Shifting in a 1LE

[Mr. Wyndham]

Originally Posted by Bizaro

Let the clutch out slowly while shifting or else its going to jerk like crazy, these cars are temperamental like that .

Clutch is touchy.

I find that I can use it as an on/off pedal while in the high rpms, say...racing.

But I have to be careful to feather it from 1st to 2nd just burbling around town.

[cajun1le]

Well, I stand corrected on a few elements after having a chance to dig into a 6060-MM6.

• All 6 gears are linked to the output shaft, unlike a split configuration in regular immersive lubrication transmissions.
• There are no metal or brass syncros, but rather a wet disc clutch design similar to an automatic transmission. The clutch is glued in place and is water soluble. If a mild amount of water enters the transmission case, it will damage the syncro disc and can cause grinding during gear changes (hence why I will now change my fluid once a year).
• Lubrication is tied to the input shaft. Coasting in neutral while the clutch is engaged will not adversely affect the transmission since all gears are linked and moving at the same speed, no damage will occur.
• Coasting or towing in with the following conditions will damage the transmission due to a lack of lubrication: coasting for extended periods while the clutch is disengaged, or towing the vehicle with the rear tires on the ground and the drive shaft still connected to the transmission.
• There is a ring magnet to capture ferrous materials but to access it you have to disassemble the transmission case.

I'm not sure how many have the courage to say or do the right thing. But if I am wrong, I will admit it and correct it. I hope this helps and again "I stand corrected".

[gajagfan]

Originally Posted by White_SS/RS

Keeping the clutch in all the time puts unneeded pressure on your thrust bearing in the engine. That leads to thrust failures over time.

200K plus miles on the last WS6, and never an issue. mega miles on Z24 Cavalier back in the day, and never an issue. I am in agreement with keeping it in gear and don't think it is going to cause any trouble. I will take it out at a long light, but put it back in gear way early. I should not I am not in a major city (NY, ATL, Chicago, LA), but in a small city and rural areas with a fair share of traffic lights, so that may have some effect on the situation. In other words, keeping clutch in may be more of an issue if inner city driving is the norm.

[SchfiftyFive]

I dont have a 1LE but with my car I coast it out til about 1200 rpm's in overdrive which for me is 5th and then go into neutral and coast to the stop sign/light. This to me is the best of both worlds. I'm not coasting in neutral for an eternity for whatever damage that can cause over time and I'm not letting the engine die out after 1000 rpm. 1St to 2nd is also a bish for mine, I just give it a smidge of gas as I'm re-engaging the clutch as I slide into 2nd. I usually am at least 15 - 17 MPH as well. This helps alot with the 2nd jerkyness and 2nd gear having an attitude.

NOW the question I'm surprised you didnt ask as a new manual owner is OMG navigating the parking lot looking for a spot. Its a game of clutch and mouse(throttle) while in first. Often I come into a lane in 2nd, pop into neutral and coast into a spot towards the back where I can slide it without the clutch game. LOL

[White_SS/RS]

Originally Posted by cajun1le

I guess I have to dig into the weeds a little.

Does it apply some progressive pressure to the thrust bearing, yes it does. Although in the long run the wear, if any is negligible because it's a fluid bearing just like the journal/rod bearings and oil is being applied to it so long as the engine is running. Lugging a engine in a tall gear at low RPMs does far more damage because the force applied to the thrust bearing is equal to about 4-6 times the alternative. Not to mention, it's an impacting force that has the possibility of washing oil from the fluid bearing causing scaring and wear over time. So which method is worse? One that leaves oil at the bearing or one that washes it away?

But like I said before, you can do whatever you want. I'm just throwing out a few pointers from what I observe at my shop. As with everything there are pros and cons with whatever you decide to do. Its up to you to determine your risk level. I hope this helps.

<note to self> add this topic to the list of "topics to avoid" along with: religion, politics, when to change oil, how to winter/spring prep your car.... lol

Originally Posted by gajagfan

200K plus miles on the last WS6, and never an issue. mega miles on Z24 Cavalier back in the day, and never an issue. I am in agreement with keeping it in gear and don't think it is going to cause any trouble. I will take it out at a long light, but put it back in gear way early. I should not I am not in a major city (NY, ATL, Chicago, LA), but in a small city and rural areas with a fair share of traffic lights, so that may have some effect on the situation. In other words, keeping clutch in may be more of an issue if inner city driving is the norm.

Here is my experience with thrust failures. A few years back I was tearing down an LS1 to do some mods. The engine was running great at the time and there was no suspicion of any problems. When we got it apart we found the Thrust to be completely destroyed. We put quite a bit of research into determining the cause and found that the guy would always keep the clutch pedal to the floor when at a light and such.

If you think about it, sure you could say its a pressurized surface but it doesn't quite work that way. When you put pressure on one side of the trust it forces all the oil out and pushes it out the opposite side (path of least resistance) done long enough the oil film breaks down and you now have metal to metal contact. Typical clutch pressure is around 650kg or 1400psi. It doesn't feel that heavy because of hydraulics and mechanical leverage advantage but that load is directly applied to the thrust when the clutch pedal is pressed down. For reference the load on a main bearing is about 500-700psi and it survives, not because oil is there but because an oil wedge is created. The thrust relies on the mains oil wedge runoff and it exits either side, in the case of a depressed clutch the runoff goes to the side without pressure on it.

[cajun1le]

Ok, one more time and I'm done.

I've seen thrust bearing torn up a whole bunch of different ways, none of them were ever caused by a disengaged clutch while the engine is running (this covers my entire career of being in this trade). It is a fluid bearing designed to accept a reasonable amount of force, but not abuse. There is a slight, slight, slight, slight, slight chance during start-up where you may scar the thrust bearing because it is dry but with modern day lubricants and bearing design the chances of doing that is like winning the local lotto. To back all my talking points I went digging through the tech tip magazines that work provides and found this article from a few years back. I hope it sheds a little light on what is actually going on inside the LS1 that you were working on.

http://www.motor.com/article.asp?article_ID=1656

I'm rather curious how you came up with 1400 PSI? Because, I've measured it while messing around after hours and it takes about 150-300 lbs (depends on the age) of force needed to depress most pressure plates. I've never tested anything beyond a factory clutch, but I'm sure the pressure required is greater.

And just so you know, I'm not bitter at you. I just believe in giving out the right information, hence why I posted back to this thread in an earlier post after finally getting a chance to work on a 6060. In the past I've always worked on older traditional manual transmissions and what I mentioned above does apply to those configurations.

If I'm wrong, I'll admit it. If I'm correct, I'll back it up.

Originally Posted by SchfiftyFive

NOW the question I'm surprised you didnt ask as a new manual owner is OMG navigating the parking lot looking for a spot. Its a game of clutch and mouse(throttle) while in first. Often I come into a lane in 2nd, pop into neutral and coast into a spot towards the back where I can slide it without the clutch game. LOL

LOL

[White_SS/RS]

Seems like the theme in the article is "constant forward pressure" as seen in always keeping the clutch in. I'm not saying it's the only way to destroy the thrust. I'm just saying your not doing it any benefit by keeping the pedal to the floor longer than what is needed to change a gear. The first paragraph under overloading supports my idea, "riding the clutch"

[cajun1le]

Its the type of pressure from torque loading the engine the damages thrust bearings, and not disengaged clutches. The article clearly states that fact. Riding a clutch is totally different holding the clutch in. One state is a controlled action the other is not.

[White_SS/RS]

Originally Posted by cajun1le

Its the type of pressure from torque loading the engine the damages thrust bearings, and not disengaged clutches. The article clearly states that fact. Riding a clutch is totally different holding the clutch in. One state is a controlled action the other is not.

What is the physical difference to the thrust between holding the clutch in and riding it? Both exert pressure on the thrust. I'm failing to see any difference here.

Torque is a twisting action so I don't know how that plays into linear pressure when the trust is responsible for providing linear control of the crank

[cajun1le]

Because you're unable to see the difference between the two types of forces at work is also why you're unable to understand what's really going on. This also applies to your understanding on "load torque/torque loading" and its effects.

[White_SS/RS]

Originally Posted by cajun1le

Because you're unable to see the difference between the two types of forces at work is also why you're unable to understand what's really going on. This also applies to your understanding on "load torque/torque loading" and its effects.

I think your the one who is misunderstanding. I don't even know where you are getting torque loading or torque load. Are you referring to 'load from a torque converter?'

Simple question, Is there load on the thrust bearing when the clutch pedal is pushed? yes or no?

[cajun1le]

Originally Posted by White_SS/RS

I think your the one who is misunderstanding.

Is there load on the thrust bearing when the clutch pedal is pushed? yes or no?

The difference is one force is a sharp and impacting where as the other is slow and progressive. The bearing can handle slow and progressive forces because it does not wash the oil away, impacting forces does. That is the key difference. I stated that and the article states that and any knowledgeable technician worth his salt will tell you exactly the same thing. I'm really not sure how else to describe it in a way that you will understand.

[White_SS/RS]

Originally Posted by cajun1le

The difference is one force is a sharp and impacting where as the other is slow and progressive. The bearing can handle slow and progressive forces because it does not wash the oil away, impacting forces does. That is the key difference. I stated that and the article states that and any knowledgeable technician worth his salt will tell you exactly the same thing. I'm really not sure how else to describe it in a way that you will understand.

I actually have a great understanding of mechanics. Anyway, lets take riding the clutch as an example. Its not a sharp impact, its a continuous load and it states in your article as well as many others that it is a cause of thrust failure. So is it really about how the load is applied or is it that a load simply exists?

[cajun1le]

Originally Posted by White_SS/RS

I actually have a great understanding of mechanics. Anyway, lets take riding the clutch as an example. Its not a sharp impact, its a continuous load and it states in your article as well as many others that it is a cause of thrust failure. So is it really about how the load is applied or is it that a load simply exists?

It is how the force is applied. By "riding the clutch" you are inducing a impacting linear force (load torque or torque loading) up the crankshaft. The reason for that when the clutch is partially engaged there is not a constant pressure acting against the pressure plate which causes the clutch to bite sporadically while in gear. It's those sporadic bites of the clutch amplifies the torque load to the engine which then produces a stronger linear impacting force that strikes the thrust bearing.

By disengaging the clutch and holding it there will not harm the thrust bearing, the article states that fact and is quite specific. Fully disengaging the clutch is not riding the clutch. One action is under no load(disengaged) and the other is under a load while partly engaged(riding). Below is an excerpt from the tech tip article mentioned before.

The thrust bearing must be able to absorb forward thrust loads that are delivered by the transmission, torque converter or clutch. Thrust bearing overloading can be caused by any number of problems, including poor crankshaft surface finish (too rough and/or wavy), excessive “riding” of the clutch pedal, improper clutch release bearing adjustment, excessive torque converter pressure or an improperly mounted front crank-driven accessory (a/c compressor, power steering pump, supercharger, etc.).
If a failed thrust bearing is found, don’t automatically blame the engine builder. It’s very possible that the transmission or a transmission-related area is the culprit. If the action of the clutch, torque converter or automatic transmission hydraulic force applies constant or frequent forward pressure on the crankshaft, certainly the front thrust bearing surfaces are going to take a beating. In the case of a manual transmission, this can be caused by driver error, as a result of continuously riding the clutch.

In the case of a manual transmission, also check the clutch release bearing for proper adjustment. If the release bearing shows signs of extreme wear and/or overheating, this is a clear indication that the driver has been routinely riding the clutch pedal and/or slipping the clutch.

In your case, I'm more inclined to believe that it was probably the constant slipping or riding of the clutch that damaged the bearing, not sitting at the light with the clutch disengaged.