Is this the reason that automatic tranny cars with overdrive have the overdrive-off button? (besides for towing, etc.)
Because driving around in too high a gear puts undue stress on the transmission, yes? I often think of the example of riding a bicycle in too high a gear for your speed. This brings awareness of the improper gearing in the form of straining and pain. Too bad we don't have pain gauges on cars. Then I could point to it and say to my wife "SEE?" Brian On 5/24/07, Mike Canfield <[EMAIL PROTECTED]> wrote:
Actually Phillip, the exact opposite is true with diesel engines and manual transmissions. Most failures I have encountered occured due to very high temperatures generated by large amounts of torque running in high gears. There is MUCH more stress on the input and mainshaft bearings of a manual tranny under full torque in a higher gear. The lower the gear the better for the tranny but the worse for everything behind the tranny. Mike ----- Original Message ----- From: "Fmiser" <[EMAIL PROTECTED]> To: "Mercedes Discussion List" <mercedes@okiebenz.com> Sent: Thursday, May 24, 2007 1:25 PM Subject: Re: [MBZ] Anybody ever swap a 5-speed into 123 wagon? > It seems than at Thu, 24 May 2007 11:10:51 -0400, Allan wrote: > >> I recall a statement on this list that Mercedes never paired a >> turbodiesel motor with a manual transmission, at least not in the era >> we're discussing. > > In the USA, I know that's true - but I recall hearing that in > Europe a turbo/manual combination was available. > >> People have put manual transmissions in W123 turbodiesels, but the >> torque of the motor is more than the transmissions were designed to >> handle, and they tend to break in a relatively short time. > > The biggest danger in over-torque is in low gear. The input > torque is multiplied by the gear ratio resulting in _lots_ of > torque at the output. > > The hot-rod big trucks will put 1000+ hp/2500+ lb-ft engines in > front of transmission spec'ed for 1800 lb-ft. The transmission > survives because the _driver_ is smart enough to avoid having > the engine develop maximum power in the lower gears. Once the > transmission is in high range the driver can actually use the > engine power that's available. > > My I-have-no-real-info-but-I'm-going-to-guess-anyway opinion is > that the same would be true for our cars. > > -- Philip > > _______________________________________ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
