Help diagnosing clutch/trans problem

I've been loaning out my 2005 NB to a friend who is in town for about a month. A few days ago, she called because she was stranded in traffic. She said there was a loud bang, and then the car wouldn't shift out of gear, so she got into the middle turn lane and killed the engine.

When I got there with my truck, I was able to shift into neutral easily enough with the engine off, but I noticed that the clutch pedal was only about half way up. I thought maybe the brake fluid had gotten low, causing air to get into the clutch slave cylinder. This would have been an easy fix, but unfortunately, the brake fluid reservoir was full.

My friend (who is not very technical) said that a couple of days before that, she had an episode where no matter how she shifted, the car seemed to stay in a low gear, no matter where she shifted. She turned the engine off/back on, and then it was OK.

My friend initially said she knew how to drive a stick, but when I picked up the car, she said it must be her fault, because she stalls frequently, and she doesn't think she's very skilled with it. I don't know what to make of this; she could have just been rattled and blaming herself instinctively as some people do, or there could be some substance to it.

Please help if you have ideas on diagnosing the problem. Thanks!

Additional info: When the engine is off, I can shift into all the gears.

Could it be that a spring finger broke off the pressure plate?

When you're shifting with the engine off are you using or not using the clutch? Any difference between the two (with engine off)?

Throwout bearing or finger, kind of sounding like tha's the direction this is going to take. Not sure, however, if these would make big bang noises.

At any rate, I'd think that if you can shift through the gears, and it really does feel like you're getting positive changes, then it's not a broken shift fork.

I'm betting a spring let go and a piece jammed between the clutch and flywheel.

^^^ Oh, yeah. I think that that's the winner!

UhOh said:

When you're shifting with the engine off are you using or not using the clutch? Any difference between the two (with engine off)?

Click to expand...

There doesn't seem to be any difference shifting through gears (engine off) whether the clutch is in or not.

UhOh and Abacus -- thanks to both of you for your help.

Another theory: The clutch is (I think) the original Sachs, and the car has about 240K miles on it. The DMF has rattled like crazy since 161K when I bought the car. With my friend's inexperienced clutch use (abuse), the DMF might have finally broken.

Whether it was the DMF or a spring finger, I agree that something getting between the clutch and flywheel would explain all the symptoms. So I will plan to replace the clutch and have high confidence that the transmission itself is probably OK, and a new clutch will fix it.

Abacus wins the prize!

Actually, it turns out that the Sachs DMF clutch for TDI BEW is supposed to have a missing finger. Here's a photo:


However, the entire back side (toward the transmission) of the friction disk had zero friction material, and there were chunks of friction disk that fell out. There are scores on the pressure plate disk where the friction disk rivets are.

How many miles on that clutch?

I had pretty much the same thing happen when I bought my 05. I took it to get it aligned and the kid that worked for the garage just had to see what that little diesel torque was like, so I suspect he dumped the clutch and the two halves separated. Of course it was rattling before hand and a new clutch fixed me right up.

UhOh said:

How many miles on that clutch?

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I'm not sure. I bought the car at 161K and it now has about 235K on it. I don't know if the clutch was ever changed before. It is a Sachs DMF, so if it was replaced, they put the original factory clutch back in.

Tdijarhead said:

I had pretty much the same thing happen when I bought my 05. I took it to get it aligned and the kid that worked for the garage just had to see what that little diesel torque was like, so I suspect he dumped the clutch and the two halves separated. Of course it was rattling before hand and a new clutch fixed me right up.

Click to expand...

This clutch has had a hard life -- I taught several teenagers how to drive a standard in it. And I suspect that abuse was the trigger for this failure as well. The young lady I loaned the car to while hers was being fixed said that she knew how to drive a standard, but when it broke, she was sheepish and apologetic about her lack of skill. It's hard for anyone to admit a weakness sometimes, and especially at age 20, when you're trying to appear all grown up, but you aren't yet.

No matter. I'm installing a Luk, which is much smoother, quieter, and has a lighter touch. And it's my first clutch replacement, so I have an opportunity to learn, as well. However, if came at a really bad time -- we're in the middle of a house move, so I've pretty much had to set the clutch replacement aside for a week or two while we move.

Adding to the length of the project:

• I didn't know which stretch bolts to get for the project
• One of the CV joint boots was starting to split, and the other 3 are hardened as well. So I got rebuilt axles from O'Reilly.
• I ordered a long XZN socket for the Luk flywheel bolts, but it's the wrong size, so now I've ordered a whole Nieko set.
• The rear main seal is leaking; got a Victor Reinz replacement
• The oil pan gasket is leaking; got Permatex "The Right Stuff" Grey on order.
• The valve cover gasket is leaking, have a new one on order
• The whole engine is covered in oily dirt
• etc. etc.

And many of these issues require ordering parts from out of town and then waiting a week to get them.

Dan

shoebear said:

Actually, it turns out that the Sachs DMF clutch for TDI BEW is supposed to have a missing finger. Here's a photo:

Click to expand...

The Sachs and LuK versions have been supplied as pre-assembled units, including the flywheel bolts already in the FW. The disc has holes in it to access the bolts and the diaphragm spring has missing finger and notches in it to allow bolt access. This only works for the first bolt up, cause as soon as you release the clutch, disc its out of position.

Check the fork for wear also. How are the axle CV joint seals in the trans? Trans fluid change time?

Don't be alarmed if the new clutch pedal effort is less that the old one, as a disc gets thinner, the release effort increases.

And might want to personally check out the straight drive driving skills of anyone you let drive the car.

Good luck.

Thanks GCBUG00. How common is it for the axle seals to go bad? I thought about replacing them, but since they are not leaking and I don't need to disturb them, I thought I would leave them alone. However, I'm all for leveraging my labor and taking care of things while they are easy to do.

On the other hand, if an axle seal needs to be replaced later, only the affected axle would need to be removed, which is much easier than the trans.