a silly question about the transmission

[TerminatorX5]

[bulkwarrior]

ok, if the torque converter is slipping, wouldn't that shorten it's life? If the torque converter is shot the tranny is bad, right?

[TerminatorX5]

by the same token using the brakes will shorten the life of the rotor... the TC has longer lifespan than the rotor but just because you use up the rotor's life, you will not stop stopping... that sounds weird - stop stopping... hmmm... i need to go home - too much time at work... lol...

[SlickGT1]

Yes there are clutch packs in the torque converter. They are oil pressure controlled. See again, we are back at oil pressure. Taking away that pressure, and applying it at every stop is not good. You don't give the trans enough time to re-establish that said pressure, and then take off. Brakes are much cheaper, use them.

If the TC blows up, yes, it could grenade into the transmission, taking transmission with it. You will feel shuddering and whining when the TC is failing.

[bulkwarrior]

On average, how long(how many miles) does a X5 auto tranny last? My X5 is 110k miles. Had another small car whose tranny needed replacement at 170K. I had to donate it because the cost of replacing tranny exceeded the remaining value of that car. Does anyone here had to replace their X5 tranny? At how many miles? Thanks.

[blktoptrvl]

Originally Posted by TwinTurboGTR

its the same argument with a manual. When people come to a stop, they will double clutch and downshift and use engine breaking to slowdown and use the brakes at the very end. When some choose to shift into neutral and use all brakes. SO what's the difference? Some argue that the first way, you wear the clutch out faster because you are doubling up on gear use and for the second method, people say you will wear out brakes faster. IMHO, brakes are a whole hell of a a lot cheaper and easier to replace than a clutch.

Also...

When you come to a stop in a manual, you should put it in neutral and let go of the clutch pedal, otherwise you are putting unnecessary pressure on the hydrolics (or cable if is is old style). Even worse, you are putting a lot of wear on the throw-out bearing.

You have to go through all the same pain to replace this bearing as you do the entire clutch when it wears out so you might as well replace all clutch components at this time. All unnecessary expense.

[JCL]

No benefit to putting an automatic transmission in neutral or park at a traffic light. It is also less safe, since it eliminates the opportunity to move in the event of a pending collision. There is a miniscule amount of heat created by the torque converter at idle, easily handled by the cooler. Bulk, don't think of the torque converter as a clutch. It is a fluid drive, as opposed to a mechanical drive. When there is insufficient pressure (ie at idle) the drive is not engaged. Nothing is wearing. Your are turning one part of the torque converter, and that creates a slight drag, which lowers your rpm just enough (in your case) to feel a vibration. Adjust the idle and that will go away. The clutch packs in the torque converter that were mentioned above are not part of the drive at idle, they are lock-up clutches only used at higher road speeds, nothing to do with sitting at idle.

With a manual transmission, you should be in neutral at a traffic light. Sitting with your foot on the clutch will get you a fail in a driver's license exam, because it is considered that if your foot slips off the clutch you will shoot out into traffic. More importantly, when you have your foot on the clutch for an extended period of time you are abusing the throw-out bearing. Blktoptvl, I read the whole thread before someone (you) mentioned the throwout bearing, I couldn't believe it. Seems manual transmissions are a dying breed, lol.

[bulkwarrior]

Thanks, JCL, your post is very knowledgeable and insightful. When I drove a stick(long time ago), the primary reason for me to put the foot on the clutch and engage it a little is, there are a lot of slopes in this area. When I stop at a upward slope, I had to do this because otherwise the car will slip backwards and scare the people behind me. LOL.

[JCL]

That is even worse, because you are wearing the clutch as well as the throw-out bearing.

Both our daughters learned to drive a stick at 16. We lived on the side of a mountain. They had to do repeated start/stops on hills, at every four way stop, and in several different vehicles that all had different clutches. I taught them with the use of the handbrake, but the driving instructors wanted them to be able to do it without touching the handbrake. It is all in the coordination.

[SlickGT1]

Originally Posted by JCL

No benefit to putting an automatic transmission in neutral or park at a traffic light. It is also less safe, since it eliminates the opportunity to move in the event of a pending collision. There is a miniscule amount of heat created by the torque converter at idle, easily handled by the cooler. Bulk, don't think of the torque converter as a clutch. It is a fluid drive, as opposed to a mechanical drive. When there is insufficient pressure (ie at idle) the drive is not engaged. Nothing is wearing. Your are turning one part of the torque converter, and that creates a slight drag, which lowers your rpm just enough (in your case) to feel a vibration. Adjust the idle and that will go away. The clutch packs in the torque converter that were mentioned above are not part of the drive at idle, they are lock-up clutches only used at higher road speeds, nothing to do with sitting at idle.

With a manual transmission, you should be in neutral at a traffic light. Sitting with your foot on the clutch will get you a fail in a driver's license exam, because it is considered that if your foot slips off the clutch you will shoot out into traffic. More importantly, when you have your foot on the clutch for an extended period of time you are abusing the throw-out bearing. Blktoptvl, I read the whole thread before someone (you) mentioned the throwout bearing, I couldn't believe it. Seems manual transmissions are a dying breed, lol.

No one mentions the throw out bearing, because those that know how to drive, don't destroy them. Most of us don't even change the clutch till 150k miles. And quite a few of us, can still shift without a clutch. lol. Yes manuals are a dying breed, which is a shame. I am looking for a 3.0 X5 on stick though. So hopefully I will get my first manual SAV. Keeping the 4.8 though.