Clutch studders!...Help me SOC brothers!

Noticed this the last couple of days.

Starting from a stand still I rev the motor to around 2k then slowly let out the clutch and the whole car shakes violently until I get moving about 5-10 MPH.

From a slight rolling start no prob.

If I rev her up to 3500-4000k then drop the clutch I get a little tire chirp but no studder.

Please help, I may lose all my fillings if this keeps up.

Jerome

Jerome,

I have seen several things that cause "chatter"
-broken Bowden bracket, taking the bend out of the Bowden tube
-broken/bent throw out fork
-loose pressure plate
-warped clutch disc
-oil on clutch disc (rear main seal)
-clutch cable begining to break ("spongy" cable)
-broken tranny mounts

I'll edit if I think of any others...
Do a good physical inspection. Look for oil leaks where the bell meets the block, look at the Bowden, look at your cable, etc...

Carey

BTW Does it "chatter" it in reverse?

I'll look tonight, thanks,

Jerome

Mounts...OK

Slight amount of oil along the case split, at the bottom of the oil pump and a liitle at the bell housing.

What the hell is the Bowden?

Jerome

Bowdem tube , usually black..a tube mounted to the side of the trans with a bracket and houses the clutch cable, should have a 1" dip in the Bowden tube and not straight. This can be achieved by adding washers at the male end next to the bracket.

Go through Carey's check list starting with the easy item(s)

Oil on the bottom of the bell housing... rear seal leak ?
May indicate oil on the clutch disc

Jerome,

I'm sure there is a more technical explanation, but here it is in a nutshell.
The Bowden tube. It's the flexible tube (spiral steel w/ plastic sleve) that the clutch cable runs through, from the rear of the chassis to a mount on the tranny just in front of the clutch lever. It's about a foot long. It holds a bend in the clutch cable.
The engine and tranny "flex" (twist) on their mounts when torque is applied. The Bowden tube "twists" with the engine, keeping the tension on the clutch cable even. Without it the clutch cable would be a straight shot to the clutch lever and when the engine/tranny "twist", the clutch cable would change lengths slightly and disengage the clutch When this happens, the engine/tranny "un-twist" the clutch would re-engage. The process starts over, and over... chatter.


When you have time, clean off the oil and see if you can't catch where it's coming from. Is there much oil on the garage floor?
(The oil at the bellhouse worries me a little, but could easily have run/blown there from elsewhere...)

Carey

I'll look again this Saturday.

Thanks!

Jerome

Damn, Alan. You type to fast. ;) Gordon :)


Now, I was typing one fingered, with the baby in one arm (her favorite toy is the keyboard!), but 15 min... !


Carey

Well the bowden tube is fine. I have a feeling I'll be pulling the motor this week.

Unless you guys think of something else.

Jerome

Did the clutch originally come from the "Mel Tillis, Stuttering Clutch Works? No?? well, I guess you're right and an engine pull is inn order.

See if you can borrow someone's motorcycle jack - makes it easy shmeasy.....Then you'll be in the "Big Leagues" of engine pullers with GB, Bill Drayer and me!!

gn

I wonder whatever happened with GB's engine disaster? Does anyone know what ever became of the car and the engine?

The Bowden tube. Text is in finnish, but I ques the pic tells it all.

Jerome, My Bruthaa, Checking the picture above, check to see if the clutch release shaft arm is straight up and down as shown. If it's cocked forward a little bit, something is amiss here.
If you do pull the engine, it would pay to pull the throwout bearing shaft(easy) and check it carefully. The area of the arm where the t/o bearing clips ride is thin on OEM shafts. The tip starts to bend forward, plinggg, the clip flies, and the bearing cocks crooked and you're SOL. If you have clips that are "U" shaped, replace them with the newer ones with the spring coil on them.

BD

PS. This info applies if you have the old style t/o bearing set-up. '61-'70 I believe.Newer models are similar but still are held on with spring clips.

Well I pulled the engine this afternoon.

Everything appears to be where it should. I haven't taken the pressure plate off yet but the outside of the clutch looks clean as a whistle. The inside of the bell housing looks clean also.

I may go out tonight and take the pressure plate off.

Is it possible that its a warped disk after only 2200 miles?

Jerome

Bill D. my clips are the spring style.

Jerome,

Also eyeball the trans mounts again and be sure they they are tight, I put a dab of lock tite on them.

After looking at the Bowden tube again it has about 1/2" of bend. Refer to Janne's picture. If that is the root cause why wouldn't the studdering show up sooner?

I'm still gonna look at the pressure plate.

Jerome

This is really starting to bug me.

I took the pressure plate off and the clutch looks like brand new. Like it should, it was new 2000 miles ago. No oil, no unusual wear. In fact you could still see the ink stanped on the clutch surface.

I really don't want to put the motor back in and still have the studder.

Arrrrgggg!

Jerome

Maybe the clutch is glazed or somthing. Someone else had this sort of trouble a while ago but I can't remember the particulars.

BD

What does glaze look like. The fly wheel and the pressure plate are shiny and clean. The clutch disk looks brand new.

Maybe I'll borrow the digital camera and snap some pics tomorrow.

I'm pissed, I'm gonna go play Half-life 2 and kill some Combine soldiers & zombies.

Jerome

Just a thought.... is your clutch arm (I don't recall the VW nomenclature) bent/cracked?

I'll go look...hang on.

Nope, looks good.

I always thought SOC needed live chat for situations like this.

Jerome

Jerome,

While your there, a 1/2" isn't enough bend in the Bowden tube allow 3/4" to 1". Your problem is within Careys list. I'm still leaning toward a lose or broken mount.

"What does glaze look like. The fly wheel and the pressure plate are shiny and clean. The clutch disk looks brand new."

Glaze is usually seen only on the clutch disk as shiny patches whereas the rest of the disk is matt finished. I've seen occasional pressure plates chatter if they were tightened in a funny order and simply warped because of uneven torque of the mounting bolts, but I don't believe that is your problem. Just make sure, when you re-assemble, that the pressure plate is centered in the flywheel depression and the bolts are tightened in a star-pattern in three successive rounds of increasing torque (6lbs., 12lbs., 18lbs)

Far more common on VW's, however, is that the Bowden tube isn't properly shimmed and is slightly out of adjustment. Many people simply put them together without checking for proper "sag" and never shim them, and so they chatter. It looks like a simple device, but is pretty complex in how it works and applies friction to the cable.

The proper amount of "bend" is 1 inch to 1-13/16". That's a LOT more than the 1/2" mentioned. These tubes often cause more chatter when it gets warmer outside (like lately). You'll need to remove the adjusting wingnut at the throw-out lever, and add washers between the collar of the Bowden tube end snout and the upper mount (on the side of the tranny). You'll find the tube snout is long just for this purpose. Add enough washers to get a bend of about 1-3/8" to be in the middle of the spec. Once you've got the proper bend, grease the cable before re-inserting it into the tube, reconnect the cable and re-set your pedal play for 3/4" - 1" before feeling resistance (I tend to set it at 1/2" - 3/4", but that's personal preference and makes the pedal feel a little higher).

Sorry for all you've gone through, but I think it's been the Bowden tube adjustment all along......

gn

Jerome, here's a link to a good site on T-1 Clutch problems. I'm no expert, but went through some clutch issues with my 1st Speedster R.

www.geocities.com/vwresource/clutch.html

I can't think of anything else other than the Bowden tube issue since your clutch was working properly before this, especially if the clutch and flywheel are dry. My suggestion about the Clutch release fork was just a shot in the dark as I had that problem with my VS....

Hang in there, you will find the problem.

Jim

I know, too little too late . . . and you probably don't care anyway . . . but I'd go with the Boden tube as well.

A couple of years ago a Buddy's car started to shake so badly leaving a dead stop that we had to pull the male end of the tube out of the housing/bracket and use a small fuel line clamp order to get enough dip in the tube to eliminate the studder/shudder. That's almost a half inch spacing at the male end.

This to say that, once you get it together and try adjusting the tube, you may find that a washer or two isn't enough spacer to get rid of the problem, but don't get discouraged. It took WAY more than a washer or two for us, but the problem was resolved.

I know, I know . . . we SHOULD have replaced the tube with a longer one . . . but we're just a bunch of chimps. Tools rather than stones, sticks, and bones . . . but still chimps none the less.

Luck,

TC

At the risk of sounding like a doofus, if it's glazed it might just go away on its own. Shortly after I moved to NC from TN I had a similar experience with a BMW I used to won. After a couple of months in heavier traffic than I was used to and in the heat of the summer it developed a serious enough chatter that I was contemplating getting a new clutch at 50K miles. Instead, I just lived with it for a few months and it went away. It was fine for the next 80K miles until I sold the car. I know it's unpleasant, but it might be a passing phase - sorta like puberty.

Now back to our regularly scheduled and more helpfull postings.

Jerome
If your bowden cable had the 'proper' bow and now the clutch chatters and the bow is less than recommended...something changed. It is possible the welds holding the tube the clutch cable goes through in the tunnel have broken. Remove the inspection plate where the shifter connects to the trans. The clutch cable housing will be toward the drivers side of the hole near the top. On mine (CMC) the cable protrudes through the floor pan in the area and exits the rear to the bowden cable. Check this tube for any movement as this will indicate a probable broken weld, there are three, allowing the bowden cable to loose the bend and never ending clutch chatter.
HTH Bill

Glazing does not genneraly go away. The problem is that the areas that are not glazed wear faster than the glazed area, producing an uneven friction surface, producing worse chatter. Every once in a while you can get lucky, but I wouldn't risk breaking something in the drivetrain when it's pretty simple to pull the engine in a speedster.

I think the Bowden tube always had 1/2" of sag in it. That's why I'm confused why is it showing up now. Maybe Gordon is right, it hasn't been this warm around here for about 2 years.

With the engine out I've really got a good look at the tranny mounts. They look fine.

Oh well, I needed the practice pulling the motor anyway. It will give me a chance to clean up the motor and the engine compartment.

Thanks for everyones help, I let you know what happens after my test drive.

Jerome

"MAYBE Gordon is right?!?!?!?!?"

Harrruuumpfffff!!

Just as a comparison to TC's friend using a 1/2" spacer, I went out and, in considerable heat out in the garage, measured the "sag" across mine, and it's about 1-1/4" (although it LOOKS like it's a lot more from below) and I have three (3) spacers between the collar at the end of the tube and the tranny bracket, or about 3/8" worth of spacers. That's pretty normal, too.

Most people, when they pull the tranny or install a new one for the first time, either lose the spacer washers or don't know they're needed in the first place, so they seldom get installed and THEN they wonder why the clutch is chattering.

BTW: VW parts counters used to offer three lengths of those tubes, in increments of about 5 or 6mm, if I remember right, to compensate for differing thicknesses of the front tranny mount (which sets the position of the tranny-to-frame length and the length of tube needed).

OK, so maybe I'm right, huh? Well, I'm gonna help you some more, too - you don't need to remove the wing-nut adjuster to add spacers to the tube end. Just loosen it til the stud is even with the back end of the adjuster, then loosen the tube mounting bracket on the tranny and remove it with the tube/cable still in it. Buy three or four, 1/2" ID lock washers (stainless, if you've got money), and use a Dremel to open up and even out the gap between the ends to a little more than 1/8". Take a pair of pliers and bend one side so that it becomes a flat washer (the ends should be even) with a slot on one side.
Now go back to the tranny, slide the bracket back out of the way, slip a washer over the cable and onto the tube snout. Replace the bracket and TIGHTEN IT DOWN (important), then measure the tube sag. If it's not at least an inch, repeat the last process adding one or more washers til it sags about 1-1/4 inch, then replace the tube end boot, re-set your pedal play (which would have become too tight anyway) to 3/4" - 1" play at the pedal and you're done.

Why do it this way instead of just pulling the adjuster off and letting the cable become loose?? Well, if you inadvertantly push on the cable, just a little bit, the eyelet at the other end may flip off of the hook at the end of the clutch pedal shaft and you'll then have to pull THAT and fix it as well. My way keeps tension on the cable so it can't flip off the other end.

gn

(Harrruuumpfffff!!)

Oh come on Gordon, don't be so sensitive.

Don't let some young whipper-snapper hurt your pride. If your not careful someday you'll be known as the ornery old coot on SOC.

Just to make you feel better I will follow your instructions to the letter :)

Jerome

and a Good thing, too!

Shoot! I'm not always right.....just seen some of this stuff lots more than once.

Hey, BTW; Just in case I'm not right, it wouldn't hurt to buff off the face of the clutch disk with 80 - 100 grit sand paper. Just dress it off lightly (both sides) so that the entire surface has the same matt look. Use a sanding block and light pressure. Do the same to the pressure plate and flywheel contact surfaces, but use 100 - 120 grit, just to break the shine, before you put everything back together........and don't forget to torque the plate back on in steps.

Thought about air conditioning for the garage yet??

gn

Jerome,

When you pulled the pressure plate, did all of the bolts seem to have the same torque on them?

Also, it is my understanding that the clutch cable tube that runs through the center tunnel has some welded brackets and if they break the entire tube will move forward, thus taking some of the sag out of your Bowden tube. This would explain a change in the bend all of a sudden...

Some of the more experienced VW guys can clarify this, as our clutch tube is a little different from the beetle.

Carey

Nevermind. I guess I should read better, Bill covered that one already...

BTW I can see the new GN signature already "The ornery old coot from Rhode Island" LOL

Alright, back to work...

Carey

You guys need to join the Last Comic Standing gang ...way funny !

Wow Gordon on the East and Vince on the West...... Stereo Coots

Yeah, but my knees are better looking than his........

Gordon
The OOCFRI

Says You!!

BD