Clutch Actuator adjustment

132456 Views 67 Replies 28 Participants Last post by shoalsgary, 9 mo ago

WhiteNBlack08

Discussion Starter · Mar 6, 2012 (Edited by Moderator)

I figured I'd post this information for those of you getting up there in mileage like me.

As many of you may know, my Smart is getting really close to 100K miles. In fact, I will pass that milestone this month. I've noticed over the last 1K miles or so that my clutch didn't seem to engage quite like it used to. Seemed to "slide" into each gear, like when a conventional clutch needs adjusted.

Since I was the first to brave tearing an actuator apart, I figured I might as well be the first to adjust one.

As the clutch wears, the facings become thinner, and the engagement point moves. I assumed that the ECU in the smart would adjust for this and maintain itself. Apparently is doesn't(or at least not to my liking). I have an early '08 with the original clutch, so yes, mine does have 100K on it.

I crawled under the car, marked the location of the actuator on the three mounting lugs with a Sharpie, then loosened the three retaining bolts. The unit can then slide back and forth. To adjust, you want to move it out towards the driver side of the car. I know this can seem counter-intuitive, but understand that the clutch fingers are cantilevered in the pressure plate, so as the clutch wears, the fingers move out. I moved my actuator out about 1/8". Locked it down, and took it for a drive.

WOW! what a difference. The clutch engages when it should, and each gear change is like a rock. It hasn't felt this good in quite a while. I'm not saying the 1/8" is gospel for everyone, but it definitely worked for my car. I am much happier with the gear changes, and I'm sure I just added a lot of miles to the life of my clutch.

Obviously this is not a recommended service proceedure from smart, and as always try at your own risk. It worked for me, just figured I'd throw it out there for the community as a whole.

Here is the official adjustment proceedure from MB WIS catalog:
Smart Car of America Forum

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Critical Thinker

· #2 · Mar 6, 2012

Is this a clutch actuator adjustment or a clutch adjustment? The only reason I ask is because a conventional clutch is usually self-adjusting.

WhiteNBlack08

Discussion Starter · #3 · Mar 6, 2012

Critical Thinker said:
Is this a clutch actuator adjustment or a clutch adjustment? The only reason I ask is because a conventional clutch is usually self-adjusting.

I didn't touch the clutch itself, just moved the actuator slightly. I figured it was worth a try, and a lot cheaper than paying a dealership $200+ to do a clutch re-teach.

I'm not a "techie", and have no way of reading or understanding the base code in the TCU, so I have no idea if the smart engineers built any kind of algorithm into the TCU to compensate for clutch wear. I assume it's there, because clutch wear is a natural occurance in any vehicle, but I don't know that for a fact. I can tell you, my adjustment made a big difference in the way my smart drives.

Reactions: 1

Critical Thinker

· #4 · Mar 6, 2012

That's cool...glad it worked for you. I guess if the clutch is self-adjusting, then it would make sense to have some kind of automatic adjustment of the actuator too. But I have no real knowledge of how it works on the smart. Your attachment was helpful though...

chieftmc

· #5 · Mar 6, 2012

Way to go Greg :woohoo:

:worship: You're my hero :worship:

Thanks once again for "braving" the frontier :cowboy:

All right MOD's, you know what to do with this one

SmartDigger

· #6 · Mar 6, 2012

Good call good info. now it is where it should be.

SLIVERS

· #7 · Mar 6, 2012

Critical Thinker said:
Is this a clutch actuator adjustment or a clutch adjustment? The only reason I ask is because a conventional clutch is usually self-adjusting.

A conventional (mechanical linkage system) is not self adjusting. As the disk wears the fingers move out and the linkage needs to be adjusted,
A hydraulic clutch is somewhat self adjusting, within the range of the hydraulic actuator.
The smart system would for lack of better words be mechanical.
As stated in original post as the disk wears the fingers move out.
At some point the range of travel of the clutch actuator would reach a limit.
As stated in the "clutch actuator removal/install" instructions the actuator is moved against the release lever and then 3 graduation lines away.
The lever can be seen in this photo going from about 11 o'clock to 5 o'clock. The actuator contacts the lever at about the 5 o'clock position (from the back in the photo).

The only reason I have not tried experimenting is I live 600 miles from dealer if I needed to "plug" it in.

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dhirtle

· #8 · Mar 7, 2012

I recall seeing a video re: lubricating the actuator by pulling the rubber boot back and liberally spraying lithium grease up inside the mechanism. I think that was on a 450. The actuator on the 451 looks to be a bit beefier but basically the same design. Is that anything that any of you recommend doing? And if so at what intervals.

jwight

· #9 · Mar 7, 2012

http://www.smartcarofamerica.com/forums/f183/clutch-actuator-maintenance-40415/

There is no set interval for this DIY procedure - smart does not have the clutch actuator on their list of periodic maintenance items.

dhirtle

· #10 · Mar 7, 2012

Yeah I'm clear on that front - how about anybody else? Every 30K? Wait until shifting gets sketchy?

WhiteNBlack08

Discussion Starter · #11 · Mar 7, 2012

dhirtle said:
Yeah I'm clear on that front - how about anybody else? Every 30K? Wait until shifting gets sketchy?

It took almost 98K before mine was noticable enough to do this little tutorial. I also do a lot of highway driving, very little in town driving. If you do all stop and go, you may need to do this sooner than I did. Personally, I would say every 60K would be plenty soon enough. I plan on pulling my actuator yearly to clean and re-lube.

As I've said before, I'm a do-it-yourself kind of guy. I've worked on cars my whole life. Preventative maintenance is the cheapest insurance you can get for a car.

Hope this helps.

Reactions: 1

dhirtle

· #12 · Mar 7, 2012

WhiteNBlack08 said:
It took almost 98K before mine was noticable enough to do this little tutorial. I also do a lot of highway driving, very little in town driving. If you do all stop and go, you may need to do this sooner than I did. Personally, I would say every 60K would be plenty soon enough. I plan on pulling my actuator yearly to clean and re-lube.

So you did the cleaning/ lubrication, and the adjustment (first post in this thread) ?

chieftmc

· #13 · Mar 7, 2012

WhiteNBlack08 said:
It took almost 98K before mine was noticable enough to do this little tutorial. I also do a lot of highway driving, very little in town driving. If you do all stop and go, you may need to do this sooner than I did. Personally, I would say every 60K would be plenty soon enough. I plan on pulling my actuator yearly to clean and re-lube.

As I've said before, I'm a do-it-yourself kind of guy. I've worked on cars my whole life. Preventative maintenance is the cheapest insurance you can get for a car.

Hope this helps.

Make sure you document it when you change out that clutch

Thanks again

mhornfeck72205

· #14 · Mar 7, 2012

dhirtle said:
Yeah I'm clear on that front - how about anybody else? Every 30K? Wait until shifting gets sketchy?

Figured I'd try it now even though i'm at 45k. Notched it out by 1 marking and took it for a spin. Fantastic rolling 2nd gear accel now. no more long drag before it catches. much stronger bite i guess you could say. Thinking i'll probably try a corner into 1st gear and see how that bites up too.

Reactions: 1

WhiteNBlack08

Discussion Starter · #15 · Mar 7, 2012

dhirtle said:
WhiteNBlack08 said:

It took almost 98K before mine was noticable enough to do this little tutorial. I also do a lot of highway driving, very little in town driving. If you do all stop and go, you may need to do this sooner than I did. Personally, I would say every 60K would be plenty soon enough. I plan on pulling my actuator yearly to clean and re-lube.

So you did the cleaning/ lubrication, and the adjustment (first post in this thread) ?

Click to expand...

Actually, I took the actuator apart and cleaned and lubed it last September, shortly before Outsmarting the Dragon. I'll do that again this fall, and see how the Lithium grease is holding up.

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tahoesmart

· #16 · Mar 10, 2012

Correct me if im wrong but i was under the impression that the clutch on the 451 was only used for driving off from a standstill or when you were stopped. With each gear change (first through fifth) the gear speeds are matched up and then changed with no need for the clutch (the 'computers' in the Smart take over the throttle to control this and do the shifting). Short of like how you would shift a conventional 5 speed without using the clutch, ei matching the next gear. And the clutch would obviously only be engaged when coming to a stop.

Great write up by the way, but now im as confused as ever. I understand the need to adjust the clutch but it has been mentioned several times that the clutch was slipping with each gear change, and that adjusting it helped

. If i am correct then the clutch would not be used with each gear change and just for initial drive-off and coming to a stop.

Please educate me......

WhiteNBlack08

Discussion Starter · #17 · Mar 11, 2012

tahoesmart said:
Correct me if im wrong but i was under the impression that the clutch on the 451 was only used for driving off from a standstill or when you were stopped. With each gear change (first through fifth) the gear speeds are matched up and then changed with no need for the clutch (the 'computers' in the Smart take over the throttle to control this and do the shifting). Short of like how you would shift a conventional 5 speed without using the clutch, ei matching the next gear. And the clutch would obviously only be engaged when coming to a stop.

Great write up by the way, but now im as confused as ever. I understand the need to adjust the clutch but it has been mentioned several times that the clutch was slipping with each gear change, and that adjusting it helped . If i am correct then the clutch would not be used with each gear change and just for initial drive-off and coming to a stop.

Please educate me......

The clutch is actuated with each gear change. That is the reason each shift takes as long as it does. If you hung a camera under the car, you would see the actuator move every shift. You are correct that the computer also modulates the throttle as well. It's just like a standard 5 speed, only the computer does all the work.

Hope this clears it up a little.

nathlar

· #18 · Mar 17, 2012

I have 58,000 miles on my 2008. I'm 80% in town driving and carry about 200 lbs of tools in the back. It is my rolling toolbox.

Last week I picked up my daughter and her sleepover gear, figure about another 150lbs on board. The clutch rumble on take-off was horrible and I figured I needed a new clutch. After reading this forum, I found the actuator and moved it two notches to the drivers side.

Everything is perfect again, thanks for the advice. Hopefully I'll get another 60K out of this clutch.

SmartDigger

· #19 · Mar 17, 2012

Maybe the adjustment should be performed every 50,000-60000 miles

jimvw57

· #20 · Mar 17, 2012

With around 50K on my clutch, (replaced at around 16K with the transmission) it still feels OK, I think, but maybe worth a adjustment just to see if it feels better...

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