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Healeygals post on this subject got me worried. Just replaced the trannie/overdrive oil with Redline 75W-90. Took it out for a drive and everything was fine. An hour later went for another spin. Reversed out of the driveway, went to drop it into 2nd (to slide it up into first) but struggled to "find" second gear. Bypassed it, went straight to first. Then again, stuggled to find second. Then struggled to find third. Fourth was a bit easier to engage. Same thing happened when I downshifted. Everything was perfectly smooth an hour ago! Any thoughts? Thanks.
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More clutch linkage woes?
- Thread starter Brakin80
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[ QUOTE ]
Healeygals post on this subject got me worried. -- Everything was perfectly smooth an hour ago! Any thoughts? Thanks.
[/ QUOTE ]
Yeah - What car are you talking about? If it is a Healey BN1 or BN2, check the pedal free play. It shouldn't be more than one inch. If it is, adjust or repair as needed. The other post covers some of the details. The flimsy linkage can bend at anytime & change the clutch release point. It may have been marginal to start with.
The other end of the equation is that there MUST be enough freeplay to prevent the carbon faced throwout bearing from being in contact with the pressure plate under non operated conditions. Wear in the linkage pivots & attachment points can reduce this adjustment range to the point where you just cannot meet both requirements. All joints & pivots must be reduced to a minimum of slop. Of course the pull back spring must be operating to give full pedal travel. A frequent shot of grease on the pedal pivot tube fitting is also helpful.
If you are talking about a hydraulic operated clutch the same principles apply. Air in the system, low fluid level, balloning flex hoses, or worn linkage will cause the same problems. Additionally leaking internal seals in the master or slave cylinders will reduce travel. Sometimes the throwout fork is loose on the pivot shaft but you have to remove the transmission to fix it.
It would help if folks identified the car type in their posts.
D
Healeygals post on this subject got me worried. -- Everything was perfectly smooth an hour ago! Any thoughts? Thanks.
[/ QUOTE ]
Yeah - What car are you talking about? If it is a Healey BN1 or BN2, check the pedal free play. It shouldn't be more than one inch. If it is, adjust or repair as needed. The other post covers some of the details. The flimsy linkage can bend at anytime & change the clutch release point. It may have been marginal to start with.
The other end of the equation is that there MUST be enough freeplay to prevent the carbon faced throwout bearing from being in contact with the pressure plate under non operated conditions. Wear in the linkage pivots & attachment points can reduce this adjustment range to the point where you just cannot meet both requirements. All joints & pivots must be reduced to a minimum of slop. Of course the pull back spring must be operating to give full pedal travel. A frequent shot of grease on the pedal pivot tube fitting is also helpful.
If you are talking about a hydraulic operated clutch the same principles apply. Air in the system, low fluid level, balloning flex hoses, or worn linkage will cause the same problems. Additionally leaking internal seals in the master or slave cylinders will reduce travel. Sometimes the throwout fork is loose on the pivot shaft but you have to remove the transmission to fix it.
It would help if folks identified the car type in their posts.
D
bob hughes
Luke Skywalker
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Shooting from the hip on this one as I do not have my reference book with me, but I thought that the oil should be the same as for the engine, something like 20-50, going upto 75-90 sounds hypoid ish to me that goes in the differential or the steeriong box.
Bob
/ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif
Bob
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[ QUOTE ]
Shooting from the hip on this one
Bob /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif
[/ QUOTE ]
Bob,
This is one case where shooting from the hip doesn't work. A lot of people get fooled by the two different rating temperatures of gear oil & engine oil. Gear oil viscosity is usually rated at 100 degrees F. Motor oil viscosity is rated at 212 degrees F. Thus the viscosity of SAE 75W-90 gear oil is roughly equivalent to SAE 10W-50 engine oil.
A lot of people are having very good results with Redline MTL which is rated 75W-80 & Redline MT-90 which is rated 75W-90. These oils are rated GL-4 which means they don't have the sulfur compounds that destroy bronze synchronizers as do the GL-5 rated oils with sulfur which is needed for the higher contact pressures in hypoid axles.
These Redline oils are compounded to have a higher friction coefficient which enhances the synchro ring "grabbing" & usually results in quicker & easier shifting. A "good" motor oil is actually too slick for the synchros to work at optimum. As are "slick" additives. The Laycock overdrive clutches also benefit from a less slick oil.
BTW - ATF oils are usually rated around 5W-20 on the engine scale. Not too far off from the SU carb recommended 20 wt.
D
Shooting from the hip on this one
Bob /ubbthreads/images/graemlins/cheers.gif /ubbthreads/images/graemlins/england.gif
[/ QUOTE ]
Bob,
This is one case where shooting from the hip doesn't work. A lot of people get fooled by the two different rating temperatures of gear oil & engine oil. Gear oil viscosity is usually rated at 100 degrees F. Motor oil viscosity is rated at 212 degrees F. Thus the viscosity of SAE 75W-90 gear oil is roughly equivalent to SAE 10W-50 engine oil.
A lot of people are having very good results with Redline MTL which is rated 75W-80 & Redline MT-90 which is rated 75W-90. These oils are rated GL-4 which means they don't have the sulfur compounds that destroy bronze synchronizers as do the GL-5 rated oils with sulfur which is needed for the higher contact pressures in hypoid axles.
These Redline oils are compounded to have a higher friction coefficient which enhances the synchro ring "grabbing" & usually results in quicker & easier shifting. A "good" motor oil is actually too slick for the synchros to work at optimum. As are "slick" additives. The Laycock overdrive clutches also benefit from a less slick oil.
BTW - ATF oils are usually rated around 5W-20 on the engine scale. Not too far off from the SU carb recommended 20 wt.
D
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Yes - The last paragraph about hydraulic clutches & the parts about linkage wear & adjustment still apply. Your car just has less linkage.
D
D