a measurement from the fork ball to flywheel ( assume its adjustable) ......... is the fork at 90* to the block or slightly ahead but not alot

 

[alss]

When you pull apart ....take a measurement from the fork ball to flywheel ( assume its adjustable) ......... is the fork at 90* to the block or slightly ahead but not alot

Bill..no adjustable ball..do I need one??..how do I check that measurement?..is it to the back of the flywheel..or the front face?..never had to check that before but never went with a aftermarket bell..gonna mock it up with out the trans and see what it does..have a input shaft and a extra TO bearing collar.

I agree with you that I think its a TO bearing issue..I think It may have fallen off the fork when I was installing the trans..we'll see

everything looks good but something aint right!....any thing else I missed??..times running out from Nashville!!

thanks

 

[68chvlss396]

Albert, here is the procedure for adjusting the geometry of the clutch fork with an adjustable pivot ball. Just an FYI, I have a Lakewood blowshield with the Hayes flywheel on mine and had to adjust it.

http://www.chevelles.com/forums/attachment.php?attachmentid=40011&d=1300708687

 

[CDN SS]

Albert, here is the procedure for adjusting the geometry of the clutch fork with an adjustable pivot ball.

http://www.chevelles.com/forums/attachment.php?attachmentid=40011&d=1300708687

There you go !!

OK .....yes Albert this is the game when you go aftermarket .....On the net like this and not in your shop easy to be give advice hopefullyu I am not steering you bad but in reality pretty sure your issue is the linkage / TO bearing is just not working the pressure plate correctly, so yes in most cases you will need an adjustable ball ....... the above link is the basics ......and a good guide, the frustrating part is that every combination of parts , bellhousing , block plate , fork, pedal linkage clutch etcetc will be a little differrent ...... so use the measurement as a guide ........I use a McLeod adjustable TO bearing as well to get it all correct .......you may not need one so dont panic on that just a FYI

Hopefully someone smarter than me jumps in especially one you using a CF clutch with your brand of Bellhousing ......I use different stuff so not smart to give you the measurement I use

Do you have a hole in the bottom of you bellhousing that you can check flywheel to disc "air gap" with a feeler guage when clutch disengaged ..........if not when you have apart you may want to consider drilling one for later clutch tuning ......after you get this sorted out, again just a FYI

 

[CDN SS]

Albert ....you pbly know this but if not here is a link to show you the proper clutch linkage / fork geometry ......... see fig 2 ......... this will make it pretty clear why you may need an adj ball ........if you set up not like this now only way to get the fork geo is withthe adj ball .......then once thats done move to the linkage aadj to to your freeplay / TO bearing gap

http://www.hurst-drivelines.com/files/Clutch_Linkage_Installation_Tips.pdf

 

[blumont]

I have the quick time bell, gm fork and centerforce clutch with my tko. I had to use the adjustable stud for the fork. Adjusted .like shown on Figure 2 that Bill posted. Everything works fine.

 

[alss]

Thanks Bill..good stuff Checked all my measurements and all are good!

OK..problem's found and solved...got to check everything!!

1. crank was hitting the block!.Would make for a good clunking sound...ZL-1 blocks have a plate for the cam on the back of the block..its about 1/4 of a inch thick...the stroker crank has a counter weight, and it was hitting that plate..just needed to grind off some material ..no more banging!

2. clutch fork was hitting the side of the bell housing in the middle of the stroke..needed to cut a little of the side..plenty of room now...

going to put it all back together on Friday..thanks for your help

 

[CDN SS]

Thanks Bill..good stuff Checked all my measurements and all are good!

OK..problem's found and solved...got to check everything!!

1. crank was hitting the block!.Would make for a good clunking sound...ZL-1 blocks have a plate for the cam on the back of the block..its about 1/4 of a inch thick...the stroker crank has a counter weight, and it was hitting that plate..just needed to grind off some material ..no more banging!

2. clutch fork was hitting the side of the bell housing in the middle of the stroke..needed to cut a little of the side..plenty of room now...

going to put it all back together on Friday..thanks for your help

Great .....so much for internet experts guiding you :noway:

 

[66 BRONZE]

Thanks Bill..good stuff Checked all my measurements and all are good!

OK..problem's found and solved...got to check everything!!

1. crank was hitting the block!.Would make for a good clunking sound...ZL-1 blocks have a plate for the cam on the back of the block..its about 1/4 of a inch thick...the stroker crank has a counter weight, and it was hitting that plate..just needed to grind off some material ..no more banging!

2. clutch fork was hitting the side of the bell housing in the middle of the stroke..needed to cut a little of the side..plenty of room now...

going to put it all back together on Friday..thanks for your help

Glad you found the problem. I am curious though, you said your motor was just dynoed and all went well.The motor was installed and now the crank is hitting the block , the shop that dynoed your motor sould have heard that noise.Not trying to bust your balls, just a big red flag IMHO. Kinda makes you think.

 

[alss]

Glad you found the problem. I am curious though, you said your motor was just dynoed and all went well.The motor was installed and now the crank is hitting the block , the shop that dynoed your motor sould have heard that noise.Not trying to bust your balls, just a big red flag IMHO. Kinda makes you think.

I knew there was a problem when the motor was on the engine stand..I could see that it was making contact...and had ground a relief in the rear plate so the crank would clear...but not enough. When the clutch pedal is pressed it drives the crank forward a little...just enough to make contact with the rear cam plate and cause a stupid vibration in the motor. Since the dyno had no clutch the problem never surfaced until the clutch was depressed..release the clutch the noise went away..now its gone forever!!