help? clutch wont disengage

[66Dartdriver]

I just switched over from auto to 4 speed and I cant get the clutch to completely disengage enough to put it in gear. Its a 66 dart with an aluminum od bell housing. I talked to brewers they said it would work if I used a 66 clutch fork with a pivot they sold me. My pedal goes down about half way like it should and then seems to bind up. I have the clutch rod adjusted out to the point where it is firm against the pressure plate so there isnt any more adjusting room to go. If I push in the clutch all the way it will start in gear. I did have to fabricate the bracket for the zbar pivot on the bellhousing it it level and seems to be on the correct spot.

 

[toolmanmike]

Dang, Must be something with 66's LOL I share your pain, I had the same problem when I replaced my clutch last spring when I put my fresh motor in. I went from a 9 1/2" to a 10" clutch and nothing else changed. I replaced all the linkage and rebuilt the z bar. I also replaced the fork and pivot. I never did get it to work or adjust correctly. I ordered Brewers clutch kit, fork and pivot and had my local Clutchmasters check it out. It was set up perfectly and I hope when I install it (hopefully soon) I will be able to adjust it and it will work as designed. I wish I had an answer for you but I don't. Apparently the pressure plate is a different dimension than the stocker and the fingers are closer to the flywheel (just a guess) It appears like we need more stroke from the petal pivot because the adjusting rod doesn't help. If you adjust the petal for a couple inches of free play at the top it won't disengage when the petal is on the floor. If you adjust it so the clutch disengages 3/4 the way to the floor then the throw out bearing rides on the pressure plate fingers all the time and ruins the bearing. Keep in touch. We'll beat this thing yet! toolmanmike

 

[66Dartdriver]

you are exactly right its like there isnt enough stroke. I figure it is either the pressure plate or the placement of my zbar-bellhousing pivot but brewers said if it is level it should work. I thought about putting a washer in between the pressure plate and the flywheel bolts? at this point I am ready to try anything.

 

[Demon 408]

I have a 72 Demon so I can't relate directly to your issue but I wonder if it could be the clutch pedal to torque shaft (z-bar) rod? The 67-76 is 1.5" longer than the 63-66. Either way I'm confident Wayne at Brewer's can help you figure this out. Wayne helped me when I was trying to get my combination of parts right for my Quick Time Bell Housing.

What also helped me was having the trans out so I could eyeball the alignment of the throw out bearing to make sure it was centered over the pressure plate.

 

[67Dart273]

Some ramblings from the old guy

Take a good look at your linkage, preferably with a pal to help move the linkage so you can see what's up. On many of these conversions, you don't exactly have a factory situtation, so it's possible/ probable that part/ some/ all of the linkage "doesn't belong."

What you want to look for is that ever single lever point, that is, where a lever meets the pushrods, goes "over center" aproximately equally for the longest stroke.

I stole this from year one:

Notice that the lower lever on the z bar is "slightly forward" and that as you push down, it will go over center and "slightly back." You want each lever in the linkage--the pedal, the upper lever, the lower lever, all to do this same thing, otherwise as each lever starts to "lay down" you lose stroke.

(You may have one pushrod out of the wrong combo, might be too long/ too short)

Also do NOT discount the idea that your pressure plate may have a problem, or that you have a disk that is not compatible. The other day I saw a post where an aftermarket wheel was hitting the hub on a clutch disk. Get a buddy to operate the clutch, crawl under there and actually see how much clearance you are getting.

ANY chance you have the disk in front to rear?


http://www.yearone.com/yodnn/Techni...ams/MoparClutchLinkage/tabid/360/Default.aspx

 

[MtNemoMopar]

I have seen Z-bars mounted upside down. Bellcrank ratio is NOT 1 to 1, so maybe the stroke can change?

P.S. Love that blue on your car

 

[toolmanmike]

Some good suggestions here guys. Keep em comin'.

 

[toolmanmike]

Some ramblings from the old guy

Take a good look at your linkage, preferably with a pal to help move the linkage so you can see what's up. On many of these conversions, you don't exactly have a factory situtation, so it's possible/ probable that part/ some/ all of the linkage "doesn't belong."

What you want to look for is that ever single lever point, that is, where a lever meets the pushrods, goes "over center" aproximately equally for the longest stroke.

I stole this from year one:

Notice that the lower lever on the z bar is "slightly forward" and that as you push down, it will go over center and "slightly back." You want each lever in the linkage--the pedal, the upper lever, the lower lever, all to do this same thing, otherwise as each lever starts to "lay down" you lose stroke.

(You may have one pushrod out of the wrong combo, might be too long/ too short)

Also do NOT discount the idea that your pressure plate may have a problem, or that you have a disk that is not compatible. The other day I saw a post where an aftermarket wheel was hitting the hub on a clutch disk. Get a buddy to operate the clutch, crawl under there and actually see how much clearance you are getting.

ANY chance you have the disk in front to rear?


http://www.yearone.com/yodnn/Techni...ams/MoparClutchLinkage/tabid/360/Default.aspx

I have seen Z-bars mounted upside down. Bellcrank ratio is NOT 1 to 1, so maybe the stroke can change?

P.S. Love that blue on your car

I have been thinking the last couple hours about what you two guys wrote. When I put in my new clutch I didn't change anything but the plate disc and throw out bearing. I couldn't figure out how the geometry was messed up. (and iI was never too good at geometry) I had taken the z bar out to blast and paint and it looks like it could go in either way. I hope what you suggest solves our problems. I'll keep you posted and I'm sure 66Dartdriver will too. toolman

 

[Demon 408]

I have been thinking the last couple hours about what you two guys wrote. ...I couldn't figure out how the geometry was messed up. (and iI was never too good at geometry)...

Hey Mike...that's why your clutch is messed up, you are applying geometry to a problem that requires physics! :-D

The mechanical clutch is a series of levers and fulcrums. In physics a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force (effort) that can be applied to another object or resistance force (load), or multiply the distance and speed at which the opposite end of the rigid object travels.

All this and I've only had two beers...after a few more and I'll be a friggin Rocket Scientist!

 

[66Dartdriver]

well I know for sure I have the Zbar in correctly. As far as the parts I got the pedals, zbar, pedal to zbar rod, the adjusting rod, and the clutch fork from a 66 3 speed manual. I even tried the pedals, zbar and fork that came with the aluminum bellhousing out of a newer abody and it binds up at about th same spot thats why I figure it has to be the pressure plate or where I set up the pivot on the bell for the zbar. but I made a template from the 3 speed bell housing so it is damn close to where it needs to be. I mean within an 1/8 inch. When I spoke to Wayne at brewers he said that should be close enough to work. i am stymied?!

 

[67Dart273]

How bout some

of the linkage? This would give us some idea of where the leverage "is."

 

[Demon 408]

thats why I figure it has to be the pressure plate or where I set up the pivot on the bell for the zbar.

That may be where your problem is at. Did you check to see if throw out bearing was centered on pressure plate (without trans installed)? I had that problem with my Quick Time bellhousing, see my thread on my install:
http://www.forabodiesonly.com/mopar/showthread.php?t=60549;
go to post #5. If the clutch fork and pivot bracket are not correct it can force the throw out bearing out of alignment when you push the clutch.

 

[Demon 408]

How bout some

of the linkage? This would give us some idea of where the leverage "is."

If you fill them with beer it will increase the leverage...

 

[66Dartdriver]

I will get some pics as soon as I can and yes the throwout bearing is centered. Brewers has a template for drilling the newer aluminum bell and I used the clutch fork pivot that brewers sent me. It does seem to bind rather than just run out of stroke so you may have something there.

 

[daliant]

Is this a diaphram style pressure plate? I had the same problem with a power wagon once, the clutch would only partially disengage and seemed to bind up halfway down. One of the fingers broke off of the diaphram spring and jammed up the pressure plate. Just something to check while your under there.

 

[66Dartdriver]

I went out last night to take some pics of the zbar I noticed that my bracket got bent from me pushing in the clutch so hard. you can see in the top two pics. so I guess that tells me I have to go back to the drawing board to get a better placement for the bellhousing pivot It must just be out of alignment enough that it is binding up the throwout bearing on the input shaft. I am thinking if I was just running out of stroke there wouldnt be enough force to bend the bracket. I will keep you posted.

 

[MVRCorp]

Perfect!!!! The first picture shows the problem. With the pivot bent forward it shortens the throw of the rod preventing complete release of the clutch.
Remove the pivot on the engine, straighten the bracket, heat treat it, bolt it on and tell us how it works.

Jim

 

[1968FormulaS340]

Perfect!!!! The first picture shows the problem. With the pivot bent forward it shortens the throw of the rod preventing complete release of the clutch.
Remove the pivot on the engine, straighten the bracket, heat treat it, bolt it on and tell us how it works.

Jim

In addition to this…….

 

[Demon 408]

Dartdriver, I see a couple of items that indicate you may have the wrong parts. I reposted your picture with two arrows pointing to the problem areas. First, your bracket bent because your z-bar is too short and it put stress on the end of the ball pivot. Compare this area to the picture of my clutch setup. Second, it appears that your clutch fork is angled forward (toward front of car). Again, compare to mine which is almost 90 degrees to centerline of crankshaft. Have you checked to ensure your fork is 5/32 of clearance from the clutch disk when it's released? Hope this helps.

 

[caferacerx]

http://www.brewersperformance.com/proddetail.asp?prod=TS636

 

[66Dartdriver]

Thats great thanks for the input now I will make some changes and see how it works. Hopefully I wont have to pull any more of my hair out! Hey 1968formulas340 thanks for finding that clip for me lol !! I will keep you guys posted thanks again.

 

[66Dartdriver]

Ok after talking with wayne at brewers for the third time I found out I cannot use the zbar and clutch fork that I got from a 66 dart with a 3 speed manual. turns out the fork is 1/2 inch too short. So I ordered a new clutch fork, Zbar, and while I was at it I ordered the bellhousing pivot too cause at this point what the heck right? got all that monted up and guess what? same thing It is still binding about 3/4 of the way. Here are some pics of what is in it now. Dont mind the crafsman sockets I used for spacers, at this point I didnt want to start welding on to the new parts until I know if they are going to work. Take a look.

 

[67Dart273]

Did you ever get the pressure plate checked?

 

[66Dartdriver]

well I pulled it out and looked at it it seems ok it it is brand new but you never know. I have thought about ordering in another one and swap it out just to be sure. I didnt think this would be rocket science but it certainly is frustrating.

 

[Demon 408]

You're correct, it's not rocket science but it can be a pain. Try to get a "helper". You need to be under the car to watch the linkage and throw out bearing and pressure plate while you're helper pushes the clutch pedal. There is a finite number of parts that can be causing the binding that your experiencing. Remove the clutch rod and verify that the linage is operating smoothly and correctly. Move the clutch fork and throwout bearing back and forth to ensure it's not binding. Re-install the clutch rod, if binding occurs then the problem is either (1) flexing of the linkage under the stress or (2) the pessure plate is FUBAR or (3) you installed the clutch disc backwards. See below "Chevy" link describing what happens when you install the clutch backwards:

http://www.ls1tech.com/forums/manual-transmission/1148091-clutch-disc-backwards.html

Hopefully you didn't make a Chevy bonehead mistake. O