|
|
|
#1
|
|||
|
|||
clutch - manual mechanical
Recently I replaced new the disk, pressure plate, and release bearing. Adjusted to specs with 25 mm pedal freeplay. Drove perfectly for five miles. Then, without noise or warning after five miles, pedal dropped to clutch freeplay of 75 mm. Limped home. Readjusted clutch to 25 mm freeplay which involved four turns of adjustment screw. Let car sit several days. Then when I went to start the car, freeplay was gone and clutch tight. Freeplay simply disappeared in interim. Again adjusted freeplay to 25 mm. Adjusting screw returned to where it was at first adjustment.
Verified parts are correct and release bearing facing correct direction. Also, verified mechanical external linkage not bent and in correct working order. Clearly something inside bell housing. I have not driven the car yet pending additional thought about what caused problem in first place. Any suggestions?
__________________
Douglas 1959 M-B 220S cabriolet |
#2
|
||||
|
||||
Air in hydraulic lines?? .......this would explain the problem solving itself while sitting undriven for several days. Yet master and slave cylinder old rubber seals can seep fluid causing symptoms you've described.
|
#3
|
|||
|
|||
As I indicated in the original subject line, my clutch is mechanical, not hydraulic. No master or slave cylinder associated with the clutch in the pontons.
Thanks for the response anyway.
__________________
Douglas 1959 M-B 220S cabriolet |
#4
|
|||
|
|||
Doug -
I am sure that you have thought of this. It seems to me that the only pieces capable of creating and taking away slack in the linkage are the pressure plate and throwout bearing. I can visualize how it is happening - the pressure plate/diaphragm/throwout bearing is not returning fully, hence play at the pedal. But over time, it does return, and take up the play. I cannot come up with a satifactory reason as to why this would occur beyond some sort of binding as the throwout bearing moves on the input shaft or a defect in the diaphragm.
__________________
Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe |
#5
|
|||
|
|||
As I recall the last time I replaced a Ponton clutch, many years ago, the new pressure plate (coil spring type) came with a wire clip installed under each of the 3 release arms. These clips were to aid in installation but then needed to be removed. One other possibility, which may be a long shot - a loose motor mount or trans mount.
Happy Motoring, Mark
__________________
DrDKW |
#6
|
|||
|
|||
Thanks for the two responses. First, I did put grease inside the release bearing sleeve/shaft/body. There is a small indentation on the inside of the sleeve for this purpose. It slid well before installation of the transmission.
Second, I did remove the staple-shaped clips before installation. I discovered them quite by accident when one fell out. Further thoughts?
__________________
Douglas 1959 M-B 220S cabriolet |
#7
|
||||
|
||||
Bent or cracked throwout arm??
|
#8
|
|||
|
|||
I verified that the throwout arm/fork is intact--not cracked or bent--and is riding on the ball as it is supposed to.
Another thought is that somehow the clutch disk got binded on the splines of the transmission input shaft, either because of a burr or because something expanded and jammed after heating up following use. I note that I did not put even a small daub of grease on the splines, so I have to consider either of these a plausible explanation. Any other thoughts? Anyway, before starting the engine and driving the car again I pumped the clutch 100 times. No problem. I drove it twice for some time around the neighborhood with much shifting. So far, so good. I am cautious so I am not yet ready to declare victory. This particular ponton model does not have a transmission mount. The motor mounts appear in decent condition and anyway this clutch adjustment problem was not present before the new clutch job.
__________________
Douglas 1959 M-B 220S cabriolet |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|