Clutch problems


Capt. Mike

Moderator
Transferred to consolidate same topic.

Reiner Junior Member posted July 01, 2004 10:37 PM

I brought our 87 Westy to the garage for state inspection. Front breaks had to be redone (rotors, pads, bleeding). When my wife picked up the car from the garage she realized loss in power, clutch slipping and eroding rapidly. After about 10 miles the car didn't move anymore and she had to get towed back to the garage. They diagnosed a bad slipping clutch. Before the brake repair work the clutch functioned without any problem.
Today the garage finished replacing the complete clutch kit. The old clutch was worn out and easily broken in small pieces (heat). On the test drive the garage experienced the following problem: no power, slipping clutch, smell of burning clutch. The spare parts were the original F&S kit. Now they want also to replace the flywheel. Does that help? Sounds for me rather a problem of the hydraulic system. But where does this come from? Does working on the brake circuit affect the clutch hydraulic circuit (air, different pressure point)? After the brake repair the clutch had no distinct pressure point anymore. Can anybody help? Would like to drive from DC to the west coast in the coming days. But looks rather that I have start working on this myself (as the garage seems somewhat lost).
 

Capt. Mike

Moderator
Clutches do not start wearing suddenly nor catastrophically in 10 miles without someone doing something wrong.

Presuming you are correct in that the clutch worked perfectly when entering the shop, there is nothing in the brake job itself that should affect the clutch. However, the brake master cylinder reservoir is the clutch master cylinder supply. Thus any bleeding requires bleeding of the clutch as well. Why did they bleed? The replacement of pads and rotors does not require bleeding -- just possible removal of some excess fluid from the reservoir as the rotor piston are pushed back.

"Hydraulic clutch system" has its own topic. Bled improperly, I suppose it's possible the clutch would be slipping but the usual symptom is the other way -- the clutch doesn't disengage fully and gears clash.

The only other thing that would lead to quick slipping failure is a complete blowing of the rear crank seal, but that should be evident by gobs of oil coming out of the bell housing and show on the dipstick. Small seeps rarely affect the clutch and then slowly.

It sounds like your shop has messed up the clutch hydraulics. A complete description and repair is given in the Bentley.

The flywheel rarely causes clutch failure, especially in that time frame. And it usually gives other symptoms such as grabbing, shuddering and vibration. One engaged, even a rough flywheel does not slip. They only hasten wear during the brief intentional slip of starting out and changing gears.
 

Forster

New member
Thanks for this advise. I checked with the garage this morning. They actually had done a proper bleeding of the clutch before I came.The problem which did further irritate the mechanic was that "in gear 1 the clutch did not work properly". All other gears worked fine. When testing myself I immediately discovered that this was not the first gear, but 80% of 100 you ended in gear 3, and for gear 1 you had to go halfway to reverse gear. Obviously, the car had "no power" starting in gear 3 and the clutch smelled badly. With a bid of aligning and adjusting of the gear shift, all the gears can now be shifted nearly normal. Only gear one and two need a bid of special care, which the car had already for the last 3 years. Seems like the gearshifter and the stick bushens need to be changed. Thanks again
Reiner
 

vw-traveller

New member
Clutch pedal down
79 westy manual


hi capt mike,
sorry about the posting in the transmission group.
So so reinterate, I was driving the bus, suddenly the clutch pedal fell down, felt just like when the engine is out. I suspected the cable broke, negative. I hotshifted home. So today i took out the engine to inspect it, everything seems to be fine. I can move the lever on the tranny and the clutch release bearing moves in and out. I put it back togther yet same problem.
Any idea?
 

Capt. Mike

Moderator
Some assumptions I'm making: The engine to transmission mainshaft connection is complete because you can drive in a particular gear and can even change gears with a 'double clutch' action; After removing the engine, you observed the clutch operating shaft (item 5, diagram 5-15.4, fig 15-11) correctly move by moving the clutch lever, (5-15.5, fig. 15-14); You have pulled the clutch cable out of the housing and it is intact; driven & pressure plate inspected and OK.

Right so far?

That would leave me to belive that the problem is a sheared shaft between the clutch pedal and the clutch pedal lever assembly, (5-15.5, fig 15-16). You'll notice how the shaft goes through a housing that would hide parts of it from view. That would mean moving the pedal is not moving the clutch cable at the pedal end and the pedal should basically fall to the floor since it no longer has the return spring help of the clutch lever.

One other place to check is the flexible guide tube mount for the transmission end of the cable, (5-15.5, fig 15-17, mount "A"). If the end is no longer attached, either because of coming unclamped or broken tranny mount, the cable can move and use up the specified "sag" instead of moving the lever the necessary amount to clear the clutch. I wouldn't think enough to let the pedal flop to the floor, but . . ..

5-15.6 table g. lists some other areas to check under "3. Clutch Dragging". Most of those wouldn't give the floppy pedal symptom, though.
 

vw-traveller

New member
Hi Capt. Mike,
WOW you are knowledgable!!!
Just as you supected, the flexible guide tube mount for the transmission end of the cable, (5-15.5, fig 15-17, mount "A") fell off! And even worse, the hole for the upper screw is partially broken out. What do you propose I should do?
I am hoping there is still enough left to put another screw in, but how long will that last?
And also when I remount this, should I take out the clutch cable?
if you're interested; pics of problem: http://tfrommel.com/clutch/clutch.html
 

vw-traveller

New member
Okay I got some local opinions and decided to put the stud in and then JB welded around it. I hope that'll hold
thank for all your help
 

SteveS

New member
I think Captain Mike already addressed this problem but I want to make sure because the dealer wants to blow it off. I had the dealer put a clutch and VW remanufactured engine in my 1985 camper last November. As soon as I started driving it, I noticed an occasional shudder from the rear when starting in first. I could not make it shudder; it just did it randomly. I did notice that it was more frequent when in stop-and-go traffic, carrying a heavy load, or going uphill. Or it could just happen on level ground. I brought it in once and they said it was the throttle body, which they rebuilt since they could not find a new one. That didn’t help at all (it didn’t even help the idle much). I waited a few months for it to get better or worse, but it didn’t, so I brought it in again today. They checked it out (as far as they could without removing the transmission) and decided that I am not giving it enough gas when I start. I told them I’ve been driving this vehicle for 20 years and never had this problem until the engine was replaced. They said it must be I’m not used to the new engine; I said if that’s the case why didn’t it happen when I bought the camper new? You get the idea. They finally agreed to get one of the old-timers to look at it. Can there be any reasonable cause for this problem other than the clutch?
 

Capt. Mike

Moderator
I'm going to presume you are not experiencing engine lugging.

To determine if it is clutch/flywheel, you should be able to reduce the shudder with higher revs and much more slip, i.e. letting the clutch out more slowly and holding it at the position when it starts to catch. The shudder is usually the clutch attempting to grab, for example at high spots and this will minimize it. This is NOT a driving technique but for diagnostics only. One doesn't want to fry the clutch to compensate for a mechanical deficiency!

Start with the easiest step first, bleed the clutch again. Although it is not necessary to disconnect the clutch hydraulics for an engine change, it's always possible air got in. Air in the hydraulic clutch means it has irregular motion as the air compresses and decompresses.

A VW reman does not come with new flywheel, so the one from your old engine is still in service. Did you see it before the clutch job. Was it grooved, uneven texture, old heat or oil burn spots? I'll also ask did they replace all the clutch items, or just the disk? What about the pressure plate?

If you are doing a full reman, I would hope you did a complete clutch, including pressue plate, throw-out bearing, pilot bearing in the flywheel and tranny seal. I'm not a big fan of machining the flywheel unless absolutely necessary. Many shops do that as a routine and it does more harm than good. The clutch material is capable of bedding in rather quickly to minor circumferial variations and grooves if they are uniform around the flywheel.

As to the other side of your question, what else can make it shudder while engaging the clutch, usually just engine mounts. If it was an engine related, it should do it other than during clutch engagement, especially under load and lower rpms such as a hill.

Since this was done at a VW dealer, demand an appointment with the district service rep (while the engine & clutch are under parts & shop warranty.) It very much sounds like they are trying to blow you off.
 

SteveS

New member
Thanks, Capt Mike. They finally looked at the pressure plate and said it was "cracked." They replaced both clutch and pressure plate at no charge (they said it's an 8 hour job at $93/hour!). After looking at the pressure plate, the district rep agreed to pay for that but the dealership had to eat the labor and rental car. They were not happy, but they did do me right and I have to give them credit for that.
 

Capt. Mike

Moderator
A couple of comments: If the district rep authorized the clutch parts but not labor, it means he thinks the damage was caused by the shop during installation. VW is liable for the parts anyway, but they can kick back labor if it's a shop failure. They apparently think the pressure plate damage was shop error. Otherwise VW pays for labor, too.

If the shop is taking 8 hours for a clutch, I'd wonder what they charge for other jobs. It's moot to you now, but a clutch should be about 4 hours. It is not necessary to remove the engine again. Disconnect 2 CV's, shift rod, starter & 5 other bolts to get the tranny out. ½ hours tops to change the clutch once it's out. They must be charging individual rates for every step as if it was the only thing they did -- a job padding technique. Even R&R the engine & tranny shouldn't be that much. Think about it for future work -- ask to see the VW flat-rate manual.
 

Ludwig van

New member
I'm replacing the clutch in our 78 because for the last few seasons, it's been shuddering when warmed up, and with a trip to the Canadian Rockies coming up, I didn't want to take any chances on it.
Two questions.
First, I didn't find much oil in the housing, but the flywheel surface is marked with concentric black streaks that don't wash with brake parts cleaner. My inclination is to have the flywheel resurfaced to clean this stuff off, and to avoid putting the whole thing back together and finding that the problem was a warped flywheel. Is this a good plan? I don't know how I'd be able to tell if the flywheel was warped, or if the black marks can be safely removed any other way.
Next question - how does the release bearing attach to the lever? Bentley and Haynes are very vague on this, and their illustrations are pretty generic. They hint that the spring clip goes on first, followed by the retaining clip, but this looks like a pretty tricky job. I've been able to get the clips and springs off and on at the workbench, but I'm not eager to try it under the van. Any advice? (Unfortunately, I pried the old one off with a screwdriver and the springs flew off, so I didn't get much of an idea how the parts fit together)
 

Capt. Mike

Moderator
You can check for warp with a runout gauge. Doing it over a variety of diameters of the flywheel will tell you not only warp, but possible taper wear of the flywheel (inner more than outter, or vice-versa.)

Resurfacing a flywheel often removes so much metal, it's just as cost effective to replace it. You can clean one up pretty well with emery paper if it's just glazed with oil or grease. Blue streaks, however, often indicate overheating and that can effect the temper of the flywheel, which means it will have soft & hard rings, not condusive to good clutch grip & will accelerate groving wear.

The secret of getting spring clips on is to hold your mouth right and have your tongue hanging out ala Michael Jordan. But I do like to use a locking grip like the smallest needle-nose Vise-girps or hospital forceps. Look at the Bentley diagram Section 15-4, Fig 15-11 late-type to see how the spring clips and retainers face.
 

ajheesakkers

New member
Unable to shift into gear while engine is running

1985 Westy, manual tranny. About 3 months ago, I noticed a metallic vibrating sound while initially letting out the clutch in 1st gear. It only happened during the take off in 1st gear. A few km's latter I noticed that shifting into reverse or 1st was becoming harder, and often with a clunk. I am able to shift into all gears when the engine is off, but only grinding when the engine is running. When the engine is running and the clutch is down, the engine is pulling as if the clutch is not quite down far enough. I attempted to get her up on ramps, but did not have enough power. I noticed a strong "burnt" smell and the clutch pedal was soft. Since then I have checked the linkage, bled the clutch, found no leaks, all fluids are topped up with no success. I also have an 1987 Vanagon that I am attempting to get on the road for my wife and two (soon to be three) kids, and I am really hoping to get this problem fixed ASAP before spring- the road is calling. Thanks, Al.
 

Capt. Mike

Moderator
You didn't give mileage, but these are classic symptoms of a blown clutch. Clutches can fail in several ways. We think of the friction disk face wearing down to the rivets (screeching noise) as primary, but they can also get overheated from slippage (often comes with the worn clutch) and the disk friction surface glaze or disintegrate. I've actually seen a housing filled with fibres from a disintegrating clutch disk. You can look into the drain hole at the bottom of the bell housing to see if there are signs of debris at the bottom but that only confirms, not rules out.

You can also get failure of the pressure plate springs. Even one breaking would cause the clutch to engage unevenly and quickly damage it. Assuming you have checked the hydraulic side to be sure the slave cylinder rod is moving its full range, then I suspect nothing short of pulling the tranny to inspect the clutch will find it. This gives the opportunity to inspect seals, throw-out bearings, linkage, etc., as well.
 
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Mike Robinson

New member
Clutch / transmission noise

82 Westy diesel
Rebuilt tranny
Clutch 2 years old

Hope someone can shed some light on this!

Intermitant problem. It can happen in all changes, but usually between 2nd and 3rd - going up and down.

The noise lasts about a second and happens when the clutch pedal is lifted. It is a similar noise as clearing your throat!

No noise when stationary
No noise in neutral - clutch in and out
Only when the pedal is lifted in gear
No vehicle performance changes
No shuddering

Just a noise when changing. If I get the noise I can sometimes depress the clutch and lift again and it is gone.

Mike
 

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