What are the symptoms of a won clutch guide tube?

[Lof8]

*worn clutch guide tube

I've been tracking my s50 e30 for about 5 years (with G260 trans). The first 4 were with a Sachs m20 clutch. Eventually I started getting some slippage and figured the clutch had enough. I ordered a Spec stage 2 to put in. With the trans out, the Sachs clutch didn't look awful. The guide tube had some slight scoring, but nothing too concerning, so I put it back in.

Now, after two track days with the Spec clutch, I'm experiencing the same slippage. I'm thinking the guide tube may be the culprit, but I don't have enough experience to be sure. I'm not looking forward to pulling the trans again and certainly dont want to do it a third time if I don't get it right on this try.

Please give me your thoughts. thanks

[Lof8]

When I search "guide tube" in the title, I get 2 results. It doesn't seem like this is a common issue. This sucks - pulling the trans is wack.

[jalopi]

the hell is a guide tube? i'm assuming you're talking about the quill? i don't see why the quill or "guide tube" would cause the clutch to slip - all it does is hold the throw out bearing in place while it rotates and/or moves forward and back. even IF the quill was scoured super bad and the TOB had issues with returning, the force of the pressure plate fingers would force it back (doubtful though, the quill would have to be SUPER fucked up for this to be the case)

my guess is you've got a clutch adjustment issue or something. maybe the clutch wasn't broken in properly? who knows. but i'd stop thinking about the quill, it's most likely something else

[Wh33lhop]

I'd suggest a close inspection of your clutch hydraulics. Something isn't letting the clutch fully engage.

[pandaboo911]

My "guide tube" was beat to hell and hasn't given me any problems. I didn't grease it either. Your slippage is coming from elsewhere. You should baby it the first 500 miles to break it in.

[Hooffenstein HD]

What's the slipping like? Just as you let off clutch, only when you put all the power down, or just general clutch slip all the time?

[Lof8]

What's the slipping like? Just as you let off clutch, only when you put all the power down, or just general clutch slip all the time?

The slippage happens late in the session, when temps are high. It happens in 3rd and 4th gear, with the gas pedal to the floor. release clutch, apply throttle, and rpms rise faster than the car accelerates.

I did break it in for close to 1000 miles before bringing it on track. I also replaced the rubber clutch line with a new ss one at the time of the recent clutch change.

So it seems the guide tube/quill experience is that being in flawless condition is not a necessity. Maybe the Spec clutch just isn't up to the task. But the Sachs one I took out wasn't in horrible shape. I'm not sure what direction to look.

[jalopi]

The slippage happens late in the session, when temps are high

sounds like that's your issue - poop clutch disc. if it was a hydraulic/adjustment/other mechanical issue i think it'd be showing up even when cold

i'd personally get another sachs since you said it worked for you for almost five years. the disc itself may have looked just fine but maybe the disc was starting to glaze over? maybe that's why it's slipping? regardless, the sachs was reliable for years and the spec has proven itself to be junk.

also make sure to have the flywheel ground again this time too, never know if the excess slipping made for a poor surface again

[Wh33lhop]

The Sachs clutch disk may not look too worn, but keep in mind you have another 90hp or so going through it (torque matters more but you get the idea). So, it's likely fine behind an m20, but it will fall short behind an s50. Hydraulic issues could be exacerbating the issue, or spec clutches could just be garbage--I don't know much about aftermarket clutches.

[z31maniac]

I still don't know what a "clutch guide tube" is?

Input shaft for the transmission?
Clutch fork?

[FredK]

23111224845

[ajhostetter]

23111224845

No no, it's 8675309

[nrubenstein]

Run an E36 M3 clutch/flywheel assembly.

[TobyB]

To answer the original question, a binding/worn/sticky guide tube gives you a stiff pedal that doesn't have much 'kick' back to retract. It feels exactly like what it is- extra friction
in the clutch system.
Fords do it. I've only had one E21 do it, and that was water getting down in there
through the timing light hole.
If your clutch travel feels good, I'd doubt it's a tube problem.

(the tube is the sleeve that the clutch throwout bearing rides on. Aircooled VW's didn't have them originally)

t

[Artful Dodger]

I would check the relationship of the clutch disc, pressure plate and flywheel. Maybe your flywheel is a bit worn down and you are not getting full contact pressure from the pressure plate.