CLUTCH PEDAL VIBRATION

[Doggie Daddy]

i have a seriously annoying vibration coming from the clutch pedal. this is in a 2000 fl70 with the cummins 8.3 engine and 7 speed spicer tranny.it is most noticeable when i am in 7th gear at cruising speed. i am able to get it stop for awhile by jabbing at the pedal(deppressing it about an inch) but it doesnt take long before it is back to making a racket again. i have my own idea that it is being caused by the clutch needing an adjustment,but if someone else has an idea what it could be i would appreciate the info,thanks. DD

 

[copdsux]

Funny you should ask about this problem on the day AFTER I put my 2001, FL-70, 6 speed in the shop for a new clutch. After asking about a half a dozen mechanics, I started to believe there must really be a problem with the "throw-out bearings" The main symptom
was the incesant NOISE!! I couldn't turn the radio up loud enowgh to
drown it out! Sounds like you be having the same issue. By the way,
I was quoted prices from a low of $900, to a high of $1400. A Freightliner dealer was actually pretty reasonable on their quote:
$1010, parts and labor. Good luck on solving your problem.

 

[rollnthunder]

Check the bolts down by the pedal.My brother in law just had the same problem.He had a broken bolt on the bracket or some where around that are.Hope it helps

 

[streetsweeper]

Several items come to mind that can cause the slack and pedal noise; First the throwout bearing & cross shaft or shift fork. The ears, pads on the fork or whatever you want to call them do wear quite a bit over time. Adjustment helps for a while......

The clutch brake wears out (it is the little metal disc with friction surfaces that goes between the BACK of the throwout bearing and input shaft bearing housing on the tranny). Its function is to stop the input shaft rotation to allow you to get in first gear and indicated by the grinding noise you hear and feel shifting into gear before takeoff.

The attaching bolts, yokes, bellcranks, hiem joints, clutch cable (for those with a cable) stretches out. The old style linkage can be a real pain in any mechanics rear. Especially when another mechanic has adjusted it to compensate for the travel distance of the pedal.

Redoing or getting it neutralized properly (the linkage) is a time consuming affair by the way and should be done at every clutch replacement interval. That insures that you recieve maximum life from the clutch asy.

How many O/O's & drivers grease the throwout bearing, clutchfork bushings and linkage attachment points regularly? Little tip about the throwout bearing being greased. Many pump grease until they see it appear at the back or front of the bearing.

3 strokes of a manual lever gun is safe, anymore you run the risk of wetting your clutch assy with grease, then the cussing begins later down the road. 4 or 5 strokes for the cross shaft bushings too. Its ok there if you see a hint of grease at those.

I apologise for the length of the reply. Hope it helps everyone to understand.

(I'll go hunt my Spicer factory manuals & double check Ok?).

 

[Weave]

How old is your clutch? Did you try getting it adjusted yet to see if that stops the vibes? That problem does sound true to a worn throw-out bearing- basically the clutch assembly has some imbalance.
If adjusting it doesn't help, it's going to have to come out and be replaced.
-Weave-

 

[Weave]

With the 6 and 7 speed syncros, freightchaser, the rattle noise is actually considered normal when the clutch is properly adjusted. Hard to believe, and annoying, but true. You figured out the cure- turn the radio up The big-truck clutches do this a little bit too sometimes.

 

[copdsux]

Noise update!! The clutch is out and services are scheduled for noon
tomorrow. It was shot. Also, rear main seal was leaking and had to be replaced; seal where gear shift enters the tranny was leaking; and
another seal, of some sort, had to be replaced. The good news: The
labor costs are LESS than estimated and the difference will cover the
above mentioned repairs. Yes, Virginia, there is a Santa Claus and
some honest mechanics!:7 :7

 

[david11]

The clutch pedal vibration is an annoying and
common occurrance in the Business class Freightliner.
Most of the time you can gently lay your foot on the cluth
pedal and the noise will dissappear. I have fixed this problem by
raising the hood and attaching a bungee cord from the clutch pedal
arm to anywhere you can attach the other end. The worse the
clutch rattle, the more tension required on the bungee cord. This slight tension should stop the rattle or at least make it
tolerable.