Power assisted clutch

[zagazowFJ]

when i purchased my FJc... the "rapes-man" mentioned that the vehicle is equiped with a 'power assisted clutch.' i never took it into consideration except for the fact that the FJc downshifts very smoothly without having to rev-match the manual transmission system on my 6 speed.

my question is, this 'power assisted' clutch system. is it the reason why the manual 4wd option still doesn't get better mileage than the automatic option? i've noticed that if i'm at a rolling speed and pop the shifter in neutral, the revs dont automatically drop down to idle level...they stay at about 1200 rpm?!?! could this contribute to poor gas mileage in order to compansate the difference between transmission speed and engine speed? i've tried rev matching to downshift...and i've noticed that the car behaves differently from the other cars that i practice with (corolla GTS and 280z). is the FJcruiser designed for people who simply put the lever into a lower gear and ease the clutch to a downshift? i've been trying to save mileage by exiting freeways by utilizing neutral, rather than downshifting my way to a stop...but am i exerting efforts into something that doesn't save gas mileage? anyone else notice this???

 

[firetruck41]

when i purchased my FJc... the "rapes-man" mentioned that the vehicle is equiped with a 'power assisted clutch.' i never took it into consideration except for the fact that the FJc downshifts very smoothly without having to rev-match the manual transmission system on my 6 speed.

my question is, this 'power assisted' clutch system. is it the reason why the manual 4wd option still doesn't get better mileage than the automatic option? i've noticed that if i'm at a rolling speed and pop the shifter in neutral, the revs dont automatically drop down to idle level...they stay at about 1200 rpm?!?! could this contribute to poor gas mileage in order to compansate the difference between transmission speed and engine speed? i've tried rev matching to downshift...and i've noticed that the car behaves differently from the other cars that i practice with (corolla GTS and 280z). is the FJcruiser designed for people who simply put the lever into a lower gear and ease the clutch to a downshift? i've been trying to save mileage by exiting freeways by utilizing neutral, rather than downshifting my way to a stop...but am i exerting efforts into something that doesn't save gas mileage? anyone else notice this???

I don't think that has anything to do with mpg. Also probably doesn't have anything to do with enginve rpms while downshifting, etc. I've never really blipped throttle to match downshifts when slowing/coming to a stop on any car I've had, and have never known anyone that has, though I've always done it on my motorcycles. I am sure that most people downshift by easing out the clutch on all their cars and probably how the FJ was expected to be used.

If it truly does have "power assisted clutch" (haven't heard that before), it would probably only affect the effort of moving the pedal in/out. You should check your owners manual for the idle speed, I would bet that idle speed should be between 500-750 for a manual trans.

 

[saskdiesel]

I've never really blipped throttle to match downshifts when slowing/coming to a stop on any car I've had, and have never known anyone that has,

Then you should drive something with an SM420..

 

[FJCruiserOwnersGroup]

when i purchased my FJc... the "rapes-man" mentioned that the vehicle is equiped with a 'power assisted clutch.' i never took it into consideration except for the fact that the FJc downshifts very smoothly without having to rev-match the manual transmission system on my 6 speed.

my question is, this 'power assisted' clutch system. is it the reason why the manual 4wd option still doesn't get better mileage than the automatic option? i've noticed that if i'm at a rolling speed and pop the shifter in neutral, the revs dont automatically drop down to idle level...they stay at about 1200 rpm?!?! could this contribute to poor gas mileage in order to compansate the difference between transmission speed and engine speed? i've tried rev matching to downshift...and i've noticed that the car behaves differently from the other cars that i practice with (corolla GTS and 280z). is the FJcruiser designed for people who simply put the lever into a lower gear and ease the clutch to a downshift? i've been trying to save mileage by exiting freeways by utilizing neutral, rather than downshifting my way to a stop...but am i exerting efforts into something that doesn't save gas mileage? anyone else notice this???

the "power assist clutch" simply means that the clutch isn't a manual clutch; much like the brakes, it uses a hydraulic system with a reservoir to assist the driver in pushing the clutch. Most manual tranny cars have power assist clutches. Like, for example, the Mazda Miata.

The reason the manual FJC gets less MPG than the auto FJC is because the auto FJC is a part-time 4WD system.

If your vehicle is revving high, you should take it back to the dealership and have them look at it.

 

[freewheeling frank]

Do you mean it uses vacuum to enahnce the hydraulic effect? Like power brakes?

Also, I am used to double clutching whenever I downshift. I learned to drive in an FJ45 with no syncro mesh in first gear, and just got used to double clutching. So obviously I "rev match" when I downshift.

And how does leaving the car in nuetral as you exit the freeway help your mileage? Curious about that one...

 

[Koffer]

the "power assist clutch" simply means that the clutch isn't a manual clutch; much like the brakes, it uses a hydraulic system with a reservoir to assist the driver in pushing the clutch. Most manual tranny cars have power assist clutches. Like, for example, the Mazda Miata.

.

This is nothing new for Toyota
they have been doing this since the FJ25s

But they did offer a vacuum assist boost clutch on the diesels
see pix of a BJ70s

 

[Cali_FJC]

could be the salesturd is getting his panties confused with the clutch start cancel switch

 

[zagazowFJ]

i'm aware of how a hydraulic clutch works. but have never heard it referred to as a power assisted clutch. for example, i'll exit the freeway at 65 mph...and stick it in neutral. the tach will drop down to 1250 or so, then drop to 900/1000. and as the speed decreases, the tach will swing back up to 1250 as if the car is anticipating another downshift. it's weird, maybe i should post a vid. DUH!

 

[BigBlue]

I just got mine today and have notice the same thing. I think anticipating another downshift is exactly what it is doing. It's been a long time since I've owned a manual but this one sure does seem smooth.

 

[TINTOP]

I was curious about a power assisted clutch - About to look at a Toyota Coaster motor home - But coasting in neutral. Leave in gear, on over-run engine management will cut fuel to zero if engine is being driven by wheels. In neutral, fuel is needed to keep engine idling.

 

[1911]

my question is, this 'power assisted' clutch system. is it the reason why the manual 4wd option still doesn't get better mileage than the automatic option?

No. The reason the manual tranny FJC gets slightly less gas mileage than the auto tranny version is two-fold; 1) the manual has 3.9:1 differentials and the auto has 3.7:1, and 2) the manual is full-time 4WD and the auto is part-time (selectable) 4WD so the manual is always turning the front drive shaft, diff, and axles and that is a little more friction and drag.

 

[Elbert]

old school clutches used manual linkage to activate the clutch. New way is a hydraulic master cylinder that then feeds a slave cylinder via a hose from the master cylinder... Old school clutch setup took more physical force, than the new style hydraulic operated with slave cylinder.

 

[finderscuba]

Most clutches are hydraulic. The "power assist" is simply vacuum assist just like on your power brakes. Try pumping your clutch when the engine is off. It will get progressively harder to press, just like on power brakes. My 1990 HDJ81 has this same feature.

The revs issue you're describing has nothing to do with the clutch. It could be normal behaviour, or it could be related to maintaining sufficient vacuum to boost the brakes and clutch. In my diesel, vacuum is obviously created by a separate vacuum pump. If I pump the brakes or clutch, the engine rpms will increase slightly as it builds more vacuum. Probably different on your gas engine though.

And anyone that does not rev match on downshifts obviously has more money than brains. You'll prolong your clutch life and your u-joints. I've never owned an automatic in my life and with proper up and downshifts, I've never had to replace a clutch, ever. Blip the throttle while downshifting to match revs, let out the clutch smoothly and you've made your clutch happy. Also allows you to accelerate through a downshift without jerking. Letting the wheels drive the rpms up means more wear and tear on your clutch. Try this in a performance car entering a corner and you're sure to end up in the grass or worse, the wall!

Your assignment for the day, Google heel-toe downshifting.

 

[-MaTTi-]

The "power assist" is simply vacuum assist just like on your power brakes. T

There is no power assistant in FJ Cruiser´s clutch. http://www.pureautoparts.com/docs/2...al/Clutch/Clutch Master Cylinder/01800310.pdf