Removing transmission....Fact not Fiction
From : marsh monster
Q: .. .. inline ========== ========== nospamsal1@qwest.net big al ok by what design the master cylinder is above the slave cylinder. gravity would put some pressure on the slave cylinder. i dont see any way for the slave to back off the throw out arm. on an old truck with mechanical linkage there are two springs to keep the throw out bearing off the pressure plate fingers. and when adjusted correctly it works. al ========= ========= the slave does not back off the throw out arm. it stays in contact with it. release arm why......because if it didnt ..... it would fall out the ball seat on the release arm and when you stomped down on the clutch pedal the rod would shoot out into the bellhousing.....and the slave cylinder piston would come blowing out. which would be a nasty thing and quite the inconvenience to repair all the time. a spring placed behind the apply piston inside the slave keeps the piston forward pushing forward the apply rod against the release arm moving the release bearing forward on the bearing retainer which rides in contact with the pressure plate......at all times unless the systems fubared. the spring tension of the pressure plate works against the spring tension of the slave cylinder apply piston......... thank you for trying to understand this crap design. so the engineers think its ok to have the throw out bearing spin continously. thats why they dont last as long as they used to. in the interest of lower cost the engineers have again screw us with a poor design. if the hydraulic system had a spring like budd said there would be no way to control free play. it would just return the slave all the way in. marshmonster has to go work on his truck....got to get that brake master cylinder below the level of the calipers another problem i had to deal with in my 74 camaro race car. at least i figured that one out by myself. al .
Replies:
From : budd cochran
not a hydraulics expert are you -- budd cochran warning!!! poster still believes that intelligence logic common sense courtesy and religious beliefs are still important in our society and might include them in his posts. .. .. inline ========= ========= mr-d150@spam.citlink.net budd cochran snip however an improperly bled hydraulic clutch can when the system gets warm from under the hood heat hold pressure on a throwout bearing . . .just like it would be if you rode the pedal. -- budd cochran ================= ================= thats not possible. the clutch will not apply under any scenario resulting from an improperly bled system. never... ever... marshmonster .
From : budd cochran
thats not possible. the clutch will not apply under any scenario resulting from an improperly bled system. try reading what budd said. he mentioned nothing about the clutch. simply said that an improperly bled system could result in faster than normal throwout bearing wear. that is not only possible its probable. i am not sure that this is exactly what budd either said or meant but if you actually believe this max prove it because in reality you are dead wrong. there is no way in hell that an improperly bled system could cause excessive wear to the bearing but it is highly probable to cause excessive wear to the clutch. i dont claim to be a hydraulics expert but there are some simple facts that seem to be completely distorted. no tom it depends on the volume of air left in the system. on hydraulic machinery in the muffler factory ive seen a 3 dia by 24 cylinder full of hot air bend a 3 exhaust pipe with a laminated wall 0.072 thick . . . .the heat coming from an oil based fire below the cylinder. yeah the set-up man lost his position because of poor housekeeping. then dont forget that all the power your engines make comes from coffee can sized volumes of air heated by burning fuel. first of all gas liquid and solids all expand to some degree when heated with the difference being that liquids and solids apply extreme pressure when any expansion occurs and gasses do not unless the expansion is significant. the reason why there is a slight gap required in a mechanical clutch linkage is due to the possible expansion of the mechanical parts partially engaging the clutch and causing excessive wear and slippage to the clutch not the bearing. the return spring serves to stop the linkage from rattling when in full release due to the required gap as much as anything else. and thats why there needs to be a gap on the hydraulic system as for gravity the weight of the fluid is so insignificant in a 3/16 line that i doubt that it could supply enough force to even move the clutch slave cylinder at all never mind move it with enough force to cause excessive wear on the bearing. air in the system will also not cause the slave cylinder to move because if it expands all it will do is push the fluid back into the master cylinder reservoir as at full release the ports between the master cylinder and the reservoir are open pretty much just like the brake master cylinder. it does however have the ability to cause excessive clutch wear because it could prevent the clutch slave cylinder from moving enough to fully disengage the clutch when required due to its compressibility. as for the bearing wear i would think that it goes through as much wear sitting at a single traffic light while holding the clutch in as it does with a year of wear with the light to non-existent pressure being placed on it during normal driving when the clutch is fully engaged. it sounds like the op simply has a bad bearing possibly contaminated with dirt during assembly causing excessive wear and premature failure. now that could be a possibility. -- budd cochran warning!!! poster still believes that intelligence logic common sense courtesy and religious beliefs are still important in our society and might include them in his posts. .
From : big al
when air is left in the system......... there is no way in hell it will ever warm up and expand causing the fingers to ride the bearing......especially being as the bearing is already riding on fingers. a question........... if the air could....expand due to heat and apply the bearing..... then why isnt the fluid expanding and applying the bearing air compresss brake fluid does not air expands when heated most fluids do not . . . or have you forgotten how a hot air balloon works generally taught by the time you get to the third grade. -- budd cochran liquid does expand when heated. this is high school physics. thats why hot water rises or classifies. youre confusing this with compressing liquids. we were taught you cant compress liquids and even that is false. under enough pressure it will compress. ever hear of hot ice no al i am not confusing compression with expansion and id appreciate it if youd quit talking down to me like im a kid. the hot air rises for the same reason as the water convection but hot air also expands. -- budd cochran warning!!! poster still believes that intelligence logic common sense courtesy and religious beliefs are still important in our society and might include them in his posts. .
From : Annonymous
.. .. ========= ========= al answers to yer questions...... 1 i have pulled a hundred or so mopop standards 4x4s. 2 the first one caused a couple skint knuckles....... the last one was a breeze....2 days ago 3 as already stated by others in the thread...... yes....seperate the t-case from the tranny. 2 you end up with a gag-awfull shudder because the flywheel looked good to you....so you you scrimped and didnt have it machined. very good description of all the work required marshy. i am just a bit curious about the need to have the flywheel resurfaced each time. my reason for this is that i used to have a 74 ford 3/4 ton with an np435 4 speed in it. the first time i had to change the clutch which was shortly after i bought it with 115k on it i found the flywheel had deep grooves in it from the previous owner wearing the clutch down to the rivets. i didnt bother having the flywheel resurfaced. young no money didnt care. i had no shudder from the clutch due to the worn flywheel surface. over the years i did experience a couple of occasions when the clutch would shudder but each time on disassembly i found it was because a couple of springs on the clutch plate itself had broken. i beat the hell out of that truck too. i would put a choker around a log in a log deck hook it to the ball on the hitch put the truck in granny and give er the gas. sometimes the back end of the truck would get jerked 3 feet to the side trying to get that log out. i have no doubt that this is what would damage the clutch plate. in each instance of shudder i found the clutch plate itself had a couple of broken springs but the plate itself had very little wear on it. i put another 135000 hard miles in 16 years on that truck before i bought my 03 dodge. and the last time i changed the clutch on it the grooves on the flywheel had smoothed out to just light waves on the surface and there was no shudder. have things changed so much that a new surface on the flywheel is critical to smooth operation of the clutch i can understand how a glazed surface would contribute to clutch slippage although that old flywheel had almost a mirror sheen and was still just fine. hd .
From : big al
.. .. inline =3d=3d=3d=3d=3d=3d=3d=3d=3d =3d=3d=3d=3d=3d=3d=3d=3d=3d mr-d150@spam.citlink.net budd=a0cochran snip however an improperly bled hydraulic clutch can when the system gets warm from under the hood heat hold pressure on a throwout bearing . . .just like it would be if you rode the pedal. -- budd cochran =3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d =3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d=3d thats not possible. the clutch will not apply under any scenario resulting from an improperly bled system. never... ever... marshmonster .
From : budd cochran
when air is left in the system......... there is no way in hell it will ever warm up and expand causing the fingers to ride the bearing......especially being as the bearing is already riding on fingers. a question........... if the air could....expand due to heat and apply the bearing..... then why isnt the fluid expanding and applying the bearing air compresss brake fluid does not air expands when heated most fluids do not . . . or have you forgotten how a hot air balloon works generally taught by the time you get to the third grade. -- budd cochran warning!!! poster still believes that intelligence logic common sense courtesy and religious beliefs are still important in our society and might include them in his posts. marshmonster sips his axle grease .