New transmission - clutch only depresses halfway

[drivenachodrive]

I've just installed a new transmission, clutch, pressure plate, pilot bearing, and starter in our Vanagon. I just got everything put together and pressed the clutch to try to change gears - it went straight to the floor with no resistance. Must be air in the line.

I bled all 4 brakes and then the clutch. Now the clutch has resistance, but it hits a hard stop halfway through its stroke.

Next bad thing: I can shift without pushing the clutch in (van is on jacks without wheels, so I'm testing it by air driving). As I cycle through the gears the wheels spin faster, so the transmission is doing its job. However, it seems the clutch is slipping when I accelerate. It's not fully engaged. When I stop the van I can smell slight clutch burning smell.

So what could be going on here? It seems the clutch is partially engaged at all times, but it won't fully engage or release.

My research shows that perhaps the throwout bearing fork could be broken, but it's brand spanking new. Is there any way I'm getting out of this without taking the transmission back out? By the way, the slave cylinder plunger is operational when pressing the clutch, so I don't think there's an issue with the slave.
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[?Waldo?]

There's a possibility that the clutch pedal freeplay is set wrong. Release pressure at the bleeder and before depressing the clutch pedal see if the clutch still slips.

[drivenachodrive]

So basically go back there and release the bleeder valve without doing anything else, then close the bleeder? This might cause something to reset itself? If this is truly the solution, I will need your address so I can send you a million dollars!
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[?Waldo?]

It may cause fluid to squirt from the bleeder and allow the slave cylinder to relax. If the clutch then grabs correctly, your issue is with the hydraulics. If not, I can't think of anything else to do aside from dropping the trans.

[crazyvwvanman]

There are some pretty poor quality new fork-crossshafts out there. The ones I have seen failed right away when a crappy weld broke where one of the fork tines was welded to the crossshaft. I don't see any way to avoid pulling the tranny and looking at things.

Mark

[Wildthings]

Grab the clutch pedal and pull it up. If that fixes it you need to figure out why it isn't returning fully on its own.

[crazyvwvanman]

How about a couple photos of the clutch slave and the lever, from the side and the top.

Mark

[gelPsy]

See facebook... probably release bearing blocked.

Greetings from Russia...

.martin, gearbox already back in )
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[Christopher Schimke]

While you didn't mention changing it, here is one other thing to look at: There are two different length push rods for the slave cylinder. I don't have any measurements for you, but if you use a long rod in a slave designed for a short rod, you end up with exactly the same situation that you describe.
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[drivenachodrive]

I just had someone hold the rear hub while it was in gear, and he was able to keep it from spinning with his hands. Thus, clutch isn't engaging. Also, he said it felt like the clutch was hitting once per revolution - i.e. something's crooked in there. Looks like I'll be taking the transmission back out today.

Grrr...

When putting it back in, how hard should it be to slide it up into the engine? I have the clutch alignment tool. Last time it was a bit of a challenge, but it went. Should it be really easy, or will it put up a fight?
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[MidwestDrifter]

It sounds stupid, but you did have the other hub secured right? Because of the differential you can hold one wheel and the other will spin.

The transmission should slip on fairly easily once you get it lined up. Do NOT use the engine to trans bolts to pull it together, you could cause some damage if you do that.

Unrelated (but common thing) make sure you have a starter bushing installed in the bell-housing.

Good Luck!
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[drivenachodrive]

With one wheel secured, it is impossible to hold the other one when it's in gear. Clutch seems to be engaged.

When the engine is running and it's in gear, I can watch the rear hub spinning. When I depress the clutch, it doesn't disengage, and the wheel continues to spin. Thus, the clutch won't disengage.

What damage can be done if the transmission is forced into place? Like I said, it didn't go easily. It seems to me that the pilot bearing could be damaged, but I can't imagine anything that would cause the symptoms I'm experiencing. Ideas?
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[crazyvwvanman]

Naturally that depends on what it was that was stopping it from going in easily. How hard was it forced in? You could damage the pilot bearing or maybe the shaft fork(s), or release bearing.

Was the slave cyl mounted before you mated the engine and tranny? If so then the fork could have been extended with the release bearing pushed out too far. Better to mate the engine and tranny, then before fully raising the tranny mount the clutch slave while there is more room to deal with the tricky bolts.

Mark

[presslab]

Forcing the two together is bad mojo. With the clutch disc aligned, I slide the trans into place until the splines touch. Then I put it in gear and turn the output flanges until the splines are engaged, and then slide it home by hand. A little wiggle may be needed but nothing more.

A smooshed pilot bearing will cause major clutch drag. Can't say what caused your funky pedal problem.
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[MidwestDrifter]

Just brainstorming here, Is it possible to install the clutch disk backwards in the WBX clutch? That could limit the clutch travel by causing the pressure plate to hit the clutch plate?
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[drivenachodrive]

My clutch disk had a nice little notation on one side that said "flywheel side". Pretty sure I got that one right After bleeding the slave again to no avail, I've decided to remove the transmission and see what's going on in there. Let's just hope that I don't need any more parts, because all I have now is one extra pilot bearing and that's it!
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[Vango Conversions]

It can be a pain to align the splines of the input shaft with the clutch. The transmission will slide in a certain amount and then usually stop. At this point don't force it, but apply some pressure while either spinning the axle flanges back and forth or have someone put a breaker bar on the engine crank pulley and turn it back and forth while you jiggle the transmission. Either way you do this the transmission should be in gear. Eventually, the transmission will slide into place with very little resistance.

When you have the transmission out, make sure the release fork and bearing move freely and don't bind. also make sure the splines of the input shaft and clutch disk are smooth.

You may want to remove the clutch disk and make sure it slides onto the input shaft smoothly. It's possible that they sent the wrong part. Put a light smear of anti seize or high temp grease on the input shaft splines and where the bearing rides on the sleeve. Your clutch kit should have come with a little packet of the right stuff.

The main thing is not to force anything, you can do major damage that way.

Good luck

[drivenachodrive]

All right, transmission is pout. Everything looks good in the bell housing, except that I noticed something strange with the pressure plate.

When the pressure plate was bolted down, the spring fingers were all compressed (pushed toward the flywheel). As I loosened the 6 bolts holding the pressure plate to the flywheel, I could easily see the fingers relaxing and moving away from the flywheel.

When these springs are pushed in by the thrust bearing, this disengages the clutch from the flywheel. I assume this had something to do with my problem, although I seemed to have the opposite issue: the clutch was always engaged and I was unable to disengage it from the flywheel by pressing the pedal.

Anyway, what could have caused those fingers to be compressed in a static condition? Could it be that I had bolted it in an incorrect orientation? I had it lined up with the 3 press-pins on the flywheel, so I assume all was correct. Perhaps clutch disk was off-center? I swear I used the alignment tool, but it's possible I made a mistake.

Ideas?
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[Wildthings]

The fingers should have clearance to the clutch cover of about 3/16" with new parts, IIRC. Someone please correct me here if my guess at the measurement is off. The clearance allows for the normal wear the clutch will experience over time. When the clearance goes to zero the clutch is shot and failure is imminent.

If your clutch disc is too thick or your flywheel is machined wrong the clearance could be too much which would cause your symptoms. Somewhere in the manual should be specs for both of the above.

[drivenachodrive]

I'll have a look at the Bentley, but bear in mind that I've installed a brand new Bosch pressure plate and clutch. Just popped them out of the box - should be within spec.
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