How Long Will A Clutch Last???

Smartfor2guy · 01-25-2008, 03:14 PM

This is a question for one of our techs or anyone knowlegable about the clutch system in the Smart. Does the Smart have a normal clutch disc and pressure plate or what kind of system does it use??

**jwight** · 01-25-2008, 03:29 PM

Not a lot of time for 451 experience yet but I imagine the 450 drivers will have some input on this.

Fredvon4 · 01-25-2008, 04:13 PM

I do not have the answer to life but do under stand the system

It is a typical clutch and pressure plate set up with out a mechanical or hydraulic clutch pedal for the operator... a computer de-clutches or engages with a signal to an electric actuator.

Apparently the creep mode will allow it to slip some... not sure on this but creep mode is an area I am concerned with... on the other hand low gear and final drive is a real low ratio, so perhaps it does not really slip it a lot...just don't know yet

Brits seemed to have a lot of posts about Gen 1 clutch repair but I got the sense it was the high mileage vehicles...in other words nothing in the forums got my hackles up about premature failure...

Gen two posts seemed to be more concerned with an internal seal that crapped out contaminating the clutch area...this got my attention because the repair is damned expensive time wise for a cheap $3.00 seal

It will be some time before we know if the re design fixed any of the earlier short comings

Smartfor2guy · 01-25-2008, 04:18 PM

Quote:

Originally Posted by Fredvon4

I do not have the answer to life but do under stand the system

It is a typical clutch and pressure plate set up with out a mechanical or hydraulic clutch pedal for the operator... a computer de-clutches or engages with a signal to an electric actuator.

Apparently the creep mode will allow it to slip some... not sure on this but creep mode is an area I am concerned with... on the other hand low gear and final drive is a real low ratio, so perhaps it does not really slip it a lot...just don't know yet

Brits seemed to have a lot of posts about Gen 1 clutch repair but I got the sense it was the high mileage vehicles...in other words nothing in the forums got my hackles up about premature failure...

Gen two posts seemed to be more concerned with an internal seal that crapped out contaminating the clutch area...this got my attention because the repair is damned expensive time wise for a cheap $3.00 seal

It will be some time before we know if the re design fixed any of the earlier short comings

Do you have any idea what mileage was at the time of seal failure? I'm sure the 451 is not a completely new design, but although it may be because of the different engine AND transmission. Normally the extended warranties are not a good buy , but maybe for peace of mind on a new design??

Karl Roth · 01-25-2008, 04:58 PM

Only you can decide what "peace of mind" is worth to you. We are all going to die guaranteed the question is when.
karl

Fredvon4 · 01-26-2008, 08:58 AM

The most info on the "seal" problem is from a Brit poster who seems to be a Smart Tech at Smarts 'R Us...a non MB shop....some of his other posts make me think he has an Axe to grind (not totally impeaching, but a concern about agendas)

Anyway, he is fairly prolific about the problem and says it is a getrag internal problem and he doubts MB fixed it in the 451...

in the Gen 1 some, and Gen 2 450 I find a lot of ref to this problem

Remember, the real reason people post on forums is when they have a problem they don't like the answer to

In this case the failure is outside of warranty, is a known problem, and the owner is mad about the cost of repair... thus the high post count on this specific problem caught my attention

Obviously there are not enough miles or time on the 451 to know if, or if not, they (MB/Getrag) fixed it

My strategy is to follow the German and Brit sites for the next 18 months and see if this problem surfaces relating to the 451s...if the seal craps out in enough out of warranty cases, I will pay for a 1~2 yr extension, banking $300~500 against a $1000+ dollar potential repair

Still a loss...arrrrgh!

mdfortwoguy · 01-26-2008, 09:15 AM

I personally would rather not have the creep feature.

On the US spec cars I drove at the DC road show, it seemed to have a minor shudder when it was trying to creep. I drive a manual every day, so the feel doesn't bother me - its more about knowing the mechanics of the clutch slipping that cause the shudder.

I didn't pay attention to the tach to see when it really engages fully - I should have. My VUE has a decent amount of low end torque, and can launch with no shudder or anything from about 1200 RPM... so I'd imagine that this is engaging a bit higher.

Carnut · 01-26-2008, 09:18 AM

Since may of us are manual tranny oriented, why not get into the habit (no jokes please) of shifting into neutral while stopped to lessen the creep?

Fredvon4 · 01-26-2008, 09:34 AM

Carnut...that is my initial thought.... gonna have to see real world if it really does slip a lot (watch rev o meter) or is really full engaged and gear ratios are low enough for a crawl funtion... I think if it does slip by design this is not good for long life of clutch and may generate a lot of heat that may be the cause of the seal failure...

mdfortwoguy · 01-26-2008, 09:49 AM

I'd be curious to see the logic behind the system.

From my limited experience... it didn't feel like this engaged until the vehicle had started to roll. Tied with the anti-roll back feature, I get the sense that the creep is completely disabled while idling at a stop.

Hmm, I'd be pretty sure this thing has a throwout bearing... I wonder how that's going to go into play for durability.