New Clutch issue driving me crazy!

El Pinchi

Well-known member
I can't figure out this clutch problem and its bugging the crap out of me. I've been trying to trouble shoot the problem with no success. LOF told me that I need to give the clutch more time to break in. I've roughly clocked about 1500 miles on the new set up. I don't think its the clutch.
So here is what has been done before it all started.
I recently installed a new Ashcroft R380, a new LOF HD clutch with HD throw out bearing, new 4.6 L with tophat, new cast iron slave cylinder, new SDO cast MC. I should point out that at when cold, it is difficult to shift into 1 and 2 gear sometimes. 2nd is the more problematic.

The 110 was running fine for about 2 weeks then I a weird humming vibration started whenever I depressed the clutch. I feel it on the pedal and on the stick shift. I hear the vibration noise below the tunnel. Its pretty random but its becoming more frequent. When the engine is cold, it tends to happen when still parked and pressing the clutch pedal and shifting into any gear (not moving). When I'm driving, it can feel it when I press the clutch and shift. If I hold the clutch pedal down while moving and leaving it in gear (riding the clutch) I feel the humming vibration on the stick shift, pedal, and tunnel areal. I just bled the MC/slave to make sure there is no air in the lines plus the fluid was dirty even though its all new. If feels like the clutch is not fully engaging when I press the pedal and shift int a gear. I do have to point out the the tech that did the work did not resurface the flywheel. He said it didn't need it. I never saw it out and just trusted his experience.
Could it be the flywheel with hot spots?
bad throw out bearing?
Are the push rods for LT77 different lengths than the R380? Maybe need to change this?
Please let me know your thoughts of what it could be and what I should check?
Thanks in advance!
Eddie
 
Last edited:

Napalm00

Technical Excellence Contributor
Can't tell you exactly what the issue is but here's my two cents.

I would never install a new friction disc without resurfacing.
There is different length lt77/r380 pushrods
Check all exterior driveline points: u-joints , handbrake, ect
 

El Pinchi

Well-known member
Can't tell you exactly what the issue is but here's my two cents.

I would never install a new friction disc without resurfacing.
There is different length lt77/r380 pushrods
Check all exterior driveline points: u-joints , handbrake, ect
I totally agree with you about the resurfacing. I asked him to do it but I think he forgot and said it looked fine. I will have to drop the tranny and resurface the friction plate. Checked the driveline looks good.
Ill have to look into the correct length push rod and get that ordered.
Thanks Matthew!
 
Last edited:

Parrie

Well-known member
If everything was fine for a couple weeks I'd be surprised if it were a push rod. I'd lean more towards a chunky flywheel or throw-out bearing.
 

acheck

Well-known member
the throwout bearing is more surely not made by LOF. it is probably not a terrible manufacturer, but the symptoms you are describing could almost *only* be throwout bearing related as its the only part which is put into rotational service (and could thus make noise) when you depress the clutch pedal.
 

RDavisinVA

Technical Excellence Contributor
Sounds like the clutch master cylinder is out of adjustment.
How much free play do you have on the petal?
There is no need to resurface the flywheel if it is flat and not worn.
 

Z.G

Well-known member
the throwout bearing is more surely not made by LOF. it is probably not a terrible manufacturer, but the symptoms you are describing could almost *only* be throwout bearing related as its the only part which is put into rotational service (and could thus make noise) when you depress the clutch pedal.
It's all LOF, they produce the kits
 

Parrie

Well-known member
Not to hijack the thread...I see a lot of folks go w/ LOF clutches, is there a particular reason why? I just purchased the Ashcroft HD Valeo kit...is LOF considered superior or just personal preference?
 

Napalm00

Technical Excellence Contributor
Not to hijack the thread...I see a lot of folks go w/ LOF clutches, is there a particular reason why? I just purchased the Ashcroft HD Valeo kit...is LOF considered superior or just personal preference?

They offer much more clamping force / durability with similar engagement effort
 

RDavisinVA

Technical Excellence Contributor
robert, how could a clutch master cylinder cause a noise and vibration?
If the pressure plate is being compressed too far, it will cause the springs to shutter and the result inside the cab is a vibrating petal and noise.
After a while, it will damage the clutch springs to where they release and engage unevenly and create vibrations that cannot be fixed without replacing the clutch pressure plate.
If the driven plate springs are weakened by uneven release they will shorten and rattle.
 

jymmiejamz

Founding Member
Callsign: KN4JHI
From when I was going to do a Tdi swap on my D90 I seem to remember there are two slave cylinders and two different rods available for the R380. Any chance you have the wrong slave? I wouldn't think that would cause the humming/vibration, but just a thought.
 

LRover

Member
If the tech didn't resurface the flywheel, chances are he may not have changed the pilot bushing either. I had a worn bushing cause a weird vibration similar to what you describe.
 
Top